| Document type | Installation Guide |
|---|---|
| Document number | 201.21-NM3 |
| Equipment | YCAV Variable Speed Drive Screw Chiller |
| Brand | YORK |
| Revised | 2026-07-09 |
| File size | 23.0 MB |
Fault codes in this document
VSD safeties (faults)
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT YYYYYYYY PRECHARGE - LOW DC BUS VOLTAGE SYS X YYYYYYYY PRECHARGE - LOW DC BUS VOLT | Pre-charge Low DC Bus Voltage (Software) Fault. DC bus voltage did not reach at least 50 VDC within 4 seconds and 500 VDC within 19 seconds after the pre-charge signal was asserted. | Auto-restart safety; unit/system shuts down and restarts when the fault clears. Locks out on the 3rd fault in 90 minutes. Unit fault on 2- and 3-compressor chillers; System 1/3 or 2/4 fault on 4-compressor chillers. A LOCKOUT will not restart until the operator clears the fault using the keypad. | 246 | |
| UNIT YYYYYYYY PRECHARGE - DC BUS VOLTAGE IMBALANCE SYS X YYYYYYYY PRECHARGE-BUS VOLT IMBAL | Pre-charge DC Bus Voltage Imbalance (Software) Fault. During the pre-charge interval the 1/2 DC bus voltage magnitude must remain within +/-100 VDC of the total DC bus voltage divided by two; unit/system shuts down if it does not. | Locks out on the 1st fault. Unit fault on 2- and 3-compressor chillers; System 1/3 or 2/4 fault on 4-compressor chillers (two presses of the STATUS key required to show the fault on both systems). Operator must clear the lockout using the keypad. | 246 | |
| UNIT YYYYYYYY HIGH DC BUS VOLTAGE SYS X YYYYYYYY HIGH DC BUS VOLTAGE | High DC Bus Voltage (Hardware) Fault. Trip level determined by hardware on the VSD Logic Board at 766 +/- 30 VDC; unit/system faults and shuts down immediately if the DC bus exceeds this level. | Auto-restart safety; locks out on the 3rd fault in 90 minutes. Unit fault on 2- and 3-compressor chillers; System 1/3 or 2/4 fault on 4-compressor chillers. | 246 | |
| UNIT YYYYYYYY LOW DC BUS VOLTAGE SYS X YYYYYYYY LOW DC BUS VOLTAGE | Low DC Bus Voltage (Software) Fault. Trip level set at 500 VDC; unit/system faults and shuts down immediately if the DC bus drops below this level. | Auto-restart safety; locks out on the 3rd fault in 90 minutes. Unit fault on 2- and 3-compressor chillers; System 1/3 or 2/4 fault on 4-compressor chillers. | 247 | |
| UNIT YYYYYYYY DC BUS VOLTAGE IMBALANCE SYS X YYYYYYYY DC BUS VOLTAGE IMBALANCE | DC Bus Voltage Imbalance (Software) Fault. The 1/2 DC bus voltage magnitude must remain within +/-100 VDC of the total DC bus voltage divided by two; unit/system faults and shuts down immediately if exceeded. | Locks out on the 1st fault. Unit fault on 2- and 3-compressor chillers; System 1/3 or 2/4 fault on 4-compressor chillers. | 247 | |
| SYS X YYYYYYYY HIGH MOTOR CURRENT | High Motor Current (Hardware) Fault. Three phases of instantaneous output current per compressor compared to a predetermined hardware limit. Nominal peak current trip level 575.5 Amps (554 A min., 597 A max.); 380V AC 60 Hz and 400V AC 50 Hz nominal peak trip level 649.5 Amps (626 A min., 674 A max.). Immediate shutdown if the peak current limit is exceeded. | Auto-restart safety; locks out the system on the 3rd fault in 90 minutes. Individual system/compressor fault for all units. | 247 | |
| SYS X YYYYYYYY MOTOR CURRENT OVERLOAD | Motor Current Overload (Software) Fault. Highest of the 3 phases of motor current per compressor compared to the compressor's 105% FLA ADJUST (overload) potentiometer setting on the VSD Logic Board; compressor trips if the setting is exceeded continuously for 20 seconds. Controlled ramped shutdown. | Locks out the system on the 1st fault. Individual system/compressor fault for all systems. | 248 | |
