160.78-O2 — YMC2 Mod A Centrifugal Chiller with OptiView Control Center, Control Panel Operation Guide

Document type	Operation Guide
Document number	160.78-O2
Equipment	YMC2 Magnetic Bearing Centrifugal Chiller
Brand	YORK
File size	14.6 MB

Fault codes in this document

Run messages

Code / display	Meaning	Cause	Action	Page
WARNING – VSD DC BUS ACTIVE	Non-annunciating alert that the DC Bus is precharged or pre-regulated for a state outside of chiller run.	Set when the VSD indicates a precharge or pre-regulated state or DC Bus voltage >50 V in the stopped state.	A countdown timer shows with this message to indicate the time remaining in a precharge or pre-regulate command while stopped.	114

Start inhibit messages

Code / display	Meaning	Cause	Action	Page
LINE FREQUENCY NOT SET	Chiller prevented from starting because the Line Frequency setpoint is invalid.	This start inhibit is set when the Line Voltage setpoint is INVALID. Line Frequency is set invalid on a new or cleared BRAM until programmed.	Set on a new or cleared BRAM; remains until the Line Frequency is programmed.	114
LINE VOLTAGE NOT SET	Chiller prevented from starting because the Line Voltage setpoint is invalid.	This start inhibit is set when the Line Voltage setpoint is INVALID. Line Voltage is set invalid on a new or cleared BRAM until programmed.	Set on a new or cleared BRAM; remains until the Line Voltage is programmed.	114
PRV NOT CALIBRATED	Start inhibited because the Pre-rotation vanes calibration has not been done.	The Pre-rotation vanes calibration procedure has not yet been performed.	Perform the Pre-rotation vanes calibration procedure (PRV Calibrate screen; only available if the chiller is stopped).	114
VGD NOT CALIBRATED	Start inhibited because the Variable Geometry Diffuser calibration has not been done.	The Variable Geometry Diffuser calibration procedure has NOT yet been performed.	Perform the VGD calibration procedure (VGD Calibrate screen).	114

Warning messages

Code / display	Meaning	Cause	Action	Page
WARNING – MBC – LANDING COUNTER HIGH	MBC landing counter has reached its warning threshold of shaft landing events.	The MBC landing counter has accumulated 30 events where the motor shaft displacement exceeded 120 µm (80% of the air gap space to the touchdown bearing) while shaft rotation is detected.	Released only when a service technician checks the shaft air gap measurement for acceptability and resets the MBC according to the driveline service manual YORK YMC2 Service Manual (Form 160.78-M2).	115
WARNING – MBC – ROTATION MODE OFF	MBC reports Rotation Mode OFF while the microboard is commanding it ON.	During the time the MBC Rotation Mode is commanded ON by the microboard via serial comms this warning is set if the MBC reports Rotation Mode is OFF by serial comms.	Inhibited if MBC communication is not initiated and during the first 15 seconds after the Rotation Mode is commanded ON. Released when Rotation Mode status matches the microboard command to the MBC.	115
WARNING – MOTOR – HIGH CURRENT LIMIT	Motor current has reached the Motor Overload current limit; capacity control is overriding to reduce current.	The chiller motor current is greater than or equal to the Motor Overload current limit. The Motor Overload current limit is predetermined from the motor model and Maximum VSD Output Current.	While this condition is in effect, chiller capacity control is in override to reduce current. Automatically clears when the motor current decreases below this limit.	115
WARNING – CONDENSER – HIGH PRESSURE LIMIT	Condenser pressure exceeds the High Pressure Warning Setpoint; capacity override active.	The Condenser Pressure exceeds the High Pressure Warning Setpoint threshold, programmed by a Service technician logged in at SERVICE access level.	While in effect, the chiller capacity is in override to reduce pressure. Automatically clears and normal LCHLT capacity control is restored when the Condenser pressure decreases to below the Setpoint.	115
WARNING – CONDENSER OR EVAPORATOR XDCR ERROR	Evaporator pressure transducer reads higher than the condenser transducer — indicative of a transducer failure.	The Evaporator pressure Transducer is indicating a higher pressure than the Condenser pressure Transducer after the chiller has been running for 10 minutes. This is indicative of a Condenser or Evaporator Transducer failure.	Displayed until the condition clears and the WARNING RESET Keypad button is pressed in OPERATOR (or higher) access mode. Condition not checked in Brine mode.	115
WARNING – CONDENSER OR VGD SENSOR FAILURE	Stall (discharge) pressure transducer and condenser pressure transducer outputs disagree; VGD held full open while the warning stands.	The difference between the Stall Pressure Transducer output (discharge pressure) and the Condenser Pressure Transducer output has exceeded 0.28 VDC for 3 continuous minutes while the chiller was running. Both transducers measure essentially the same pressure and should be within the specified tolerance.	Must be manually cleared. Displayed until the transducer outputs are within the acceptable range of each other and the WARNING RESET button is pressed in SERVICE access level. While displayed, the VGD is driven to the full open position and held; when cleared, the VGD returns to normal operation.	115
WARNING – EVAPORATOR – LOW PRESSURE LIMIT	Evaporator pressure has fallen to the warning threshold; capacity control overriding to raise suction pressure.	The Evaporator pressure has decreased to the Warning threshold. Fixed in Water cooling applications; in Brine applications the threshold is a fixed amount above the programmable safety shutdown threshold determined by the brine solution at the YORK Factory. Warning/reset thresholds (psig): R-134a 27.8 / 28.8 (water), 1.7 / 2.7 above safety setpoint (brine); R-513A 32.0 / 33.0, 1.8 / 2.8; R-1234ze 16.7 / 17.7, 1.3 / 2.3; R-515B 16.5 / 17.5, 1.3 / 2.3.	While in effect, the chiller capacity control is in override to increase suction pressure. Automatically clears and normal LCHLT capacity control is restored when the Evaporator pressure increases to the reset value.	115
WARNING – EXCESS SURGE DETECTED	Surge Window Count has exceeded the Count Limit (applies only if Surge Protection SHUTDOWN is Disabled).	This applies only if Surge Protection SHUTDOWN feature is Disabled. The Surge Window Count has exceeded the Count Limit.	Can be manually cleared after the Surge Window Count is less than or equal to the Count Limit, or the SHUTDOWN feature is Enabled, or the chiller is stopped. To clear, press WARNING RESET button on HOME Screen when logged in at OPERATOR (or higher) access level.	116
WARNING – MOTOR – HIGH HOUSING TEMPERATURE	Motor housing temperature at or above the warning level.	The Motor Housing Temperature is greater than or equal to 167°F (75°C).	Released when Motor Housing Temperature is less than 158°F (70°C).	116
WARNING - MOTOR – HIGH WINDING TEMPERATURE	An enabled motor winding temperature has exceeded the warning threshold.	Occurs when any of the enabled motor winding temperatures exceeds 275°F (135°C) for 3 continuous seconds.	Automatically clears when all winding temperatures decrease below the warning threshold. Will not act on any individual winding temperature sensor disabled with the TEMPERATURE DISABLED Setpoint on the Motor Details Screen.	116
WARNING – REAL TIME CLOCK FAILURE	BRAM / real-time clock failed its power-up test.	During the initialization process when power is applied, test data is written to the BRAM battery backed memory device (IC location U52 on Microboard), read back and compared; if the read data is not the same as that written, the BRAM and Real Time Clock operation is assumed defective.	The BRAM should be replaced by a qualified Service Technician. Automatically clears when the BRAM problem has been solved.	116
WARNING – SETPOINT OVERRIDE	Blank or failed BRAM detected at power-up; all setpoints reverted to defaults.	A blank BRAM battery-backed memory device (IC location U52 on Microboard) or a failure of this device was detected during initialization. Any or all of the programmed Setpoints could have been corrupted; therefore all Setpoints have been automatically changed to their Default values.	All Setpoints will have to be programmed to their desired values. Clears when the WARNING RESET button is pressed in OPERATOR (or higher) access mode.	116
WARNING – VSD – INPUT VOLTAGE IMBALANCE	Supply line-to-line voltage imbalance above 5%.	Line voltage imbalance is calculated for every VSD communications cycle as Vimb% = max(\|Vab-Vavg\|,\|Vbc-Vavg\|,\|Vca-Vavg\|) x 100%/Vavg. If Vimb% exceeds 5% continuously for 45 seconds, the warning is displayed.	The 45 second timer resets and the warning clears if three consecutive imbalance readings fall below the 5% threshold.	116

