Engineering guide
XPC M90-80 and M90-140 alarm messages
The XPC M90-80 and M90-140 are discontinued; XPC lists the M90U-80 and M90U-140 as their replacements. Many frames are still in service, and XPC's pages for both link the M90U-80 & 140 user manual, whose alarm list and troubleshooting table this guide follows. On these frames, every warning in the history log carries the Module ID of the power module that raised it, which is the first thing to note.
Key facts
- M90-80: discontinued, replaced by the M90U-80
- M90-140: discontinued, replaced by the M90U-140
- History events: up to 500 events, each with alarm code, alarm time and Module ID
- Warning! Over Load Fail: Line mode will transfer to Bypass mode
Start with the module number
The history log keeps up to 500 events. For a warning it records the alarm code, the time and the Module ID; for a fault, the alarm details, the time and the Module ID. On a frame with several power modules, the Module ID tells the technician which slot to look at, so write it down with the message.
If your frame shipped with an older edition of the manual, check its own alarm list as well; the messages below are from the edition XPC links today.
Load and redundancy messages
| Message on the display | What the manual says | What to do |
|---|---|---|
| Warning! Over Load | In Line mode, the loads demand more power than the UPS can supply. | Reduce some load and check output capacity. |
| Warning! Over Load Fail | Overload; Line mode will transfer to Bypass mode. | Reduce some load; the load is on bypass meanwhile. |
| Fault! Over Load Fault | Heavy overload causes a UPS fault. | Reduce some load. |
| Warning! Redundancy Set Fail | Redundancy setting failed, as stated. | Have the redundancy setting checked against the installed modules. |
If the load has grown since commissioning, compare it with the capacity of the installed modules before clearing any redundancy message.
Battery messages
| Message on the display | What the manual says | What to do |
|---|---|---|
| Warning! Battery Open | Battery not connected. | The manual's first check is the battery breaker; have someone trained look. |
| Warning! Battery voltage High | Battery voltage too high. | Call service to check the nominal battery voltage setting. |
| Warning! Battery Age Alert | Battery life expiration. | Check the age of the strings; plan replacement. |
| Fault! Battery Fault | Battery reverse. | Call service personnel. |
Module, parallel and bypass switch messages
| Message on the display | What the manual says | What to do |
|---|---|---|
| Warning! Module Un-Lock | A module is not locked, as stated. | Have the module latch checked by whoever last worked on the frame. |
| Warning! ID Conflict | Two power modules share the same ID. | Call service personnel. |
| Warning! Parallel Rack Cable Loosen | Parallel rack cable loose, as stated. | Call service personnel. |
| Fault! Parallel Cable Loosen Fault | Parallel cable loose, as stated. | Call service personnel. |
| Warning! Maintenance Bypass | The unit entered maintenance bypass. | Check whether maintenance is under way. |
Supply, EPO and heat messages
| Message on the display | What the manual says | What to do |
|---|---|---|
| Warning! EPO Active | EPO active; check the EPO connector. | Find what triggered the EPO. |
| Fault! Over Temperature | Space for air vents and a working fan are needed. | Check the room temperature and clearance; or call service. |
| Fault! Bypass Temperature Fault | Bypass temperature fault, as stated. | Check the room temperature; or call service. |
| Warning! Fan Lock | A fan is locked. | Check from outside that the air inlet is clear; or call service. |
| Warning! N Loss | Neutral loss. | Have the neutral connection checked; call service. |
| Warning! Line Phase Error | Mains phase sequence error. | Have the phase sequence checked; call service. |
Faults that need a technician
| Message on the display | What the manual says | What to do |
|---|---|---|
| Fault! Bus Soft Start Time Out | Rectifiers could not start: low DC bus voltage. | Turn off and restart once; if it fails again, call service. |
| Fault! Line SCR Fail | Line SCR short circuit fault. | Call service personnel. |
| Fault! CAN Fault | CAN communication fault. | Call service personnel. |
| Warning! EEPROM Fail | EEPROM operation error. | Call service personnel. |
| Warning! Charge Fail | Charger failure. | Call service personnel. |
Keep the cabinet closed and the load where the UPS placed it. Our field service for XPC modular frames covers installed M90-80 and M90-140 units as well as their M90U successors, and suspect power modules can go through module repair and testing.
Related pages
Common questions
Is the XPC M90-80 still supported?
XPC lists the M90-80 as discontinued and replaced by the M90U-80. Installed frames are still serviced in the field.
Which manual covers M90-80 and M90-140 alarms?
XPC's product pages for both link the M90U-80 & 140 User & Installation Manual, which this guide follows.
Why does the event log show a Module ID?
Each warning and fault is recorded with the Module ID, so the technician knows which power module raised it.
What does Warning! Over Load Fail mean?
The loads demand more power than the UPS can supply, and Line mode transfers to Bypass mode. Reduce some load.
What should I do on Warning! ID Conflict?
Two power modules share the same ID. Call service personnel.
Sources, checked October 4, 2026:
- XPC M90-80 Modular Online Three Phase UPS product page (xpcc.com)
- XPC M90-140 Modular Online Three Phase UPS product page (xpcc.com)
- Xtreme Power Conversion M90U-80 & 140 User & Installation Manual (Rev 2/19/24), linked from the M90-80 and M90-140 pages, 4.2.8.2 History Events, p. 60
- Xtreme Power Conversion M90U-80 & 140 User & Installation Manual (Rev 2/19/24), linked from the M90-80 and M90-140 pages, chapter 6 Troubleshooting, p. 68-71
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