| UNIT YYYYYYYY MOTOR CURRENT OVERLOAD | Motor Current Overload (Hardware) Fault. Highest of the 3 phases of motor current per compressor compared to the compressor's overload ADJUST potentiometer setting; if exceeded continuously for 30 seconds, all compressors fault and shut down immediately. | Unit fault; locks out all systems on the first fault. Will not restart until the operator clears the fault using the keypad. | 248 | |
| SYS X YYYYYYYY GATE DRIVER | IGBT Gate Driver (Hardware) Fault. Gate driver board monitors the saturation voltage drop across each of the six IGBTs while gated on; if the saturation voltage exceeds the prescribed limit a short circuit is determined and all IGBTs in the module are turned off immediately. The same fault is generated if the gate driver board power supply voltage falls below the permissible limit. | Auto-restart safety; locks out on the 3rd fault in 90 minutes. System fault for all units. | 248 | |
| SYS X YYYYYYYY HIGH VSD BASEPLATE TEMP | High Baseplate Temperature (Software) Fault. Limits: 2-compressor chillers — System 1 and System 2 sensors each compared to 218°F; 3-compressor chillers — compressors 1 and 3 OR'd, highest compared to 232°F, compressor #2 individually to 232°F; 4-compressor chillers — compressors 1/3 OR'd and 2/4 OR'd, each compared to 218°F. Controlled ramped shutdown when the limit is exceeded. | Auto-restart safety; locks out on the 3rd fault in 90 minutes. System fault for all units. After a fault the fan(s) and water pump remain energized until the inverter power module base plate temperature(s) fall below 165°F; the system is allowed to restart when the base plate temperatures drop below this value. | 249 | |
| UNIT YYYYYYYY HIGH VSD INTERNAL AMBIENT TEMP | High VSD Internal Ambient Temperature (Software) Fault. VSD internal ambient temperature rises above the cutout of 158°F; controlled ramped shutdown. | This safety will not cause a lockout. Unit fault for all units. Unit allowed to restart when the internal ambient temperature drops 10°F below the cutout. | 249 | |
| UNIT YYYYYYYY SINGLE PHASE INPUT VOLTAGE SYS X YYYYYYYY SINGLE PHASE INPUT VOLTS | Single Phase Input (Hardware) Fault. The VSD's SCR Trigger Control board checks the three-phase mains for the presence of all three line voltages; immediate shutdown if any line voltage is not present. | Does not cause a lockout. Unit fault on 2- and 3-compressor chillers; System 1/3 or 2/4 fault on 4-compressor chillers. Restarts when the single phase condition clears. | 249 | |
| UNIT YYYYYYYY VSD LOGIC BOARD POWER SUPPLY | Power Supply (Hardware) Fault. Various DC power supplies which power the VSD Logic Board are monitored via hardware; immediate shutdown if any supply falls outside its allowable limits. | Auto-restart safety; restarts after the fault clears and locks out on the 3rd fault in 90 minutes. Unit fault for all units. | 250 | |
| SYS X YYYYYYYY VSD RUN RELAY | Run Relay (Software) Fault. Upon receipt of a run command (hardware and software) a 5-second timer commences; the system faults if the missing run signal is not asserted within the 5-second window. If either run signal is disabled while the VSD is running, the remaining run signal must be disabled within 5 seconds after the VSD is shut down or the system faults. Controlled ramped shutdown if running. | Auto-restart safety; autostarts after the 120-second anti-recycle timer times out and locks out on the 3rd fault in 90 minutes. System fault on 2-compressor units; combined 1/3 or 2/4 system fault on 3- and 4-compressor units. | 250 | |
| UNIT YYYYYYYY VSD LOGIC BOARD FAILURE | VSD Logic Board Failure (Software) Fault. The PWM generator does not acknowledge the voltage and frequency commands within 1.5 seconds of issue. Active only during precharge and while a compressor is running; if it occurs while the chiller is running, all systems immediately shut down. | Auto-restart safety; auto restarts after the 120-second anti-recycle timer times out and locks out on the 3rd fault in 90 minutes. Unit fault for all units. | 250 | |
