The unit will trip to protect itself. Identify and remove the short circuit on the load side before attempting a restart. Maintenance Bypass Procedure
Ensure the Load is still receiving power from the Bypass source. Press the button to clear alarms. Navigate the control panel to the "Inverter ON" command.
[Normal Mode: Inverter Powered] │ ▼ [Transfer to Static Bypass via Screen] │ ▼ [Close Maintenance Bypass Breaker (Q3)] │ ▼ [Open Inverter Output Breaker (Q2)] │ ▼ [Open Rectifier Input Breaker (Q1)] Step 1: Transfer to Static Bypass Navigate the LCD display panel to the command menu.
| Symptom / Alarm | Most Likely Cause | Your Immediate Action | | :--- | :--- | :--- | | UPS completely dead, no lights | Loss of input power or input fuse | Check upstream breakers, reset them. Check and replace input fuse. | | EMERGENCY STOP displayed | EPO button has been pressed (local or remote) | Investigate cause. If accidental, reset EPO and restart UPS. | | INV. OVERTEMP. / Fan noise issues | Cooling failure or poor ventilation | Check ambient temperature, clear air vents, check fans for operation. | | OVERLOAD PRESENT | Too much equipment is plugged in | turn off non-critical loads to reduce total draw. | | INV: OVER/UNDERVOLTAGE | Serious internal inverter failure | The unit needs professional repair. Call for service. | | Batteries run down too quickly | Batteries have reached end of life | Schedule a certified battery replacement service. | liebert hipulse d ups manual fix
If the issue persists, the phase sequence may be incorrect (Phase reversal). C. Clearing "Battery Low Trip" or "Battery Over Voltage"
Restart the rectifier via the operator control panel once input power stabilizes. Inverter Desaturation / Inverter Fault
If the battery voltage is too low, the system may need to remain in bypass for 2–4 hours to allow for "Normal charge" to occur. The unit will trip to protect itself
If you cannot find the manual and the UPS is stuck in fault mode, but your load is critical, you must perform a to remove the UPS from the circuit. This is the only "manual fix" that does not strictly require the book, but you must follow its logic.
Slide out the intake air filters located at the bottom of the cabinet doors. Wash or replace them.
UPS shuts down with "Over temp" even in a cool room. Fans spin but alarms persist. Press the button to clear alarms
Isolate the DC energy source completely.
Capacitors inside the Liebert Hipulse D hold high-voltage DC power long after the AC input is disconnected. Wait at least 10 minutes after complete shutdown before touching internal components.