Cycling shutdown messages

Code / display	Meaning	Cause	Action	Page
CHILLED LIQUID – FLOW SWITCH OPEN	Loss of chilled liquid flow signal while running or starting.	The Chilled Liquid Flow Switch has remained open for 5 continuous seconds while the chiller was running, in soft shutdown, or at least 45 seconds after MBC startup is initiated.	The chiller will automatically restart when the flow switch closes.	117
CONDENSER – FLOW SWITCH OPEN	Loss of condenser liquid flow signal while running.	The Condenser water flow switch has remained open for 5 continuous seconds while the chiller was running or in soft shutdown. This check is bypassed until System Run is achieved.	The chiller will automatically restart when the flow switch closes.	117
CONTROL PANEL – LOSS OF CONTROL VOLTAGE	Control power input signal low.	The control power input signal at I/O board TB3-81 was low for 1 second continuous. This signal is used to determine when the digital inputs are affected by a panel power loss versus an actual condition for their devices. This fault is not expected on an actual loss of microboard power, because the processor will be off before the fault delay.	The chiller will automatically restart when the cycling condition clears.	117
CONTROL PANEL – POWER FAILURE	Control power failure occurred (cycling version when displayed in orange).	A Control Power failure has occurred. This message can indicate a Cycling (auto-restart after power failure) or Safety (manual restart after power failure) shutdown, depending upon control center configuration. It indicates a cycling shutdown when displayed in orange characters; Safety shutdown when displayed in red characters.	If the power failure occurred while the chiller was running, it will automatically restart when power is restored. Auto-restart or manual restart is configured by a qualified Service Technician following instructions in YORK YMC2 Service Manual (Form 160.78-M2).	117
CONTROL PANEL – SCHEDULE	Chiller shut down by its programmed daily schedule.	The programmed Daily Schedule Setpoint has shutdown the chiller. If this occurs while the chiller is running, a Soft Shutdown is performed.	The chiller will automatically restart at the next scheduled start time.	117
EVAPORATOR – LOW PRESSURE	Evaporator (suction) pressure fell to the cycling shutdown threshold.	The evaporator pressure, as sensed by the evaporator transducer, has decreased to the shutdown threshold. For water cooling applications the shutdown threshold is a fixed value; for brine it varies with brine solution concentration and is programmed at the YORK factory (not to be changed except by a qualified Service Technician per Form 160.78-M2). Shutdown/reset thresholds (psig): R-134a 26.1 / 26.2 (water), 6.0–30.0 as programmed / 0.1 > shutdown threshold (brine); R-513A 30.2 / 30.2, 8.8–34.4 / 0.1 >; R-1234ze 15.4 / 15.5, 0.4–18.4 / 0.1 >; R-515B 15.2 / 15.3, 0.3–18.2 / 0.1 >.	The chiller will restart after the evaporator pressure increases to the restart threshold. If this shutdown occurs three times in a 90 minute period, an EVAPORATOR-LOW PRESSURE safety shutdown is initiated.	118
EXPANSION I/O – SERIAL COMMUNICATIONS	Communication between microboard and expansion I/O board lost.	Valid communication between the microboard and the LTC I/O Board have been disrupted for three consecutive attempts.	The chiller will automatically restart when valid communication is received.	118
LEAVING CHILLED LIQUID – LOW TEMPERATURE	Leaving chilled liquid fell to the programmed shutdown temperature.	The Leaving Chilled Liquid Temperature has decreased to the programmed Shutdown Temperature Setpoint. If the chiller is running when this occurs, a soft shutdown is performed.	The chiller will automatically restart when the temperature increases to the programmed Restart Temperature Setpoint.	118
MBC – HIGH AMPLIFIER TEMPERATURE	MBC amplifier board overtemperature (cycling level).	Set when the MBC amplifier temperature exceeds 140ºF (60ºC). Determined by the OptiView control software from temperature data transmitted through the serial comms.	Released when amplifier temperature drops 18ºF (10ºC) below the trip value.	118
MBC – HIGH DC/DC TEMPERATURE	MBC DC/DC converter board overtemperature (cycling level).	Set when the MBC DC/DC Converter board temperature exceeds 167ºF (75ºC). Determined by the OptiView control software from temperature data transmitted through the serial comms.	Released when DC/DC converter temperature drops 18ºF (10ºC) below the trip value.	118
MBC – SERIAL COMMUNICATIONS	Invalid or missing responses from the MBC over Modbus.	Set when an invalid or no response is received from the MBC to a Modbus command from the panel for eight successive requests (thresholds of consecutive timeouts, ID mismatches, checksum failures, or error packets). Becomes active during the Stopped State or MBC Startup State when the MBC initializes; stays active during Run and Soft Shutdown; becomes inactive at coastdown or stop when the DC Bus Voltage is less than 100 V.	Released when a valid response is received.	118
MBC SHUTDOWN – REQUESTING FAULT DATA	MBC shut the chiller down; cause not yet received over the serial link.	The MBC has shutdown the chiller and the control center has not yet received the cause of the fault from the MBC via the serial communications link. The MBC shuts down the chiller by opening the MBC Emergency Shutdown (ESD) contacts (located on the MBC control board and connected between TB6-15 and TB6-53 in the control center). Because serial communications are initiated every 2 seconds, this message appears for a few seconds.	Then replaced with one of the other MBC fault messages in this section.	118
MBC – SPEED SIGNAL FAULT	MBC lost the speed signal from the VSD during Rotation Mode.	Set when the MBC looses the speed signal that is expected from the VSD while the MBC is commanded in Rotation Mode. The MBC ESD Fault contacts open; the MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes. A 10 second bypass exists when the initial command to Rotation Mode occurs.	Released when the transmission is reestablished.	119
MBC – STARTUP FAILURE	Chiller failed to exit the MBC startup state within 60 seconds.	Set when the chiller fails to exit the MBC startup state within 60 seconds, during a chiller start.	Refer to YORK YMC2 Service Manual (Form 160.78-M2) for conditions necessary to complete MBC startup successfully. Check fault history details to determine which specific conditions were not met.	119
MBC – STOP (FAULT) CONTACTS OPEN	MBC ESD fault cause not received within 10 seconds.	See the previous MBC Shutdown – Requesting Fault Data message. If the control center’s microboard does not receive the cause of the MBC ESD fault over the serial link within 10 seconds after the ESD contacts open is recognized, it is assumed it is not forthcoming and that message is replaced with this message.	The chiller will automatically restart when the cycling condition clears.	119
MBC – V13 LOW FREQUENCY DISPLACEMENT	Excessive low-frequency shaft displacement at the impeller-end radial bearing, V axis.	The MBC has measured shaft displacement greater than 75 µm from center in the orthogonal radial axis designated V at the impeller end radial magnetic bearing during Levitation or Rotation mode over a 7 second window (approximately one-third of the air gap space to the touchdown bearing). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 75 µm.	119
MBC – V13 POSITION	Shaft displacement out of position at the impeller-end radial bearing, V axis.	The MBC has measured shaft displacement greater than 75 µm from center in the orthogonal radial axis designated V at the impeller end radial magnetic bearing during Levitation or Rotation mode (approximately half of the air gap space to the touchdown bearing). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 75 µm.	119
MBC – V24 LOW FREQUENCY DISPLACEMENT	Excessive low-frequency shaft displacement at the opposite-impeller-end radial bearing, V axis.	The MBC has measured shaft displacement greater than 75 µm from center in the orthogonal radial axis designated V at the opposite-impeller end radial magnetic bearing during Levitation or Rotation mode over a 7 second window (approximately 1/3 of the air gap space to the touchdown bearing). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 75 µm.	119