| UNIT YYYYYYYY VSD CT PLUG FAULT | VSD CT Plug (Hardware) Fault. Jumpers installed in each CT plug on the VSD Logic Board feed back signals indicating the plugs are installed; if either plug is not installed a low value is read on the digital input and the unit shuts down immediately or will not run if off. | Auto-restart safety; restarts after the 120-second anti-recycle timer times out and locks out on the 3rd fault in 90 minutes. Unit fault for all units. | 250 |
Unit warnings
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT WARNING: !! LOW BATTERY !! CHECK SETPOINTS/PROGRAM/OPTIONS/TIME | Low Battery Warning. Occurs only at unit power-up; the RTC battery voltage is determined to be low. All programmed setpoints, program values, time, schedule, and history buffers have been lost and reset to default values, which may not be the desired operating values. | Low RTC battery (located on the Chiller Logic Board). | Unit is prevented from running until the MANUAL OVERRIDE key is pressed; anti-recycle timers are then set to the programmed default to allow the operator time to check setpoints, program values, etc. Replace the battery as soon as possible. | 252 |
| UNIT WARNING: INVALID NUMBER OF COMPRESSORS SELECTED | Invalid Number of Compressors Warning. Occurs after the VSD has been initialized. | No "Number of Compressors Select" jumpers installed, or more than 1 jumper installed in the VSD wiring harness (J1 plug). | To clear the warning, both the control panel and VSD control voltage must be turned off and the jumpers properly installed in the VSD wiring harness. Start-up of the unit is inhibited while the warning is present. | 255 |
| UNIT WARNING: INVALID SERIAL NUMBER ENTER UNIT SERIAL NUMBER | Invalid Serial Number Warning. May mean the chiller has lost important factory programmed information. An Optimized IPLV chiller will only run in Standard IPLV control mode while this warning is present. | Serial number not programmed into the panel / factory programmed information lost. | Immediately contact YORK Product Technical Support. Enter the serial number using the Service Key with the factory-provided password (date/time must be set first; password is time sensitive). Message can be bypassed to view additional STATUS messages by pressing the STATUS key repeatedly. | 255 |
| UNIT WARNING: OPTIMIZED EFFICIENCY DISABLED - CONTACT YORK REPRESENTATIVE | Optimized Efficiency Disabled warning. Means an optimized (High IPLV) chiller is programmed for standard control. | High IPLV (Optimized) mode not enabled. | Immediately contact YORK Product Technical Support or YORK ES Commercial for a password. Enable Optimized IPLV via the Service Key; the message disappears once enabled. Message can be bypassed to view additional STATUS messages by pressing the STATUS key repeatedly. | 255 |
Flash card update error XXXXX
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| Error code 10 | Flash card not found. | 254 | ||
| Error code 11 | SOFTWARE.BIN file not found | 254 | ||
| Error code 14 | SOFTWARE.BIN file larger than expected. | 254 | ||
| Error code 15 | RAM to IPU Flash transfer of DATABASE.BIN failed. | 254 | ||
| Error code 16 | RAM to IPU Flash transfer of SOFTWARE.BIN failed. | 254 | ||
| Error code 17 | Could not allocate sufficient memory to read or write file. | 254 | ||
| Error code 99 | Internal software error. | 254 |
Unit safeties
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT YYYYYYYY LOW AMBIENT TEMP | Low Ambient Temp Fault. Ambient temperature falls below the programmable Low Ambient Temp Cutout; controlled ramped shutdown. Only occurs if the Low Ambient Cutout is "ENABLED" under the OPTIONS key. | Cannot cause a lockout. Restart, if demand allows, when temperature rises 2°F above the cutout. Unit is also inhibited from starting any time the temperature is below the cutout + 2°F. | 256 | |
