Brand: AEG
Category: Power Supply
Document Type: Manual
Language: EN
Manual for PROTECT C.
Uploaded: April 20, 2026, 7:57 p.m.
Manual Publish Date: 2009-12-03
Warranty Information
The warranty does not apply to damage caused by non-compliance with these instructions.
Basic Operation
The PROTECT C. UPS is designed to provide continuous power to essential loads like PCs, workstations, and servers. It features a mains filter for surge protection, a rectifier with PFC logic, a separate battery charger, a sealed maintenance-free battery system, an IGBT inverter for sinusoidal AC output, and an automatic bypass for redundancy.
The unit connects between the mains and the devices to be protected. In normal operation, it draws power from the mains, conditions it, and supplies it to the load while simultaneously charging the battery. In case of a mains failure, the inverter seamlessly switches to battery power without interruption.
The automatic bypass acts as a backup, directly connecting the mains to the load if the inverter malfunctions. The UPS also has communication interfaces for monitoring and shutdown software.
Troubleshooting and error codes
| Problem | Cause | Solution |
|---|---|---|
| UPS does not start. No indication, no audible signal even though system is connected to mains power supply. | Mains and battery voltage not in the tolerance range, possible battery deep discharge. | Check building wiring socket outlet and input cable. |
| LED "Line" flashes and audible signal sounding every 3 minutes. | Phase and neutral conductor at input of UPS system are reversed. | Rotate mains power socket by 180° or connect UPS system. |
| LED "Line" flashes and LED "Battery" lights up. | Input power and/or frequency are out of tolerance. | Check input power source (Voltage, frequency) and inform house electrician if necessary. |
| LED "Line" and LED "Bypass" light up even though the power supply is available. No supply of connected loads. | Inverter not switched on. | Press On-Switch "ON" for about 2 seconds. |
| LED "Inverter" and LED "Battery" lights up, and audible signal sounding every 4 seconds. | Mains power supply has failed. Automatic switch to battery mode. | Try to replace mains supply (possibly triggered fuse in sub distribution). When audible alarm sounding every second, battery is almost unloaded. At this point it is time to proceed with an system shutdown of all you IT equipment. |
| LED "fault" lights, audible signal once a second. | Overload of the UPS system. | Reduce utilizations of UPS by removing loads of UPS output. |
| Emergency supply period shorter than nominal value | Batteries not fully charged / batteries old resp. defect | Charge the batteries for at least for the charging time acc. Chapter 3.4, page 16 and then check capacity. If the problem still persists, consult your dealer. |
| LED "fault" lights, LED "Battery" flashes, audible signal once a second | Charger or Batteries damaged | Notify dealer! |
| LED "fault" lights up, permanent audible signal | UPS fault | Notify dealer! |