MBC – V24 POSITION	Shaft displacement out of position at the opposite-impeller-end radial bearing, V axis.	The MBC has measured shaft displacement greater than 75 µm from center in the orthogonal radial axis designated V at the opposite-impeller end radial magnetic bearing during Levitation or Rotation mode (approximately half of the air gap space to the touchdown bearing). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 75 µm.	119
MBC – W13 LOW FREQUENCY DISPLACEMENT	Excessive low-frequency shaft displacement at the impeller-end radial bearing, W axis.	The MBC has measured shaft displacement greater than 75 µm from center in the orthogonal radial axis designated W at the impeller end radial magnetic bearing during Levitation or Rotation mode over a 7 second window (approximately one-third of the air gap space to the touchdown bearing). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 75 µm.	119
MBC – W13 POSITION	Shaft displacement out of position at the impeller-end radial bearing, W axis.	The MBC has measured shaft displacement greater than 75 µm from center in the orthogonal radial axis designated W at the impeller end radial magnetic bearing during Levitation or Rotation mode (approximately half of the air gap space to the touchdown bearing). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 75 µm.	120
MBC – W24 LOW FREQUENCY DISPLACEMENT	Excessive low-frequency shaft displacement at the opposite-impeller-end radial bearing, W axis.	The MBC has measured shaft displacement greater than 75 µm from center in the orthogonal radial axis designated W at the opposite-impeller end radial magnetic bearing during Levitation or Rotation mode over a 7 second window (approximately one-third of the air gap space to the touchdown bearing). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 75 µm.	120
MBC – W24 POSITION	Shaft displacement out of position at the opposite-impeller-end radial bearing, W axis.	The MBC has measured shaft displacement greater than 75 µm from center in the orthogonal radial axis designated W at the opposite-impeller end radial magnetic bearing during Levitation or Rotation mode (approximately half of the air gap space to the touchdown bearing). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 75 µm.	120
MBC – VW13 VIBRATION	Synchronous shaft vibration above limit at the impeller-end radial bearing.	The MBC has measured synchronous speed (first harmonic) shaft vibration at the impeller end radial magnetic bearing greater than 60 µm from 0 to the peak amplitude in Rotation mode. Monitored only when the AVR and ABS filter is on, which occurs for speed above 80 Hz. The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when vibration is less than 60 µm.	120
MBC – VW24 VIBRATION	Synchronous shaft vibration above limit at the opposite-impeller-end radial bearing.	The MBC has measured synchronous speed (first harmonic) shaft vibration at the opposite-impeller end radial magnetic bearing greater than 60 µm from 0 to the peak amplitude in Rotation mode. Monitored only when the AVR and ABS filter is on, which occurs for speed above 80 Hz. The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when vibration is less than 60 µm.	120
MBC – Z12 LOW FREQUENCY DISPLACEMENT	Excessive axial shaft displacement over a 7-second window.	The MBC has measured shaft displacement greater than 100 µm axially from the design running position over a 7 second window (approximately 1/3 of the air gap space to the touchdown bearing axially). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 100 µm.	120
MBC – Z12 POSITION	Axial shaft displacement out of position.	The MBC has measured shaft displacement greater than 100 µm axially from the design running position (approximately 1/2 of the air gap space to the touchdown bearing axially). The MBC ESD Fault contacts open; the MBC remains in Levitation mode until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when displacement is less than 100 µm.	120
MULTIUNIT CYCLING – CONTACTS OPEN	External multi-unit cycling contacts opened.	The Multiunit Cycling contacts connected to I/O Board TB4-9 have opened to initiate a cycling shutdown. If the chiller is running when this occurs, the Pre-rotation Vanes are driven fully closed prior to shutting down the chiller.	The chiller will automatically restart when the contacts close.	120
SYSTEM CYCLING – CONTACTS OPEN	External system cycling contacts opened.	The System Cycling contacts connected to I/O Board TB4-13 have opened to initiate a cycling shutdown. If the chiller is running when this occurs, the Pre-rotation Vanes are driven fully closed prior to shutting down the chiller.	The chiller will automatically restart when the contacts close.	121
VSD – DC BUS PRE-REGULATION	DC link failed to reach the regulated setpoint after boost control was enabled.	The dc link voltage has not attained within ±50 V of the DC link voltage setpoint defined by the motor and line voltages (750 V for YMC2) within 2 seconds after the boost rectifier’s closed loop control has been enabled. The VSD logic board shall disable boost rectifier’s IGBT gating signals during this fault.	The VSD logic board shall time 10 seconds before clearing the fault and allowing another pre-charge to start; the VFD’s fan(s) and water pump(s) remain energized during this time. Up to three consecutive pre-charge-related or pre-regulation-related faults are allowed; after the third, Safety Shutdown message VSD – DC BUS PRE-REGULATION LOCKOUT is generated.	121
VSD – HIGH DC BUS VOLTAGE	DC link over-voltage.	The VSD’s DC link voltage is continuously monitored and if the level exceeds 878 VDC, ±28 VDC a Bus Over-Voltage shutdown is initiated. Look at the level of the 460 VAC applied to the drive; the specified voltage range is 414 VAC to 508 VAC.	If the incoming voltage is in excess of 508 VAC, steps should be taken to reduce the voltage to within the specified limits.	121
VSD – HIGH INTERNAL AMBIENT TEMPERATURE	VSD enclosure ambient overtemperature.	Generated when the higher of the two internal ambient temperature inputs exceeds a high limit of 158°F (70°C). Potential causes: internal VSD fan failure, VSD water pump failure, entering condenser water temperature higher than design, condenser water flow lower than required, fouled VSD heat exchanger, or restriction of condenser water to the VSD.	The unit’s fan(s) and water pump(s) remain energized until the internal temperature drops below 148°F (64°C), after which they shall be de-energized and the fault can be cleared.	121
VSD – HIGH PHASE A INPUT CURRENT	Input phase A instantaneous overcurrent.	Phase A input current exceeded the value listed for a given model of drive (490: 886 A; 0490A: 942 A; 744: 1446 A). The three input currents are monitored with Hall-effect current sensors, and their instantaneous values compared to the limit.	If three high input current cycling shutdown faults occur on any phase within 90 minutes, the third fault in the 90 minute period causes a Safety Shutdown; the chiller can then be restarted after the CLEAR FAULTS button is pressed.	121
VSD – HIGH PHASE B INPUT CURRENT	Input phase B instantaneous overcurrent.	See the previous VSD – HIGH PHASE A INPUT CURRENT message (limits: 490: 886 A; 0490A: 942 A; 744: 1446 A).	If three high input current cycling shutdown faults occur on any phase within 90 minutes, the third causes a Safety Shutdown; restart after the CLEAR FAULTS button is pressed.	121
VSD – HIGH PHASE C INPUT CURRENT	Input phase C instantaneous overcurrent.	See the previous VSD – HIGH PHASE A INPUT CURRENT message (limits: 490: 886 A; 0490A: 942 A; 744: 1446 A).	If three high input current cycling shutdown faults occur on any phase within 90 minutes, the third causes a Safety Shutdown; restart after the CLEAR FAULTS button is pressed.	121
VSD – HIGH PHASE A MOTOR CURRENT	Motor phase A instantaneous overcurrent.	Phase A motor current exceeded the value listed for a given model of drive (490, 0490A: 776 Amps; 744: 1086 Amps). The three motor currents are monitored with Hall-effect current sensors, and their instantaneous values compared to the limit.	If three high motor current cycling shutdown faults occur on any phase within 90 minutes, the third fault in the 90 minute period causes a Safety Shutdown; the chiller can then be restarted after the CLEAR FAULTS button is pressed.	121
VSD – HIGH PHASE B MOTOR CURRENT	Motor phase B instantaneous overcurrent.	See the previous VSD – HIGH PHASE A MOTOR CURRENT message (limits: 490, 0490A: 776 Amps; 744: 1086 Amps).	If three high motor current cycling shutdown faults occur on any phase within 90 minutes, the third causes a Safety Shutdown; restart after the CLEAR FAULTS button is pressed.	122
