| Document type | Installation Operation and Maintenance Guide |
|---|---|
| Document number | 201.28-NM1.1 |
| Equipment | YVAA Style A |
| Brand | YORK |
| Revised | 2025-12-22 |
| File size | 7.8 MB |
Fault codes in this document
Unit warning
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT WARNING: !! LOW BATTERY !! CHECK SETPOINTS/PROGRAM/OPTIONS/TIME | Low Real Time Clock (RTC) battery voltage detected at micropanel power-up. | On micropanel power-up the RTC battery is checked to see if it is still operational; if the battery voltage is determined to be low, this warning message is displayed indefinitely. | All programmed setpoints, program values, time, schedule, and history buffers have been lost and are reset to their default values, which may not be the correct operating values. After a bad battery is detected, the unit is prevented from running until the manual override key is pressed; after pressing the manual override key, the anti-recycle timers are set to the programmed default anti-recycle time to allow the operator sufficient time to check setpoints, program values, and other relevant values. Replace the battery as soon as possible — the programmed values will all be lost and the unit will be prevented from running on the next power interruption. | 139 |
| UNIT WARNING: INVALID NUMBER OF COMPRESSORS SELECTED | Invalid Number of Compressors Select jumper configuration. | Occurs after the VSD has been initialized, if no jumpers are installed or if more than 1 jumper is installed. | To clear this warning, both the control panel and VSD control voltage must be turned OFF and the jumpers properly installed in the VSD wiring harness. | 139 |
| UNIT WARNING: INVALID SERIAL NUMBER ENTER UNIT SERIAL NUMBER | Chiller serial number invalid or lost. | The appearance of this message may mean the chiller has lost important factory programmed information. | Immediately contact Johnson Controls Product Technical Support. The serial number can be entered using the SERVICE key. This status message can be bypassed to view additional messages under the STATUS key by pressing the STATUS key repeatedly to scroll through as many as three STATUS messages that could possibly be displayed at any time. | 139 |
Unit safeties
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT YYYYYYYY HIGH AMBIENT TEMP | Ambient air temperature above the maximum allowable value. | Ambient temperature rises above 55°C (131°F). | Chiller shuts down with a controlled ramped shutdown. Restart will automatically occur, if demand allows, when temperature falls 1.1°C (2°F) below the cutout (53.9°C [129°F]). This fault cannot cause a lockout. The fault display message is present only during the time when the ambient temperature is causing a fault condition. The unit is also inhibited from starting any time the temperature is above 53.9°C (129°F). | 140 |
| UNIT YYYYYYYY LOW AMBIENT TEMP | Ambient air temperature below the programmed cutout. | Ambient temperature falls below the programmable Low Ambient Temp Cutout. This fault only occurs if the Low Ambient Cutout is ENABLED under the OPTIONS key. | Chiller shuts down with a controlled ramped shutdown. Restart can occur, if demand allows, when temperature rises 1.1°C (2°F) above the cutout. This fault cannot cause a lockout. The fault display message is present only during the time when the ambient temperature is causing a fault condition. The unit is also inhibited from starting any time the temperature is below the cutout plus 1.1°C (2°F). | 140 |
| UNIT YYYYYYYY LOW LEAVING CHILLED LIQUID TEMP | Leaving chilled liquid temperature below the freeze-protection cutout. | The leaving chilled liquid temperature (water or brine) drops below the programmable cutout point. Helps protect the chiller from an evaporator freeze-up; this situation could occur under low flow conditions or if the Micro Panel setpoint values are improperly programmed. | Chiller faults and shuts down with a controlled ramped shutdown. Restart can occur, if demand allows, when chilled liquid temperature rises 2.2°C (4°F) above the cutout. This fault cannot cause a lockout. The unit is inhibited from starting any time the chilled liquid temperature is below the cutout plus 2.2°C (4°F). | 140 |
