Back UPS cs 650 - Power to "Surge Protect" outlet but no power to the "Battery Backup" power outlets

[Anonymous user]

As in the title I have a Back UPS CS 650 and its been out of service for a while, so I replaced the battery and;

-it fires up fine with a new battery

-Solid Green Power Light

-Self test in Power Chute PASSES without note

-In powerchute indicates battery is full and AC supply is 258V

-Surge Protected outlet has power - 255V (multimeter)

-Battery Backup outlets (all 3) have 0.00 voltage (multimeter)

-Battery cables from unit unplugged from battery - 13.5V

-Battery Cables plugged into battery - 12.5V

Not sure what other info I can provide, but not sure why I can't seem to get power through the battery. Tried a second battery (not brand new but not dead) and got the exact same results, on battery voltage was 12.0 on the older battery.

Am I missing something obvious or is there a fault in this unit somewhere?

Thanks in advance for anyone who has time to comment.

[BillP]

Hi,

If you cold start the UPS (start from battery not AC) is power passed to the outlets? If that is the case it could be a bad relay. If not it is most likely a bad connection. The unit is not considered user repairable but the test should help you understand the possible cause. 

[Anonymous user]

It does fire up fine with no AC and power the battery backup points.

Where would i find the offending relay?

I'll have our electrician electrician check it out.

Thanks for taking the time to reply, its much appreciated.

Josh

[Anonymous user · Accepted solution]

Before I get to anything else, please be aware that these units are dangerous to work on. If you don't have the knowledge to safely repair high power electronic devices, the only safe option is to replace the unit. I'm deadly serious: these units can kill a person if they don't understand what's going on inside. They are considered to be non-repairable by APC.

All of that said, the relay is inside the unit, mounted to the main printed circuit board. It is soldered in place. One would have to diagnose not only the relay's driving circuit (is it outputting enough voltage to close the relay's contacts?) and the relay itself (which could have developed burned contacts or simply failed in some other way). Bad solder joints are not unheard of.

Your electrician might have knowledge sufficient to investigate and repair the problem, although you really want someone skilled in electronics repair. Of course, if you find someone willing to work on the unit, it may cost as much as a new one to have it fixed. Another problem is that of schematics not being readily available for these units.