VSD – HIGH PHASE C MOTOR CURRENT	Motor phase C instantaneous overcurrent.	See the previous VSD – HIGH PHASE A MOTOR CURRENT message (limits: 490, 0490A: 776 Amps; 744: 1086 Amps).	If three high motor current cycling shutdown faults occur on any phase within 90 minutes, the third causes a Safety Shutdown; restart after the CLEAR FAULTS button is pressed.	122
VSD INITIALIZATION FAILED	VSD boards failed power-up initialization.	Upon application of power, all boards go through the initialization process. Causes of unsuccessful initialization: the control center and the VSD must be energized at the same time (pulling the fuse in the control center creates a problem; power-up must be accomplished by closing the main disconnect on the VSD cabinet with all fuses in place; a power interruption to the VSD Logic board will also generate this message); the Eproms must be of the correct version for each VSD board and installed correctly (created as a set, cannot be interchanged between earlier and later versions); serial data communications must be established (refer to VSD – Serial Communications fault).	Serial communications can be verified by selecting the VSD DETAILS screen from the MOTOR screen and observing the Full Load Amps value; a zero displayed for this and other VSD parameters indicates a serial communications link problem.	122
VSD – LOGIC BOARD POWER SUPPLY	VSD logic board low-voltage supplies out of limits.	Generated by the VSD logic board; indicates that the low voltage power supplies for the logic boards have dropped below their allowable operating limits. The supplies are derived from the secondary of the 120 VAC to 24 VAC transformer, which in turn is derived from the 480 VAC to 120 VAC control power transformer. This message usually means the power to the VSD has been removed.	The chiller will automatically restart when the cycling condition clears.	122
VSD – LOGIC BOARD PROCESSOR	Communication failure between the two VSD logic board microprocessors.	Generated if a communications problem occurs between the two microprocessors on the VSD Logic Board.	The chiller will automatically restart when the cycling condition clears.	122
VSD – LOW DC BUS VOLTAGE	DC link under-voltage after successful pre-charge.	Following a successful DC-link pre-charge and pre-regulation, the DC-link under-voltage shutdown is generated when the dc link voltage falls below the trip level for 10 ms. The trip level is set to 720 VDC (30 VDC below the calculated DC link voltage setpoint of 750 VDC for both 60 Hz and 50 Hz units).	The chiller will automatically restart when the cycling condition clears.	122
VSD – LOW PHASE A INPUT BASEPLATE TEMPERATURE	Input rectifier phase A IGBT module too cold.	The temperature of the IGBT module of the input rectifier’s phase A has decreased below the low limit of 37°F (2.7°C).	All phase temperatures have to increase above the fault-reset threshold of 42°F (5.5°C) for this fault to be cleared.	122
VSD – LOW PHASE B INPUT BASEPLATE TEMPERATURE	Input rectifier phase B IGBT module too cold.	See the previous VSD – LOW PHASE A INPUT BASEPLATE TEMPERATURE message.	All phase temperatures have to increase above the fault-reset threshold of 42°F (5.5°C) for this fault to be cleared.	122
VSD – LOW PHASE C INPUT BASEPLATE TEMPERATURE	Input rectifier phase C IGBT module too cold.	See the previous VSD – LOW PHASE A INPUT BASEPLATE TEMPERATURE message.	All phase temperatures have to increase above the fault-reset threshold of 42°F (5.5°C) for this fault to be cleared.	122
VSD – LOW PHASE A MOTOR BASEPLATE TEMPERATURE	Inverter phase A IGBT module too cold.	The temperature of the IGBT module of the inverter’s phase A has decreased below the low limit of 37°F (2.7°C).	All phase temperatures have to increase above the fault-reset threshold of 42°F (5.5°C) for this fault to be cleared.	122
VSD – LOW PHASE B MOTOR BASEPLATE TEMPERATURE	Inverter phase B IGBT module too cold.	See the previous VSD – LOW PHASE A MOTOR BASEPLATE TEMPERATURE message.	All phase temperatures have to increase above the fault-reset threshold of 42°F (5.5°C) for this fault to be cleared.	122
VSD – LOW PHASE C MOTOR BASEPLATE TEMPERATURE	Inverter phase C IGBT module too cold.	See the previous VSD – LOW PHASE A MOTOR BASEPLATE TEMPERATURE message.	All phase temperatures have to increase above the fault-reset threshold of 42°F (5.5°C) for this fault to be cleared.	122
VSD – NOT RUNNING	VSD not reporting run state while a run command is issued.	The VSD has not reported run state via serial communications for 8 seconds while the microboard issues a VSD run command.	The fault is released when the microboard command is Stopped State.	122
VSD – PHASE A INPUT DCCT OFFSET	Input DCCT offset out of range at pre-charge initiation.	Upon the assertion of a precharge command, the output voltage of each of the DCCTs which sense the input current will be monitored. The first value of each output voltage is compared against an offset threshold level of ±24.4 mV; if this threshold level is not exceeded, an average of eight readings on each DCCT output is taken and used for DCCT offset compensation. If the offset threshold at initialization exceeded this threshold, this shutdown is generated.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PHASE B INPUT DCCT OFFSET	Input DCCT offset out of range at pre-charge initiation.	See the previous VSD – PHASE A INPUT DCCT OFFSET message.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PHASE C INPUT DCCT OFFSET	Input DCCT offset out of range at pre-charge initiation.	See the previous VSD – PHASE A INPUT DCCT OFFSET message.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PHASE A INPUT GATE DRIVER	Boost rectifier phase A gate driver fault.	The VSD boost rectifier’s IGBT gate driver boards monitor their power supply voltages, as well as the saturation voltage drop across each main IGBT while turned on. If a voltage on the Phase A boost rectifier IGBT gate driver board falls out of the prescribed limit, the gate driver board shall turn the rectifier’s IGBTs off and send this shutdown.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PHASE B INPUT GATE DRIVER	Boost rectifier phase B gate driver fault.	See the previous VSD – PHASE A INPUT GATE DRIVER message.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PHASE C INPUT GATE DRIVER	Boost rectifier phase C gate driver fault.	See the previous VSD – PHASE A INPUT GATE DRIVER message.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PHASE A MOTOR GATE DRIVER	Inverter phase A gate driver fault.	The VSD inverter’s IGBT gate driver boards monitor their power supply voltages, as well as the saturation voltage drop across each IGBT while turned on. If a voltage on the Phase A gate driver board exceeds the prescribed limit, the gate driver board shall turn the inverter’s IGBTs off and send this shutdown.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PHASE B MOTOR GATE DRIVER	Inverter phase B gate driver fault.	See the previous VSD – PHASE A MOTOR GATE DRIVER message.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PHASE C MOTOR GATE DRIVER	Inverter phase C gate driver fault.	See the previous VSD – PHASE A MOTOR GATE DRIVER message.	The chiller will automatically restart when the cycling condition clears.	123
VSD – PRECHARGE – LOW DC BUS VOLTAGE 1	DC bus did not reach the low pre-charge threshold in time.	During pre-charge, the DC-link voltage must reach at least the low threshold, which is determined by Line Voltage Setpoint (460 V: 50 V; 380/415 V: 41 V; 230 V: 25 V) within 4 seconds after the pre-charge signal has been commanded. If this condition is not met, this shutdown is generated.	The VSD logic board shall time 10 seconds before clearing the fault and allowing another pre-charge to start; the VFD’s fan(s) and water pump(s) remain energized during this time. Up to three consecutive pre-charge-related faults are allowed; after the third, Safety Shutdown message VSD – PRECHARGE LOCKOUT is generated.	123
VSD – PRECHARGE – LOW DC BUS VOLTAGE 2	DC bus did not reach the high pre-charge threshold in time.	During Pre-charge, the DC-link voltage must reach at least the high threshold which is determined by Line Voltage Setpoint (460 V: 500 V; 380/415 V: 414 V; 230 V: 250 V) within 15 seconds after the pre-charge signal has been commanded. If this condition is not met, this shutdown is generated.	The VSD logic board shall time 10 seconds before clearing the fault and allowing another pre-charge to start; the VFD’s fan(s) and water pump(s) remain energized during this time. Up to three consecutive pre-charge-related faults are allowed; after the third, Safety Shutdown message VSD – PRECHARGE LOCKOUT is generated.	123