| UNIT YYYYYYYY LOW LEAVING CHILLED LIQUID TEMP | Low Leaving Chilled Liquid Temp Fault. Leaving chilled liquid temperature drops below the programmable cutout point; helps protect the chiller from evaporator freeze-up. Controlled ramped shutdown. | Low flow conditions or improperly programmed micro panel setpoint values. | Cannot cause a lockout. Restart, if demand allows, when chilled liquid temperature rises 4°F above the cutout. Unit is inhibited from starting any time the chilled liquid temperature is below the cutout + 4°F. | 257 |
| UNIT YYYYYYYY VSD COMMUNICATIONS FAILURE | VSD Communications Failure Fault. Chiller Control Board never initializes communications with the VSD Logic Board, or receives no valid response to messages for 8 seconds during operation; all compressors shut down with a controlled ramped shutdown. | Unit is inhibited from starting until communications is established. The Chiller Control Board continues sending messages to the VSD while faulted. Fault automatically resets when the Chiller Control Board receives a valid response from the VSD. | 257 |
System safeties (faults)
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| SYS X YYYYYYYY HIGH DISCHARGE PRESSURE | High Discharge Pressure Cutout (Software) Fault. Discharge pressure rises above 274 PSIG for 0.5 seconds; controlled ramped shutdown. | System allowed to restart when discharge pressure falls to 259 PSIG; inhibited from starting if the pressure is above 259 PSIG. Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 258 | |
| SYS X YYYYYYYY HPCO FAULT | High Discharge Pressure Cutout (HPCO) (Hardware) Fault. Mechanical high pressure cutout contacts open; immediate fault and shutdown (does not wait 3 seconds). Wired in series with the VSD Run Signal and checked only when the system is running. Cutout opens at 297 +/-8 PSIG and closes at 230 +/-10 PSIG. | Restarts when the 120-second anti-recycle timer times out; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 259 | |
| SYS X YYYYYYYY LOW SUCTION PRESSURE | Low Suction Pressure Cutout (Software) Fault. Programmable secondary back-up for the flow switch; protects against operation with low refrigerant charge and evaporator freeze-up. Ignored for the first 30 seconds of run time; over the next 3 minutes the cutout ramps linearly from 10% of the programmed cutout up to the programmed point. After 3 minutes 30 seconds, a transient override sets a 30-second linearly ramped cutout starting at 10% of the programmed cutout. Typically set at 24 PSIG for chilled water applications. Controlled ramped shutdown. | Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 259 | |
| SYS X YYYYYYYY LOW MOTOR CURRENT | Low Motor Current Cutout Fault. Absence of motor current (<10%FLA) detected, usually indicating that a compressor is not running; controlled ramped shutdown. Ignored for the first 10 seconds of operation. | Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 259 | |
| SYS X YYYYYYYY HIGH DIFF OIL PRESSURE | High Differential Oil Pressure Cutout Fault. Discharge-to-oil differential pressure (the pressure drop across the oil filter) rises above the cutout of 65 PSID; protects the compressor from low oil flow and insufficient lubrication. Ignored for the first 90 seconds of run time. Controlled ramped shutdown. | Possibly a dirty oil filter. | Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 260 |
