Support

Support

FAQs Library
Q
How to Troubleshoot UPS Fault Code 65?
2026-09-04
A

Troubleshooting for UPS Fault Code 65, Applicable Model: HT(R)X 01-20KVA S L
Q: The UPS displays fault code 65 and fails to start normally. According to the user manual, this fault indicates low battery voltage. How should we troubleshoot this issue?

A: When this series of UPS triggers fault code 65, the control logic will prevent normal startup. This fault is mainly caused by three factors: faulty UPS charger, damaged batteries, or abnormal battery voltage detection circuit.
Please follow the steps below to locate the root cause:
1.Check the actual battery voltage and confirm whether it matches the value displayed on the UPS screen, so as to determine whether the fault originates from the detection circuit on the power board.
1)If consistent:
Disconnect the two battery BUS cables connected to the UPS power board and restart the UPS. Next, measure the DC voltage at the battery BUS cable terminals on the power board to verify whether the measured voltage is roughly equal to the reading shown on the UPS screen and check if the UPS can start normally.
NOTES:
Make sure to discharge the capacitors at these terminals before disconnecting or reconnecting the battery BUS cables.
2)If inconsistent: The battery voltage detection circuit on the power board may be damaged, which requires replacement of the power board.

Q
What are the precautions for using BAU (Back-feed Absorbing Unit ) to connect UPS?
2026-09-04
A

1. Due to the current limitation of the UPS cabinet back board, only one interface of one BAU can be connected to the module back board of one UPS cabinet.
2. It is recommended to connect the working input terminal of BAU to the output N terminal of UPS, rather than the main input N terminal of UPS, to prevent the disconnection of the N wire in the UPS circuit (such as turning off the output switch of UPS, the N wire of UPS will be disconnected), which may cause interruption of the N wire on BAU and result in abnormal voltage sampling of BAU, causing damage to BAU during operation.
3. The standard voltage version of BAU is currently applicable to power modules of PM25X, PM30X, PM40X, and PM50X.

Q
Can 12028-00008 be used as a hardware replacement for the 12028-00021 IGBT in the SPC5K5TR40?
2026-09-04
A

The SPC5K5TR40 IGBT is broken. In theory, 12028-00021 should be used, but feedback indicates there is no stock. Can I use 12028-00008 as a replacement in hardware?
A: The sizes of the electrical component heat sinks for these two part numbers are the same, so they can be substituted as long as the dimensions match.

Q
How to fix a VFD communication fault?
2026-09-04
A

1. Check if the VFD is still lighting up. If not, you’ll need to replace the VFD board.
2. Check the RS485 cable between the main control board and the VFD board to see if it’s loose.

Q
What should I do if the control module indicator on an iSmart/iWit cabinet is flashing?
2026-08-28
A

 1: Check if the control module's power supply is normal. The indicator flashing means two possible reasons: 1. The power supply is not reaching 220V, 2. There is a short circuit in the devices connected to the control module. Test each of the devices one by one to troubleshoot.

Q
How to deal with an outdoor fan fault when using an EC fan for the air conditioner under automatic control logic?
2026-08-28
A

1. Check if the outdoor fan can work.  
2. Use manual control logic to adjust the outdoor fan speed, from low to high, and see at what speed the outdoor fan fault alarm appears. Then check if there is any rubbing between the fan and the guide vane ring.

Q
How to deal with a low pressure alarm on the air conditioner?
2026-08-28
A

A: 1. Use a pressure gauge to check the pressure inside the copper pipe to see if the alarm is caused by a lack of refrigerant.
2. Check if the indoor fan switch is turned off, which can cause the cooling to accumulate on the evaporator and make the evaporator temperature too low.

Q
When a iSmart/iWit cabinet has a control module communication alarm, how to fix it?
2026-08-28
A

1. Check the IP settings of the control module. The main cabinet must be set to 1, and the following sub-cabinets must be set in the order of 2, 3, 4.
2. Check if the wiring between the cabinets is correct.

Q
How can PLC communication with the GD350A be maintained when the GD350A is powered off?
2026-08-28
A

When using the GD350A (equipped with a communication expansion card) to communicate with a PLC via EIP/EtherCAT/Modbus TCP, what can be done if the inverter loses power but the customer requires communication between the PLC and the GD350A to remain uninterrupted?

 A: The key to maintaining communication is ensuring that the control board remains powered. All GD350A models have at least two expansion card slots; you can optionally install a 24V power supply expansion card to continuously power the control board, thereby maintaining communication.

12345 Show:
You can also view:
Service IntroductionValue added ServiceTraining DownloadFAQsProduct QueryReport a Vulnerability

Product Inquiry
Name:*
Company:
Country:*
E-mail Address:*
Phone:
Content:*

Our site uses cookies to provide you with a better onsite experience. By continuing to browse the site you are agreeing to our use of cookies in accordance with our Cookie Policy.