VSD – RUN SIGNAL	Redundant run commands not both received within 5 seconds.	Redundant RUN signals are generated by the control center; one via TB6-24 and the second via the Serial Communications link. Upon receipt of either of the two RUN commands by the VSD, a 5 second timer shall commence timing. If both run commands are not received by the VSD Logic Board within 5 seconds, a shutdown is performed. Generally indicative of a wiring problem between the control center and the VSD.	The chiller will automatically restart when the cycling condition clears.	124
VSD – SERIAL COMMUNICATIONS	No response from the VSD logic board over three consecutive attempts.	Generated by OptiView when communications between the control center Microboard and the VSD Logic Board causes no response over three attempts consecutively. Generally indicative of defective wiring between 2TB on the VSD Logic Board and the Microboard J13.	The chiller will automatically restart when the cycling condition clears.	124
VSD – SERIAL RECEIVE	VSD not receiving valid communication from the control panel.	The VSD logic board does not receive valid communication from the control panel for 10 consecutive seconds.	The chiller will automatically restart when the cycling condition clears.	124
VSD SHUTDOWN – REQUESTING FAULT DATA	VSD shut the chiller down; cause not yet received over the serial link.	The VSD has shutdown the chiller and the control center has not yet received the cause of the fault from the VSD, via the serial communications link. The VSD shuts down the chiller by opening the Motor Controller VSD Stop Contacts (located on the VSD Logic Board and connected between TB6-16 and TB6-53 in the control center). Because serial communications are initiated every 2 seconds, this message appears for a few seconds.	Then replaced with one of the other VSD fault messages.	124
VSD – SINGLE PHASE INPUT POWER	One line-to-line input voltage fell below 200 Vrms.	The VSD monitors the RMS value of each of the three line-to-line voltages on a cycle-by-cycle basis. If the RMS value of any one of the three line-to-line voltages falls below 200 Vrms in any one cycle, this shutdown is generated.	The chiller will automatically restart when the cycling condition clears.	124
VSD – STOP (FAULT) CONTACTS OPEN	VSD fault cause not received within 20 seconds.	See the previous VSD Shutdown – Requesting Fault Data message. If the control center’s microboard does not receive the cause of the fault over the Serial Link within 20 seconds, it is assumed it is not forthcoming and that message is replaced with VSD STOP CONTACTS OPEN message.	The chiller will automatically restart when the cycling condition clears.	124

Safety shutdown messages

Code / display	Meaning	Cause	Action	Page
AUXILIARY SAFETY – CONTACTS CLOSED	User-defined auxiliary safety input tripped.	The Auxiliary Safety shutdown input, connected to I/O Board TB4-31 senses 115 VAC, initiating a safety shutdown. This input is a general-purpose, user-defined safety shutdown input.	The chiller can be started after the contacts open and the CLEAR FAULT button is pressed.	125
CONDENSER – HIGH PRESSURE CONTACTS OPEN	Electromechanical high pressure safety switch tripped.	The contacts of the electromechanical high pressure safety device, located on the condenser shell, have opened because this device has detected a pressure greater than 204±7 psig. The contacts will automatically close when the condenser pressure decreases to is less than 160±10 psig.	The chiller can be started after the contacts close and the CLEAR FAULT button is pressed.	125
CONDENSER – PRESSURE TRANSDUCER OUT OF RANGE	Condenser pressure transducer signal outside its valid range.	The Condenser Pressure Transducer indicates a pressure that is less than 6.8 psig or greater than 300.0 psig. This is outside the normal operating range of the transducer. This generally indicates a defective transducer.	The chiller can be started after the transducer is indicating a pressure that is within range and the CLEAR FAULT button is pressed.	125
CONTROL PANEL – POWER FAILURE	Control power failure (safety version when displayed in red).	A Control Power failure has occurred. This message can indicate a Cycling (auto-restart after power failure) or Safety (manual restart after power failure) shutdown, depending upon control center configuration. It indicates a cycling shutdown when displayed in orange characters; Safety shutdown when displayed in red characters.	If the power failure occurred while the chiller was running, it will automatically restart when power is restored. Auto-restart or manual restart is configured by a qualified Service Technician following instructions in YORK YMC2 Service Manual (Form 160.78-M2).	125
DISCHARGE – LOW TEMPERATURE	Discharge temperature below 30°F.	The discharge temperature, as sensed by the Discharge Temperature Thermistor, has decreased to less than 30.0°F (-1.1°C).	The chiller can be started after the temperature increases to greater than 30.0°F (-1.1°C) and the CLEAR FAULT button is pressed.	125
EVAPORATOR – LOW PRESSURE	Third evaporator low-pressure cycling shutdown within 90 minutes.	The evaporator pressure, as sensed by the Evaporator Transducer, has decreased to the shutdown threshold and caused cycling shutdown three times in a 90 minute period. For water cooling applications the shutdown threshold is a fixed value; for Brine cooling applications it varies according to the concentration of the Brine solution and is programmed at the YORK Factory (not to be changed except by a qualified Service Technician per Form 160.78-M2). Shutdown/reset thresholds (psig): R-134a 26.1 / 26.2 (water), 6.0–30.0 as programmed / 0.1 > shutdown threshold (brine); R-513A 30.2 / 30.2, 8.8–34.4 / 0.1 >; R-1234ze 15.4 / 15.5, 0.4–18.4 / 0.1 >; R-515B 15.2 / 15.3, 0.3–18.2 / 0.1 >.	The chiller can be started after the evaporator pressure increases to the restart threshold and the CLEAR FAULT button is pressed.	126
EVAPORATOR – LOW PRESSURE – SMART FREEZE	Smart Freeze protection timed out with the evaporator below the freeze threshold.	Smart Freeze protection is activated and has shutdown the chiller because the evaporator temperature has been below the Smart Freeze threshold for greater than the allowable number of seconds. If sensor RT7 is Enabled the freeze threshold is 32.8°F (0.4°C); if RT7 is not enabled the evaporator refrigerant temperature used is the Evaporator Saturation Temperature and the freeze threshold is 34.0°F (1.1°C). The total count is incremented once for every second the evaporator refrigerant temperature is below the freeze threshold; # seconds to freezing = (4053.7) / (freeze threshold – evap. refrigerant temp.). Smart Freeze is activated only if the feature has been enabled by a Service technician and the Leaving Chilled Liquid temperature Setpoint is less than 38.0°F (3.3°C).		126
EVAPORATOR – TRANSDUCER OR LEAVING LIQUID PROBE	Evaporator pressure and leaving chilled liquid readings inconsistent — probable transducer or thermistor defect.	A possible defective Evaporator pressure Transducer or Leaving Chilled Liquid temperature Thermistor has been detected. The control center converts the evaporator pressure to a Saturated Temperature value and compares it to the Leaving Chilled Liquid temperature; the difference should not be outside the range of 2.5°F (1.4°C) to 25.0°F (13.9°C). To initiate a shutdown, the difference must be outside the acceptable range continuously for 10 minutes.	The chiller can be started after the CLEAR FAULT button is pressed.	126
EVAPORATOR – TRANSDUCER OR TEMPERATURE SENSOR	Evaporator pressure and refrigerant temperature readings inconsistent — probable sensor defect.	A possible defective Evaporator pressure Transducer or Refrigerant Temperature Sensor has been detected. The difference between the evaporator saturated temperature and the optional Evaporator Refrigerant Temperature Sensor greater than 3.0°F (1.7°C), continuously for 1 minute, performs this shutdown. Check performed only if: chiller running at least 10 minutes; RT7 enabled by a Service technician; NOT in Brine cooling mode; Smart Freeze is enabled; and RT7 or Evaporator Saturation Temperature indicating less than 32.0°F (0°C).	The chiller can be started after the temperatures are within 3.0°F (1.7°C) of one another and the CLEAR FAULT button is pressed.	127
MBC – CABLE FAULT	Supervisory jumper continuity lost in a main cable assembly.	Set when the MBC does not detect continuity expected through a set of supervisory pins through an embedded jumper in either of the two main electrical cable assemblies. The MBC ESD Fault contacts open; the MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the connector to cable supervisory jumper continuity is restored. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	127
