easy 3s UPS relay short circuit problem

[Saad_Mahmoud]

the UPS easy 3s 3:1 15KVA unit began exhibiting intermittent and repeated faults while operating under normal conditions. The fault behavior is inconsistent and presents in two distinct patterns:

Fault Pattern 1:

• All front panel LEDs turn off.
• Only the Alarm and Output LEDs remain illuminated in green 
• The unit does not switch to bypass mode.
• Occasionally, the Inverter LED lights up in red, and at the same time, the Alarm LED also illuminates in red, indicating a possible inverter-related fault 

Fault Pattern 2:

• All front panel LEDs turn off.
• The following LEDs illuminate in green:
  • Bypass
  • Output
  • Alarm
• In this case, the unit transitions into bypass mode, supplying power to the load via the bypass line 

In both scenarios, the system continues to cycle between normal operation and fault mode.

 Alarms and Error Messages

During these fault events, the following alarms are observed:

1. Rectifier Inoperable 
2. DC Bus Overvoltage 
3. Relay Short-Circuit 

[KarimEissa · Accepted solution]

Hello,

Regarding the raised faults ,probably  these PCBAs: output power board, input power board, rectifier power board and DC fuse detection board encountered a hardware malfunction and it needs to be  visually checked onsite after logs examining by our SRs or authorized service partners  ,so please contact your local CCC team and they will assist you for onsite visit to diagnose and replace the faulty boards accordingly 

Regards,

Karim