| UNIT YYYYYYYY VSD COMMUNICATIONS FAILURE | Loss of communications between the Chiller Control Board and the VSD Logic Board. | On power-up, the Chiller Control Board fails to initialize communications with the VSD Logic Board (no reply from the VSD Logic Board within 8 seconds), or during normal operation the Chiller Control Board receives no valid response to messages for 8 seconds. | Prevents the unit from trying to run; while operating, the unit shuts down all compressors with a controlled ramped shutdown. The Chiller Control Board continues to send messages to the VSD while faulted. The unit is inhibited from starting until communications is established. The fault automatically resets when the Chiller Control Board receives a valid response from the VSD for a data request. | 140 |
System safeties, faults
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| SYS X YYYYYYYY HIGH DISCHARGE PRESSURE | Software high discharge pressure cutout. | Discharge pressure rises above 22.4 barg (325 psig) for 0.5 seconds. | System faults and shuts down with a controlled ramped shutdown. The system is allowed to restart when the discharge pressure falls to 20.3 barg (295 psig). The system is also inhibited from starting if the pressure is above 20.3 barg (295 psig). YYYYYYYY = FAULT (system restarts when the 120 second anti-recycle timer times out) or LOCKOUT (does not restart until the operator clears the fault using the keypad). | 141 |
| SYS X YYYYYYYY HPCO FAULT | Mechanical (hardware) high pressure cutout trip. | The mechanical high pressure cutout contacts open, protecting the system from dangerously high discharge pressure. The cutout opens at 23.2 barg ± 0.55 barg (337 psig ± 8 psig) and closes at 17.4 barg ± 0.69 barg (252 psig ± 10 psig). The HPCO is wired in series with the VSD Run Signal and is only checked by the Chiller Control Board when the system is running. The fault occurs immediately and does not wait 3 seconds. | System faults and shuts down immediately. YYYYYYYY = FAULT (system restarts when the 120 second anti-recycle timer times out) or LOCKOUT (will not restart until the operator clears the fault using the keypad). | 141 |
| SYS X YYYYYYYY LOW SUCTION PRESSURE | Suction pressure below the programmable cutout. | If the system attempts to run with a low refrigerant charge, the programmable LOW SUCTION PRESSURE CUTOUT protects the chiller from an evaporator freeze-up. The cutout is ignored at the system start to allow the initial programmable SUCTION PRESSURE STARTUP BYPASS TIME; immediately after the bypass time expires, the cutout is linearly ramped from 10% to 100% of the programmed Suction Pressure Cutout. | The system shuts down if at any time during the ramp the suction pressure falls below the ramped Suction Pressure Cutout, or if at any time after the ramp the suction pressure falls below the programmable Suction Pressure Cutout. This causes a lockout on the 3rd fault in 90 minutes. | 142 |
| SYS X YYYYYYYY LOW SUCT PRES SMART FREEZE | Suction pressure held below the override threshold longer than permitted (R-134a and R-513A refrigeration systems). | Set when the Suction Pressure is lower than the programmable Suction Pressure Override Threshold (Suction Pressure Cutout in psig + 1.7 psig) for longer than the programmable Smart Freeze Timer. The safety fault is released when the Suction Pressure >= Suction Pressure Override Threshold. | This fault causes a lockout on the 3rd fault in 90 minutes. | 142 |
| SYS X YYYYYYYY LOW MOTOR CURRENT | Absence of motor current detected. | The microprocessor detects the absence of motor current (less than 10% FLA), usually indicating that a compressor is not running. This safety is ignored for the first 10 seconds of operation. | Shuts the system down with a controlled ramped shutdown. YYYYYYYY = FAULT (system restarts when the 120 second anti-recycle timer times out) or LOCKOUT (will not restart until the operator clears the fault using the keypad). | 142 |
| SYS X YYYYYYYY HIGH DIFF OIL PRESSURE | Excessive discharge-to-oil differential pressure (pressure drop across the oil filter). | The Discharge to Oil Differential Pressure rises above the cutout of 4.48 barg (65 psid). Protects the compressor from low oil flow and insufficient lubrication, possibly from a dirty oil filter. This safety is ignored for the first 90 seconds of run time. | System faults and shuts down with a controlled ramped shutdown. YYYYYYYY = FAULT (system restarts when the 120 second anti-recycle timer times out) or LOCKOUT (will not restart until the operator clears the fault using the keypad). | 142 |