MBC – CUSTOMER SERIAL LINK DISABLED	MBC serial setting changed away from panel control.	Set when the MBC Local/Remote Modbus command is not reported from the MBC as set for panel control. This would be caused if the MBC were accessed via a computer using diagnostic software and the serial communication setting then changed in the Remote Command tab from Customer Serial Link to another choice.	The chiller can be started when the MBC setting is restored to Customer Serial Link using the diagnostic software according to Form 160.78-M1 and the OptiView panel CLEAR FAULTS button is pressed.	127
MBC – DATA ACQUISITION FAULT	Internal communication problem on the AMB control board.	Set when the MBC detects an internal communication problem on the AMB control board. The MBC ESD Fault contacts open; the MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the MBC recognizes proper internal communication after a reboot. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULT button is pressed.	127
MBC – DSP COMMUNICATION	Communication error across circuit boards in the MBC.	Set when the MBC control board detects a communication error across circuit boards in the MBC. The MBC ESD Fault contacts open; the MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the board-level communication failure is resolved. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	127
MBC – DSP INITIALIZATION	MBC control board software failed to initialize.	Set when the MBC control board software fails to initialize. The MBC is determining software parameters are not correct. The MBC ESD Fault contacts open; the MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	The condition may require reloading the control parameters to the control. Released on a successful re-boot. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	127
MBC – DSP INTEGRITY	Internal problem on the AMB control board.	Set when an internal problem occurs on the AMB control board. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the board-level communication failure is resolved. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	128
MBC – DSP WATCHDOG	Lapse in MBC microprocessor activity detected by the watchdog.	Set when the MBC determines a lapse in internal microprocessor activity through its Watchdog device. The MBC Watchdog Fault contacts open. The MBC will not react to a levitation mode change command via serial comms and remains in the levitation mode it was in when the fault occurred until power is removed; power is automatically removed when the VSD is stopped and the precharge command ceases so the DS bus, which powers the MBC, depletes.	The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	128
MBC – EEPROM	Data discrepancy with the EPROM on the AMB control board.	Set when a data discrepancy occurs with the EPROM on the AMB control board. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the board-level communication failure is resolved. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	128
MBC – EXCESSIVE SHUTDOWNS	Three MBC cycling shutdowns within 15 minutes.	Set if three MBC Cycling Shutdowns occur in a 15 minute window. The 15 minute window begins with the first MBC fault.	Released when all MBC faults clear. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	128
MBC – FLASH MEMORY CLEAR	Internal problem with the memory chip on the AMB control board.	Set when an internal problem occurs with the memory chip on the AMB control board. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the board-level communication failure is resolved. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	128
MBC – FLASH MEMORY WRITE	Internal problem with the memory chip on the AMB control board.	Set when an internal problem occurs with the memory chip on the AMB control board. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the board-level communication failure is resolved. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	128
MBC – HIGH AMPLIFIER TEMPERATURE	MBC amplifier overtemperature (safety level).	Set when the MBC amplifier temperature exceeds 176ºF (80ºC) for 2 seconds continuous. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until the VSD rotation signal indicates less than 10 Hz; then the MBC de-levitates the rotor.	Released when amplifier temperature drops 5.4ºF (3.0ºC) below the trip value. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	128
MBC – HIGH BEARING CURRENT	Magnetic bearing excitation current above the power amplifier rating.	Set when the MBC has determined any of the driveline Magnetic Bearing excitation currents exceeds the maximum Power Amplifier rating, programmed at 4 A, for 10 seconds continuous. The MBC ESD Fault contacts open. The MBC remains in Levitation mode attempting to keep the motor shaft levitated until the VSD rotation signal indicates greater than 10 Hz.	Released when all of the bearing currents are less than 4 A. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	128
MBC – HIGH BEARING Z1 TEMPERATURE	Impeller-end axial bearing overtemperature.	Set when the MBC detects a temperature greater than 266ºF (130ºC) on the impeller end axial magnetic bearing. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until the VSD rotation signal indicates is less than 10 Hz.	Released when temperature is less than 266ºF (130ºC). The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	129
MBC – HIGH BEARING Z2 TEMPERATURE	Opposite-impeller-end axial bearing overtemperature.	Set when the MBC detects a temperature greater than 266ºF (130ºC) on the opposite-impeller end axial magnetic bearing. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until the VSD rotation signal indicates is less than 10 Hz.	Released when temperature is less than 266ºF (130ºC). The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	129
MBC – HIGH DC/DC TEMPERATURE	MBC DC/DC converter overtemperature (safety level).	Set when the MBC DC/DC Converter board temperature exceeds 203ºF (95ºC) for 2 seconds continuous. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until the VSD rotation signal indicates is less than 10 Hz; then the MBC de-levitates the rotor.	Released when the DC/DC converter temperature drops 5.4ºF (3ºC) below the trip value. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	129
MBC – NO LEVITATION	Levitation commanded but the Rotation Allowed input is not high.	Set when OptiView software is commanding MBC Levitation Mode ON but the Rotation Allowed digital input from the MBC contacts is not reading high. This fault is inhibited if no VSD DC Bus Voltage is present and during the first 15 seconds after the Levitation Mode ON command is sent.	Released when the chiller is stopped. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	129
MBC – OSCILLATOR FAULT	Position sensor oscillator overloaded.	Set when the MBC has determined either the radial or axial position sensor internal Oscillator, which drives the position sensor coils, is overloaded for 1 second continuous. This is a result of an open or short in the connection to the shaft position sensors or a failure on the board. LED V1 or V2 illuminated on the oscillator board indicates a failure with radial position or elongation channels; LED V3 or V4 illuminated indicates a failure with the axial position. The MBC ESD Fault contacts open.	Released when the Oscillator voltage drop is normal. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	129
MBC – OVERSPEED FAULT	Rotor speed above the 458 Hz setpoint.	Set when the MBC determines the rotor speed exceeds the programmed setpoint of 458 Hz for 0.1 seconds continuous. Rotor speed is transmitted to the MBC from the VSD. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the speed signal no longer exceeds the setpoint, which should occur when the chiller is stopped. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	129
MBC – POWER SUPPLY FAULT	Power supply board overload or abnormal DC/DC converter voltage.	Set when the MBC detects overload on the Wide Input Range power supply board or indicates abnormal voltage at the DC/DC converter. The Wide Input Range power supply board overload is detected by monitoring temperature at the transformer. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when voltage is restored. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	129
MBC – ROTOR ELONGATION	Axial displacement difference above the interpolated limit.	Set when the MBC has calculated the algebraic difference between the displacement at shaft impeller end axial position sensor and the shaft opposite-impeller end axial position sensor is greater than the value calculated by linear interpolation between 300 µm at 436 Hz to 350 µm at zero Hz. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the difference in displacements no longer exceeds these values. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	130
