J-III 3-Phase VRF - Compressor Stops After Severe Voltage Drop
This article summarises Service Bulletin VRF-0158, issued on 2 March 2018, covering a software issue that can cause the compressor to stop and not automatically recover if the outdoor-unit supply voltage drops significantly while the compressor is running.
| Reference | VRF-0158 |
| Issued | 2 March 2018 |
| Product | J-III 3-phase outdoor unit |
| Subject | Software bug - compressor may stop at low voltage |
Key symptom: If the outdoor-unit supply voltage drops by approximately 18% or more below rated voltage while the compressor is operating, the compressor may stop and fail to restart automatically. The indoor units can continue operating as fan-only and no error code may be displayed.
Occurrence Condition
- The symptom occurs when the supply voltage drops by 18% or more relative to the rated voltage while the compressor is running.
- The compressor stops when a voltage drop occurs between two phases in the three-phase supply.
- The compressor may then remain stopped and not recover automatically.
- The symptom does not occur when the voltage drops while the compressor is already OFF / in standby.
- The guaranteed product operating range stated in the bulletin is ±10% of rated voltage.
Important context: An 18% voltage drop is outside the guaranteed operating range. The bulletin estimates that occurrence in the market is extremely low.
System Condition When the Fault Occurs
- The indoor unit continues to run, but only as fan operation.
- The customer may complain that the system is running but is not cooling or heating.
- No error indication may be shown on either the indoor or outdoor unit.
- The bulletin states that smoke, ignition and electrical leakage do not occur as part of this symptom.
Recovery Method
Recovery: Reset the outdoor-unit circuit breaker. The bulletin states that the system recovers after the outdoor unit is power-reset.
Applicable Models and Serial Numbers
Europe
| Model | Applicable Serial Number |
|---|---|
| AJY040LELAH | R000447 onward |
| AJY045LELAH | R000383 onward |
| AJY054LELAH | R001007 onward |
| AJH040LELAH | R000078 onward |
| AJH045LELAH | R000069 onward |
| AJH054LELAH | R000124 onward |
Middle East
| Model | Applicable Serial Number |
|---|---|
| AJH040LETAHN | T000026 onward |
| AJH045LETAHN | T000042 onward |
| AJH054LETAHN | T000020 onward |
Countermeasure Inverter PCB
| Service part number | 9709681244 |
| PCB rating / name | K15CB-1500HUE-TR1-SV |
| Countermeasure supply | March 2018 onward |
| Identification | Version A29 or later |
How to identify the revised PCB: Check the PCB label. The bulletin identifies the countermeasure version as A29 or later.
Service Guidance
- If the system is running fan-only with no cooling/heating and no error code, check whether a severe supply-voltage event has occurred.
- Measure and verify the three-phase supply and investigate any phase-to-phase voltage drop or unstable mains condition.
- If the compressor remains stopped after the voltage has recovered, reset the outdoor-unit breaker.
- If the symptom repeats, confirm the unit model, serial number and inverter PCB version.
- If required, replace the inverter PCB with the countermeasure service part 9709681244 and confirm the PCB version is A29 or later.
Service Bulletin Images
The original Freshdesk-hosted bulletin images are retained below for reference.
