Manual for HE

Manual for HE

Brand: AEG

Category: Other

Document Type: Manual

Language: EN

Uploaded: April 20, 2026, 7:46 p.m.

Warranty Information

The warranty period is 24 months.

The AEG HE UPS systems utilize IGBT technology for high changeover frequency, resulting in low current distortion and stable output voltage. They are on-line, double conversion units, ensuring uninterrupted clean power by continuously supplying the load from the inverter. This configuration provides immunity to mains variations and protects critical loads. The UPS operates in normal, bypass, battery, or manual bypass modes, depending on conditions like mains failure or maintenance requirements. Key components include the rectifier, inverter, battery charger, and static/manual bypass for load management and protection.

Troubleshooting and error codes

Alarm Description Possible causes Solutions
A5 DC VOLTAGE FAULT The measured DC voltage is out of tolerance.
  • The battery has reached the discharge voltage due to a power failure.
  • Measuring circuit failure.
 1) Check the actual value of the measured DC voltage. 2) In case of mains failure, wait for the AC voltage to be restored. 3) Check which alarms are present and carry out the indicated procedures. 4) Restart the device. 5) If the alarm persists, contact our Technical Support Service.
A7 BCB OPEN The battery isolator is open.
  • Battery isolator open.
 1) Check the status of the battery isolator. 2) Check the functionality of the auxiliary contact of the isolator. 3) Check the connection between the auxiliary contact of the isolator and the auxiliary terminals of the UPS (if provided). 4) If the alarm persists, contact our Technical Support Service.
A12 STOP TIMEOUT SC Inverter shutdown due to an extended short-circuit during a power failure, or due to an overcurrent on the inverter bridge input.
  • Short-circuit on the loads during a power failure.
  • Inverter bridge fault.
  • Temporary current peak.
 1) Reset the system. 2) If the alarm persists, contact our Technical Support Service.
A13 INV OUT OF TOL The inverter voltage or frequency is out of tolerance.
  • Inverter shutdown due to an alarm.
  • Inverter failure.
 1) Check which alarms are present and carry out the indicated procedures. 2) If the alarm persists, contact our Technical Support Service.
A14 BYPASS WR SEQ The phase rotation of the bypass line is wrong.
  • Wrong connection of power cables.
 1) Check the phase rotation. 2) If the alarm persists, contact our Technical Support Service.
A15 BYPASS FAULT The voltage or frequency of the bypass line is out of tolerance.
  • Bypass line instability or failure.
  • Wrong phase rotation.
 1) Check the connections to the mains. 2) Check the stability of mains voltage. 3) If the alarm persists, contact our Technical Support Service.
A20 OVERLOAD The current sensor has detected an overload at the output. If the alarm persists, the thermal image protection will be activated (alarm A21).
  • Output overload.
  • Measuring circuit failure.
 1) Check the loads connected to the UPS output. 2) Contact our Technical Support Service.
A21 THERMAL IMAGE The thermal image protection has been activated after an extended inverter overload. The inverter is shut down for 30 minutes and then restarted.
  • Output overload.
  • Measuring circuit failure.
 1) Check the loads connected to the UPS output. 2) Should you need to restore the inverter supply immediately, reset the system. 3) If the alarm persists, contact our Technical Support Service.
A23 EPO PRESSED The system is blocked due to the activation of the emergency power off button.
  • Activation of the (local or remote) emergency power-off button.
 1) Release the emergency power off button and reset the alarm. 2) If the alarm persists, contact our Technical Support Service.
A32 EPO BUS CLOSED The system is blocked due to the activation of the emergency power off button.
  • Activation of the (local or remote) emergency power-off button.
 1) Release the emergency power off button and reset the alarm. 2) If the alarm persists, contact our Technical Support Service.
A50 SSW BLOCKED The static switch is blocked. The load is no longer supplied.
  • Loads failure.
  • Possible UPS fault.
 1) Check the loads for possible failures. 2) Reset the system. 3) If the alarm persists, contact our Technical Support Service.
A63 START SEQ BLOCK During the UPS start-up a failure prevented the proper execution of the sequence.
  • Control devices in wrong position or operated improperly.
  • Possible internal fault.
 1) Make sure the position of the control devices (isolators, selectors) is as specified in the procedures (see "Installation and start-up" section). 2) If the alarm persists, contact our Technical Support Service.
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