MBC – SPEED SIGNAL FAULT	Third MBC speed signal cycling fault within 90 minutes.	Set when the MBC has the speed signal cycling fault three times in a 90-minute window. The window is started when not currently in a window and a MBC Speed Signal cycling fault is received. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC buss power depletes.	Released when the transmission is reestablished. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	130
SAFETY STOP	Panel safety stop pushbutton depressed.	Set when the panel safety stop hardware pushbutton is depressed, removing input from the I/O Board terminal TB3-28 for >500 msec. continuous. It also sets the local command to STOP.	The chiller can be started when the pushbutton is released and the OptiView panel CLEAR FAULTS button is pressed.	130
MBC – STARTUP FAILURE	Third MBC startup failure within 90 minutes.	Set when the chiller initiates three MBC-STARTUP FAILURE Cycling Shutdown in a 90 minute period.	Refer to YORK YMC2 Service Manual (Form 160.78-M2) for conditions necessary to complete MBC startup successfully. Check fault history details to determine which specific conditions were not met.	130
MBC – UNAUTHORIZED ROTATION	Rotor speed signal present while Levitation Mode is not activated.	Set when the MBC detects a rotor speed signal from the VSD while the Levitation Mode is not activated. The MBC ESD Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms or VSD DC bus power depletes.	Released when the MBC Levitation or Rotation mode is activated or the VSD speed signal indicates no shaft rotation. The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	130
MOTOR – HIGH WINDING TEMPERATURE	Motor winding temperature above the shutdown threshold.	Occurs when either of the following conditions are present: any of the enabled motor winding temperatures exceeded the programmed High Winding Temperature Shutdown Threshold of 302˚F (150˚C); or the Average Winding Temperature has exceeded the programmed High Winding Temperature Shutdown threshold for 3 continuous seconds.	The chiller can be started after all winding temperatures decreased to at least 18˚F (10˚C) below the shutdown threshold and the COMPRESSOR is stopped. The safety shutdown will not act on any individual winding temperature sensor that has been disabled with the TEMPERATURE DISABLE Setpoint on the Motor Details Screen.	130
MOTOR – HIGH HOUSING TEMPERATURE	Motor housing temperature at or above 185°F.	Set when Motor Housing Temperature is greater than or equal to 185°F (85°C).	Fault is released when Motor Housing Temperature is less than 158°F (70°C). The chiller can be started when the condition is released and the OptiView panel CLEAR FAULTS button is pressed.	130
SALES ORDER - INVALID COMPRESSOR MODEL	Compressor Model field does not conform to the required format.	Set when the Compressor Model field entered on the Setpoints – Setup – Sales Order screen does not conform to the format expected (data found on the compressor nameplate). Initiated if any of the following are true: MOTOR is anything other than M1; MOTOR REV is anything other than ‘B’; character other than ‘-‘ between position 3 and 4; SS/LS IMP DIAM is anything other than 164, 174, 186, 197 or 205; SS/LS ROTATION is anything other than ‘F’; SS/LS IMP REV is anything other than a character ‘A’ through ‘Z’; SS/LS FLOW REV is anything other than a character ‘A’ through ‘B’.	The fault released when none of the above statements are true. Then the CLEAR FAULTS button on the Home screen can be pressed and the chiller started.	131
SURGE PROTECTION – EXCESS SURGE	Surge count exceeded the limit with shutdown enabled.	(Applies only if Surge Protection SHUTDOWN feature is Enabled.) The Surge Window Count surge events exceeded the Count Limit setpoint. The chiller shuts down as soon as the count exceeds the limit.	The chiller can be started after the CLEAR FAULT button is pressed.	131
WATCHDOG – SOFTWARE REBOOT	Microboard software watchdog reset the processor.	The Microboard’s software Watchdog initiated a Microprocessor reset because it detected that a portion of the chiller operating Program was not being executed. The result of this reset is a Safety shutdown and re-initialization of the Program. Generally indicative of a severe electrical power disturbance or impending Microboard Failure.	The chiller can be started after the COMPRESSOR switch is placed in the Stop-Reset (O) position.	131
VSD – DC BUS LOCKOUT – DO NOT CYCLE POWER	DC bus voltage present while the unit is stopped with no energize command.	When the unit is stopped in a mode where no command exists to energize the DC bus, the DC bus voltage is monitored and checked against a threshold level of 50V every five minutes. If the DC bus voltage is higher than the threshold value, this shutdown is generated.	When the condition clears and VSD input modules tested and determined acceptable the chiller can be started after the CLEAR FAULTS button is pressed.	131
VSD – DC BUS PRE-REGULATION LOCKOUT	Third consecutive pre-charge/pre-regulation fault.	If the unit fails to complete pre-regulation due to VSD – DC BUS PRE-REGULATION fault, it must repeat pre-charge in order to attempt another pre-regulation. The VSD logic board waits 10 seconds before clearing the DC-link voltage pre-regulation fault and allowing another pre-charge to start; the unit’s fan(s) and water pump(s) remain energized during this wait time. Up to three consecutive pre-charge-related or pre-regulation-related faults are allowed; after the third consecutive fault, this shutdown is generated. The VSD logic board disables boost rectifier’s IGBT gating signals if the third fault occurred during pre-regulation.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	131
VSD – GROUND FAULT	Ground fault current above the shutdown value.	Generated when the sum of the three phases of instantaneous input current values are greater than the shutdown value for a period of 1 second for the given model of drive (490, 0490A: 40 Amps; 744: 120 Amps).	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	132
VSD – HIGH PHASE A INPUT BASEPLATE TEMPERATURE	Input rectifier phase A baseplate overtemperature.	The Input Baseplate Temperature exceeded the shutdown value for the given model of drive (490, 0490A: 190°F / 87.8°C; 744: 170°F / 76.6°C). After the unit trips, the VSD fan(s) and water pump(s) shall remain energized until the temperatures of all three rectifier’s phases drop below the fault-reset threshold of 165°F (73.8°C). In April of 2016 the shutdown control for the fan(s) and pump(s) was changed to keep the fan(s) and pump(s) running for 2 minutes after the fault occurred (software version C.HYP.03.04.01, and C.HYP.04.04.01); when this happens, the unit’s fan(s) and water pumps shall be de-energized.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	132
VSD – HIGH PHASE B INPUT BASEPLATE TEMPERATURE	Input rectifier phase B baseplate overtemperature.	See the previous VSD – HIGH PHASE A INPUT BASEPLATE TEMPERATURE message.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	132
VSD – HIGH PHASE C INPUT BASEPLATE TEMPERATURE	Input rectifier phase C baseplate overtemperature.	See the previous VSD – HIGH PHASE A INPUT BASEPLATE TEMPERATURE message.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	132
VSD – HIGH PHASE A MOTOR BASEPLATE TEMPERATURE	Motor baseplate overtemperature (phase A).	The chiller has shutdown because the motor baseplate temperature exceeded the high limit of 190°F (87.7°C). After the unit trips, the VSD fan(s) and water pump(s) shall remain energized until the motor baseplate temperatures of all phases drop below the fault-reset threshold of 165°F (73.8°C). In April of 2016 the shutdown control for the fan(s) and pump(s) was changed to keep the fan(s) and pump(s) running for 2 minutes after the fault occurred (software version C.HYP.03.04.01, and C.HYP.04.04.01); when this happens, the unit’s fan(s) and water pump(s) shall be de-energized.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	132
VSD – HIGH PHASE B MOTOR BASEPLATE TEMPERATURE	Motor baseplate overtemperature (phase B).	See the previous VSD – HIGH PHASE A MOTOR BASEPLATE TEMPERATURE message.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	132
VSD – HIGH PHASE C MOTOR BASEPLATE TEMPERATURE	Motor baseplate overtemperature (phase C).	See the previous VSD – HIGH PHASE A MOTOR BASEPLATE TEMPERATURE message.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	132