| SYS X YYYYYYYY LOW DIFF OIL PRESSURE | Low Differential Oil Pressure Cutout Fault. Differential between oil and suction pressure falls below the cutout; assures the compressor is pumping sufficiently to push oil through the oil cooling circuit and internal lubrication system. Ignored for the first 60 seconds of run time; cutout then ramps linearly from 0 PSID to 30 PSID over 5–10 minutes based on ambient temperature (>50°F: 5 min; >45°F: 6 min; >40°F: 7 min; >35°F: 8 min; >30°F: 9 min; ≤30°F: 10 min). A 30-second safety bypass below 50 Hertz applies during rampdown. Controlled ramped shutdown. | Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 260 | |
| SYS X YYYYYYYY HIGH DSCHARGE TEMP | High Discharge Temperature Cutout Fault. Discharge temperature rises above 250°F; protects the motor and compressor from overheating. Controlled ramped shutdown. | System inhibited from starting if discharge temperature is above 200°F. Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 260 | |
| SYS X YYYYYYYY HIGH OIL TEMP | High Oil Temperature Cutout Fault. Oil temperature rises above 225°F; protects the compressor from insufficient lubrication. Controlled ramped shutdown. | System inhibited from starting if oil temperature is above 175°F. Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 261 | |
| SYS X YYYYYYYY LOW SUCTION SUPERHEAT | Low Suction Superheat Cutout Fault. Helps protect the compressor from liquid floodback due to low suction superheat. Ignored for the first 30 seconds of compressor operation. Faults when any of the following occur: after the first 30 seconds, suction superheat <2.0°F with discharge superheat <15°F and run time <5 minutes (cutout set to 0°F and linearly ramped to 2.0°F over the next 60 seconds); suction superheat <2°F and discharge superheat <15°F for 10 seconds with run time ≥5 minutes; suction superheat <0.5°F with discharge superheat >15°F for 60 seconds and run time ≥5 minutes; suction superheat <5°F for 10 minutes. Controlled ramped shutdown. | Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 261 | |
| SYS X YYYYYYYY LOW DISCHARGE SUPERHEAT | Low Discharge Superheat Cutout Fault. Helps protect the compressor primarily from liquid floodback through the economizer line due to a high flash tank level; also provides suction-line floodback protection in conjunction with the low superheat safety. Ignored for the first 5 minutes of compressor operation. After the first 5 minutes of run time, faults if discharge superheat falls below 10.0°F for 5 minutes. Controlled ramped shutdown. | Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 261 | |
| SYS X YYYYYYYY SENSOR FAILURE: ZZZZZZZZZZZZ | Sensor Failure Cutout Fault. Critical sensor (transducer, level sensor, or motor winding temp sensor) not functioning properly and reading out of range. Checked at start-up and prevents the system from running; also faults and shuts down a running system. ZZZZZZZZZZZZ indicates the failed sensor: SUCT PRESS, OIL PRESS, DSCH PRESS, LEVEL SENSOR, or MOTOR TEMP X. Start inhibit thresholds: suction/oil/discharge transducers 0.3–4.7 VDC; level sensor 3.0–21.0 mA; motor temp sensor 0–240°F. | Critical sensor failed or reading out of range. | Restarts when the fault clears; locks out after 3 faults (operator clears via the keypad). The Unit Setup Mode allows a specific motor temperature sensor to be ignored if it fails. | 262 |
| SYS X YYYYYYYY HIGH MOTOR TEMP | High Motor Temperature Cutout Fault. Any compressor motor temperature sensor rises above 250°F; prevents a compressor from running when its motor temperature is too high. | System inhibited from starting if its motor temperature sensors indicate temperatures above 240°F. A sensor being ignored under the Unit Set-up Mode is not utilized when evaluating motor temperature. Auto-restarts when the fault clears; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 262 | |
