APC UPS repair

Mine was SUA1000 but applies to every Smart Ups from APC.

Suddenly turns off with the six main status leds blinking all together.

This case is not covered by the user manual troubleshooting, and is not to be confused with the over temperature signal (all the battery & load leds blinking together).

Thanks to this video the probelem appears to be common and imputable to one or more defective relays.

To be sure of the problem, the test consists in powering the UPS with a VARIAC (Variable Transformer).

Adjusting the variac to provide a high or low input voltage, the UPS goes trim or boost respectively.

If the UPS shuts down with the six leds flashing simultaneously when the voltage is high OR low OR in both cases, the problem is confirmed.

For a SUA1000 the relais are:

• 3 pcs OMRON G2R-1-E (24VDC, SPDT, 250VAC/16A)
• 1 pcs OEN INDIA 68-24-2AE (24VDC, DPST-NO, 250VAC/8A)