VSD – HIGH TOTAL DEMAND DISTORTION	Input current TDD above 25%.	Indicates the input current to the VSD is not sinusoidal. Occurs if the TDD exceeds 25% continuously for 45 seconds. TDD (Total Demand Distortion) is defined by IEEE Std 519-1992 as the total root-sum-square harmonic current distortion, in percent of the maximum demand load current (15 or 30 min demand). The displayed TDD is the total RMS value of all the harmonic current supplied by the main power to the VSD divided by the chiller Full Load Amps, in percent.	The chiller can be started after the CLEAR FAULT button is pressed.	132
VSD – INVERTER PROGRAM FAULT	Inverter internal code exception.	When some internal code exception of Inverter happens such as divide-by-zero, out-of-range parameter, for example, the unit shall trip and the HYP logic board shall indicate the inverter program fault and the error information including module number and line number via the communications link.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	132
VSD – INPUT CURRENT OVERLOAD	Input RMS current above the 116.7% threshold for 10 seconds.	The highest of the three input RMS currents is monitored and compared against 105% of the job input current at 90% line voltage. Because the job input current setting is at nominal line voltage and this fault is based on power, and accounts for low-tolerance line voltage, its threshold is 105%/90%=116.7%. If this value is exceeded continuously for 10 seconds, this shutdown is generated. The 10 s timer is reset if three consecutive RMS current values fall below the overload threshold.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	133
VSD – INPUT DCCT OFFSET LOCKOUT	Three consecutive input DCCT offset cycling faults.	If three consecutive VSD – Phase A, B or C Input DCCT Offset cycling faults occur, this safety shutdown is generated to require investigation and manual reset.	When the condition clears and VSD input modules determined acceptable, the chiller can be started after the CLEAR FAULTS button is pressed.	133
VSD – LOGIC BOARD PLUG	Rectifier or inverter DCCT plug not installed.	A jumper is located in the rectifier and inverter DCCT plugs to feedback a digital signal to indicate if the plugs are installed or not. If either plug is not installed, a low value is read on the digital input causing the unit to trip, and this shutdown is generated.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	133
VSD – MOTOR CURRENT IMBALANCE	Motor phase current imbalance above 30%.	The three phase compressor motor current imbalance was greater than 30% continuously for 45 seconds. The imbalance is not checked until the chiller has been running for at least 45 seconds and the average of the three phases of motor current is greater than 80% of the programmed 100% chiller Full Load Amps. The Variable Speed Drive detects the unbalance condition and advise the OptiView Control Center Microboard via serial communications.	The chiller can be started after the CLEAR faults button is pressed.	133
VSD – 105% MOTOR CURRENT OVERLOAD	Motor RMS current above 105% of the 525 A limit for 40 seconds.	The highest of the three motor RMS currents is monitored and compared against 105% of the motor current limit of 525 A. If this value is exceeded continuously for 40 seconds, this shutdown is generated. The 40 second timer shall reset if three consecutive RMS current values fall below the overload threshold.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	133
VSD – MOTOR CURRENT THD FAULT	Motor current THD above limit.	Motor current (inverter output) total harmonic distortion (THD) level is exceed. The fault is based on a fixed value of measured harmonic current from the inverter.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	133
VSD – PHASE A INPUT DCCT	Input phase A current below the minimum during precharge.	The input current in each phase to the VSD is measured during the precharge time. If the input current does not exceed the shutdown value for the given model of drive (0490A, 490: 5.0 amps; 744: 15.0 amps), then this shutdown is generated.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	133
VSD – PHASE B INPUT DCCT	Input phase B current below the minimum during precharge.	See the previous VSD –PHASE A INPUT DCCT message.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	133
VSD – PHASE C INPUT DCCT	Input phase C current below the minimum during precharge.	See the previous VSD –PHASE A INPUT DCCT message.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	133
VSD – PHASE A MOTOR DCCT	Motor phase A DCCT cable/current check failed.	This shutdown determines if the cable at the motor DCCT is connected. This shutdown is generated 1.5 seconds after the motor run command if the motor current does not exceed 25 A.		133
VSD – PHASE B MOTOR DCCT	Motor phase B DCCT cable/current check failed.	See the previous VSD –PHASE A MOTOR DCCT message.		133
VSD – PHASE C MOTOR DCCT	Motor phase C DCCT cable/current check failed.	See the previous VSD –PHASE A MOTOR DCCT message.		133
VSD – PRECHARGE LOCKOUT	Third consecutive pre-charge fault.	If the unit fails to complete pre-charge (due to VSD – PRECHARGE – LOW DC BUS VOLTAGE or VSD – PRECHARGE – HIGH DC BUS VOLTAGE), the VSD logic board shall time 10 seconds before clearing the fault and allowing another pre-charge to start. The unit’s fan(s) and water pump(s) shall remain energized during this time. The VSD logic board shall allow up to three consecutive pre-charge-related faults to occur. After the third consecutive pre-charge-related fault, this shutdown is generated.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	134
VSD – RECTIFIER PROGRAM FAULT	Rectifier internal code exception.	When some internal code exception of Rectifier happens such as divide-by-zero, out-of-range parameter, for example, the unit shall trip and the HYP Logic Board shall indicate the rectifier program fault and the error information including module number and line number via the communications link.	When the condition clears, the chiller can be started after the CLEAR FAULTS button is pressed.	134
VSD SHUTDOWN – REQUESTING FAULT DATA	VSD shut the chiller down; cause not yet received over the serial link (safety).	The VSD has shut down the chiller and the control center has not yet received the cause of the fault from the VSD, via the serial communications link. The VSD shuts down the chiller by opening the Motor Controller VSD Stop Contacts (located on the VSD Logic Board and connected between TB6-16 and TB6-53 in the control center). Since serial communications are initiated every 2 seconds, this message appears for a few seconds.	Then replaced with one of the other VSD fault messages.	134
VSD - INVERTER PROGRAM FAULT	Inverter software/motor design validation failed.	This drive will be used on two different motor designs. It is necessary to validate that the inverter software is correct for the motor designed used in the application. To ensure that the correct software is installed in the VSD logic board, three pieces of data must state that the correct inverter software is installed in the VSDF logic board for this shutdown not to occur. The software in the VSD logic board U38, must match the condition on J2 pin 14 and the programmed motor selection from the chiller control center.		134
VSD - LINE VOLTAGE PHASE LOCK LOOP	Drive cannot determine the input voltage frequency (50/60 Hz).	The drive will automatically determine the input voltage frequency. The information about the input voltage frequency is provided to the drive logic board by the line voltage isolation board. If the driver logic board cannot determine that the input voltage frequency is 50 Hz or 60 Hz then this shutdown will occur.		134
VSD - LINE VOLTAGE PHASE ROTATION	Internal phase rotation determinations disagree.	The input of the drive is not sensitive to the phase rotation of the input voltage, but internally to the drive the rotation must remain the same. The output of the line voltage isolation board cannot shown CBA rotation when the input voltage to the drive is really ABC rotation. There are two methods within the VSD logic board to determine the line voltage phase rotation. If these two methods do not report the same phase rotation then this shutdown will occur.		134

Every row above cites the page of this document it came from, and each one is re-read against that page by an automatic check before publication.

Manufacturer document, published here as reference material for equipment we supply. The original lives at docs.johnsoncontrols.com. The rights holder may ask us to take it down — we will.