| SYS X YYYYYYYY HIGH FLASH TANK LEVEL | High Flash Tank Level Cutout Fault. Liquid level in the flash tank is too high. Ignored for the first 15 seconds of system operation; fault occurs if the tank level is greater than 85% for 10 seconds. | Auto-restarts after the 120-second anti-recycle timer; locks out after 3 faults on the same system within 90 minutes (lockout cleared by cycling the system switch OFF and ON). | 263 | |
| SYS X YYYYYYYY CONTROL VOLTAGE | System Control Voltage Cutout Fault. Alerts the operator that the 115V AC control voltage to one of the systems is missing; the affected system faults and shuts down immediately when the 115V AC supply is lost. Does not shut down a system if the Unit Switch is OFF (which removes 115V AC to all systems). | A system fuse has been removed or is blown. | Will not cause a lockout; the system fault resets when power is returned. | 263 |
ISN fault and inhibit codes
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| 1 | Low Ambient Temp. (Unit / Panel) | 329 | ||
| 2 | High Ambient Temp. (Unit / Panel) | 329 | ||
| 3 | Low Chilled Liquid Temp. (Unit / Panel) | 329 | ||
| 5 | Low RTC Battery Voltage (Unit / Panel) | 329 | ||
| 6 | Invalid Number of Compressors Selected (Unit / Panel) | 329 | ||
| 7 | VSD Communications Failure (Unit / Panel) | 329 | ||
| 8 | Pre-charge Low DC Bus Voltage (Unit / VSD) | 329 | ||
| 9 | Pre-charge DC Bus Voltage Imbalance (Unit / VSD) | 329 | ||
| 10 | High DC Bus Voltage (Unit / VSD) | 329 | ||
| 11 | Low DC Bus Voltage (Unit / VSD) | 329 | ||
| 12 | DC Bus Voltage Imbalance (Unit / VSD) | 329 | ||
| 13 | High VSD Ambient Temp. (Unit / VSD) | 329 | ||
| 14 | Single Phase Input (Unit / VSD) | 329 | ||
| 15 | VSD Power Supply Fault (Unit / VSD) | 329 | ||
| 16 | VSD Logic Board Fault (Unit / VSD) | 329 | ||
| 17 | Motor Current Overload (Hardware) (Unit / VSD) | 329 | ||
| 18 | CT Plug Fault (Unit / VSD) | 329 | ||
| 27 | High Discharge Pressure (Software) (System / Panel) | 329 | ||
| 28 | High Differential Oil Pressure (System / Panel) | 329 | ||
| 29 | Low Differential Oil Pressure (System / Panel) | 329 | ||
| 30 | Low Suction Pressure (System / Panel) | 329 | ||
| 31 | High Discharge Temp. (System / Panel) | 329 | ||
| 32 | High Oil Temp. (System / Panel) | 329 | ||
| 33 | Low Suction Superheat (System / Panel) | 329 | ||
| 34 | Sensor Failure (System / Panel) | 329 | ||
| 35 | Low Motor Current (System / Panel) | 329 | ||
| 36 | High Motor Temperature (System / Panel) | 329 | ||
| 37 | Pre-charge Low DC Bus Voltage (System / VSD) | 330 | ||
| 38 | Pre-charge DC Bus Voltage Imbalance (System / VSD) | 330 | ||
| 39 | High Dc Bus Voltage (System / VSD) | 330 | ||
| 40 | Low DC Bus Voltage (System / VSD) | 330 | ||
| 41 | DC Bus Voltage Imbalance (System / VSD) | 330 | ||
| 42 | High Motor Current (System / VSD) | 330 | ||
| 43 | Motor Current Overload (Software) (System / VSD) | 330 | ||
| 44 | IGBT Gate Driver Fault (System / VSD) | 330 | ||
| 45 | High Baseplate Temp. (System / VSD) | 330 | ||
| 46 | Single Phase Input (System / VSD) | 330 | ||
| 47 | VSD Run Signal Fault (System / VSD) | 330 | ||
| 48 | High Discharge Press (Hardware-HPCO) (System / Panel) | 330 | ||
| 49 | High Flash Tank Level (System / Panel) | 330 | ||
| 50 | Control Voltage Fault (System / Panel) | 330 | ||
| 51 | Low Discharge Superheat (System / Panel) | 330 |
Troubleshooting guide
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| No Display on Control Panel. Unit will NOT Run. | Supply to the Panel is missing. High Voltage to the Chiller is missing. Line Fuse is blown. Chiller Control board is defective. Display Board defective. | Check 1FU, 2FU, 4FU, 5FU 17FU, or 19FU. Check 2T or 10T Transformer. Check Fuses. Replace Chiller Control board Replace Display Board | 337 | |
| Line Fuse Blows. | SCR Diode Module is defective. IGBT Module is defective. VSD Logic Board is defective. SCR Trigger Board is defective | Check SCR/Diode Module. Check IGBT Module. Replace VSD Logic Board. Replace SCR Trigger Board. | 337 | |