| SYS X YYYYYYYY LOW DIFF OIL PRESSURE | Oil-to-suction differential pressure below the cutout (protection against low oil flow and insufficient lubrication). | The differential between oil and suction pressure falls below the cutout. The safety ensures the compressor is pumping sufficiently to push oil through the oil cooling circuit and the internal compressor lubrication system. The safety is ignored for the first 60 seconds of run time; after that the cutout is linearly ramped from 0 barg to 2.09 barg (0 psid to 30 psid) in 5 to 10 minutes based on ambient temperature (see Table 17). A 30 second safety bypass below 50 Hz is employed during rampdown (needed when another compressor is being brought on and the running compressor is ramped down to 5 Hz). | System faults and shuts down with a controlled ramped shutdown. YYYYYYYY = FAULT (system restarts when the 120 second anti-recycle timer times out) or LOCKOUT (will not restart until the operator clears the fault using the keypad). | 143 |
| SYS X YYYYYYYY HIGH DISCHARGE TEMP | Discharge temperature above the cutout (motor and compressor overheat protection). | Discharge Temperature rises above 121°C (250°F). | System faults and shuts down with a controlled ramped shutdown. The system is also inhibited from starting if the discharge temperature is above 93°C (200°F). YYYYYYYY = FAULT (system restarts when the 120 second anti-recycle timer times out) or LOCKOUT (will not restart until the operator clears the fault using the keypad). | 143 |
| Low discharge superheat cutout fault | Protection against liquid floodback through the economizer line due to a high flashtank level, and against excessive oil in circulation due to excess oil charge in the system. | Discharge superheat falls below 2.8°C (5.0°F) for 5 minutes. The safety is ignored for the first 10 minutes of operation if the system economizer feed valve is closed (0%), and for 5 minutes of operation if the economizer feed valve is open greater than 0%. Excessive oil in circulation brings back liquid refrigerant entrained in the oil; the liquid drops out once it enters the compressor. | System shuts down. YYYYYYYY = FAULT (system restarts when the 120 second anti-recycle timer times out) or LOCKOUT (will not restart until the operator clears the fault using the keypad). | 143 |
| SYS X YYYYYYYY SENSOR FAILURE: ZZZZZZZZZZZZ | A critical sensor is failed or reading out of range. ZZZZZZZZZZZZ indicates the failed sensor: SUCT PRESS, OIL PRESS, DSCH PRESS, or MOTOR TEMP X * (* a specific motor temperature sensor can be ignored under the Unit Setup Mode). | A critical sensor (transducer, level sensor, or motor winding temp sensor) is not functioning properly and reading out of range. The safety is checked at startup and will also fault and shut down a system while in operation if a safety threshold is exceeded or a sensor reads out of range (high or low). Start inhibit sensor thresholds (Table 20): Suction Transducer 0.3–4.7 VDC; Oil Transducer 0.3–4.7 VDC; Discharge Transducer 0.3–4.7 VDC; Motor Temp. Sensor 0°C (0°F) to 116°C (240°F). | At startup, prevents the system from running if one of the sensors has failed. During operation, the system faults and shuts down. YYYYYYYY = FAULT (system restarts when the fault clears) or LOCKOUT after 3 faults (will not restart until the operator clears the fault using the keypad). | 145 |
| SYS X YYYYYYYY HIGH MOTOR TEMP | Compressor motor temperature too high. | Any compressor motor temperature sensor rises above 121°C (250°F). The system is inhibited from starting if its motor temperature sensors indicate temperatures above 116°C (240°F). If any single temperature sensor is being ignored under the Unit Set-up Mode, that sensor is not utilized when evaluating motor temperature. | System faults and shuts down. YYYYYYYY = FAULT (system restarts when the fault clears) or LOCKOUT (will not restart until the operator clears the fault using the keypad). | 145 |
| SYS X YYYYYYYY CONTROL VOLTAGE | 115 V AC control voltage missing from one system. | The 115 V AC Control voltage to one of the systems is missing; this could be due to a system fuse that has been removed or is blown. The affected system faults and shuts down immediately when the 115 V AC supply is lost. The safety will not shut down a system if the UNIT switch is OFF (which electrically removes the 115 V AC to all systems); it is only used to indicate a situation where a single system is missing the 115 V AC. | This safety will not cause a lockout; the system fault resets when power is returned. | 145 |