| Chiller Fault: LOW AMBIENT TEMPERATURE | Ambient temperature is lower than the programmed operating limit. Ambient Sensor is defective. | Check the programmed cutout and determine if it is programmed correctly Check the panel against the thermometer reading of ambient temperature | 337 | |
| Chiller Fault: HIGH AMBIENT TEMPERATURE | Ambient Temperature is above the maximum operating limit. Ambient Sensor is defective. | Check outside air temperature. Check the Panel Display against Thermometer reading of Ambient Temperature at the sensor. | 337 | |
| Chiller Fault: LOW LEAVING CHILLED LIQUID | Leaving chilled liquid temperature drops faster than the unit can unload. Water loop is too small. Flow is below minimum for chiller. Chilled Water Sensor is defective. | Check for restricted flow. Check for rapid flow changes. Check Sensor against Temp. Gauge in water line. Check Sensor for intermittent operation. Check Wiring for shorts or opens. | 337 | |
| System Fault: CONTROL VOLTAGE | System Fuse is blown. | Check respective system Fuse 20FU or 21FU. | 337 | |
| System Fault: HIGH OIL TEMPERATURE | Oil Temperature Sensor is defective. Condensor Fans NOT operating or running backwards. Coils dirty. | Check Sensor with infrared to determine if reading is reasonable. Check Fans. Check and clean Coils. | 337 | |
| System Fault: HIGH DISCHARGE PRESSURE | Coils dirty. Coils are damaged. Fans NOT operating. System is overcharged. | Check and clean coils. Comb out fins. Check fan fuses. Check fan rotation. Check fan motor/blade. Remove charge and check subcooling. | 338 | |
| System Fault: HIGH DISCHARGE TEMPERATURE | Discharge Temperature Sensor is defective. Condensor Fans NOT operating or are running backwards. Coils dirty. High Superheat. | Check Sensor. Check Fans. Check and clean Coils. Measure Superheat with gauges and thermocouple. Determine cause. | 338 | |
| System Fault: HIGH MOTOR TEMPERATURE | High Motor temperature input from one of the sensors Refrigerant charge low. Excess charge in system, High discharge pressure. High Superheat. Motor Sensor reading incorrectly. Economizer Solenoid energized at low speeds. Valve is leaking through. | Check subcooling. Check subcooling. Drain/Feed Valves NOT controlling. Isolate cause. Program panel to ignore a single sensor. | 338 | |
| System Fault: LOW SUCTION PRESSURE | Low charge. Transducer reads incorrectly. Suction Temp. Sensor reads incorrectly. Low flow. Feed or Drain Valve NOT operating Feed or Drain Valve defective. | Check subcooling. Check transducer against a gauge. Check sensor against a thermocouple. Check flow. Check Feed and Drain Valve operation. Check superheat. Check Feed and Drain Valve operation. Check superheat. | 338 | |
| System Fault: DISCHARGE PRESSURE LIMITING | Discharge Transducer is defective. Ambient Temp. very high. Fans NOT operating. Remote or local discharge pressure load limiting is programmed. | Check transducer against a gauge. Normal operation. Check fan operation. Normal operation. | 338 | |
| System Fault: MOTOR CURRENT LIMITING | High motor current has activated current limiting Ambient temperature is high, Remote or panel limiting is in effect, Excess charge in system, Condensor coils dirty, Fans NOT operating, | normal response from controller Normal response. adjust charge. Clean condensor. Check fans. | 339 | |
| VSD Fault: High Baseplate Temperature | Coolant level low. Glycol Pump is defective. VSD Board is defective IGBT Module is defective. | Add coolant. Replace Glycol Pump. Replace VSD Logic Board. Check defective IGBT Module. | 339 | |
| VSD Fault: Low DC Bus Voltage | SCR / Diode Module is defective. SCR Trigger Board is defective. | Check SCR / Diode Module. Check SCR Trigger board. | 339 |
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