| EDUCTOR CLOG FAULT | Loss of oil return to the compressor through the eductor. | The safety monitors the temperature of the line between the eductor and the suction line once a second. At start, a clog timer is set at 600 seconds; the timer resets to 600 seconds whenever the eductor line temperature is less than the saturated suction temperature plus 5.5°C (10°F). If the eductor line temperature is greater than the saturated suction temperature plus 5.5°C (10°F) for 600 seconds, the clog timer counts to 0. | The system shuts down and locks out. Whenever this fault occurs, the eductor filter should be changed. | 146 |
General status messages
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| UNIT STATUS FLOW SWITCH SHUTDOWN | Chilled liquid flow switch open — flow switch is not allowing the chiller to run. | The flow switch is not allowing the chiller to run. There is a 1 second delay on this safety to ensure the flow switch did not momentarily open. | Chiller is kept shut down while the flow switch is open. | 148 |
| UNIT STATUS VSD COOLING SHUTDOWN | Chiller shut down while the VSD internal ambient temperature is brought down to an acceptable level. | The chiller is shutdown, but running all the condenser fans, VSD glycol pump, and VSD fan in an effort to bring the internal VSD ambient temperature down to an acceptable level before allowing the chiller to start. | Chiller remains shut down (with condenser fans, VSD glycol pump and VSD fan running) until the internal VSD ambient temperature is at an acceptable level, before the chiller is allowed to start. | 148 |
Flash card update error
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| 0 | Okay | 130 | ||
| 10 | Flash card not found. | 130 | ||
| 11 | SOFTWARE.ELF file not found | 130 | ||
| 14 | SOFTWARE.ELF file larger than expected. | 130 | ||
| 15 | RAM to IPU Flash transfer of DATABASE.ELF failed. | 130 | ||
| 16 | RAM to IPU Flash transfer of SOFTWARE.ELF failed. | 130 | ||
| 17 | Could not allocate sufficient memory to read or write file. | 130 | ||
| 99 | Internal software error. | 130 |
Software update errors
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| MORE THAN ONE FILE FOUND | more than on *.bin file on selected device | 132 | ||
| FILE NOT FOUND | *.bin file not on selected device | 132 | ||
| FILE NOT ABLE TO BE LOADED | *.bin file not able to be loaded to flash | 132 | ||
| SELECTED DEVICE NOT FOUND | update attempted without SD or USB | 132 |
Flash errors
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| FILE_BUFFER_APP_HEADER_READ | Error code 90 | 132 | ||
| CANNOT_CALCULATE_BUFFER_DATA_CRC | Error code 91 | 132 | ||
| BAD_FILE_BUFFER_DATA_CRC | Error code 92 | 132 | ||
| SFLASH_DEVICE_WRITE | Error code 93 | 132 | ||
| BAD_SFLASH_CRC | Error code 94 | 132 | ||
| APP_CODE_TOO_BIG | Error code 95 | 132 | ||
| SPI_FLASH_APP_NOT_PRESENT | Error code 96 | 132 | ||
| SPI_FLASH_READ_ERROR | Error code 97 | 132 | ||
| CANNOT_READ_DEVICE_CONFIGURATION | Error code 98 | 132 |
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. | 198 | |
| Line fuse blows. | SCR Diode Module is defective. IBGT Module is defective. VSD Logic Board is defective. SCR Trigger Board is defective. | Check SCR/Diode Module. Check IBGT Module. Replace VSD Logic Board. Replace SCR Trigger Board. | 198 | |
| 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. | 198 | |
| 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. | 198 | |
| 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. | 198 | |
| System fault: Control voltage | System Fuse is blown. | Check respective system Fuse 20FU or 21FU. | 198 | |
| 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. | 199 | |
| System fault: High discharge temperature | Discharge Temperature Sensor is defective. Condenser 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. | 199 | |
| 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. | Check subcooling. Check subcooling. Drain/Feed Valves NOT controlling. Isolate cause. Program panel to ignore a single sensor. Valve is leaking through. | 199 | |
| System fault: Low suction pressure | Low charge. Transducer reads incorrectly. Suction Temp. Sensor reads incorrectly. Low flow. Condenser Drain (Flash Tank Feed) Valve NOT operating. Condenser or Drain (Flash Tank Feed) 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. | 199 | |
| 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. | 199 | |
| VSD fault: High baseplate temperature | Coolant level low. Glycol pump is defective. VSD Board is defective. IBGT Module is defective. | Add coolant. Replace Glycol Pump. Replace VSD Logic Board. Check defective IGBT Module. | 200 | |
| VSD fault: Low DC Bus voltage | SCR/Diode Module is defective. SCR Trigger Board is defective. | Check SCR/Diode Module. Check SCR Trigger Board. | 200 |
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