APC DLA1500 UPS site wiring indicator?

[SArepairman]

Does anyone know if the DLA1500 UPS systems will display a wiring fault if there is no battery connected to them?

I have a unit (with a completely dead battery) that displays a wiring fault light on the back when I plug it in.

I took the unit apart, checked the cables for continuity and did a visual inspection, I don't see any problems.

Does this light come on if there is no battery or does the unit have some other fault? I checked the outlet to see if it is wired correctly (low resistance between neutral and ground + correct polarity).

It seems to be a common fault on ebay but I don't know if this unit is junk or if I can get a new battery for it.

[rexxar]

I guess they could be using the site wiring fault light as a dead battery light, but I don't see why they would. I say make sure there isn't a dead short across the battery connections, and hook it up to a 12V source and see what happens.

[Monkeh]

I guess they could be using the site wiring fault light as a dead battery light, but I don't see why they would. I say make sure there isn't a dead short across the battery connections, and hook it up to a 12V source and see what happens.

It's a 1500VA UPS, it's not going to be 12V.

[metalphreak]

Most of these UPS should still power on with no battery connected. They are designed so you can hot swap the battery packs without powering down the equipment attached to them (otherwise it's pretty worthless as an uninterruptable power souce  )

My APC 1000VA has 24V packs. My 1920W Dell UPS has 72V packs. There is no standard voltage, but generally the higher capacity units will have more batteries in series.

[rexxar]

Most of these UPS should still power on with no battery connected. They are designed so you can hot swap the battery packs without powering down the equipment attached to them (otherwise it's pretty worthless as an uninterruptable power souce  )

The idea is to test the thing before he goes out and buys expensive batteries, which is why I suggested powering it from an external supply. The last failed unit I got from fleabay worked fine, until I put in the battery and BANG  An SLA has a lot of current to put through a shorted switching FET. A current-limited supply should cut down on the pyrotechnics.

Thinking about it again, though.. I wonder if the site wiring fault light isn't discreetly driven? I have a couple of borked APC units here, and while I haven't traced out the whole circuit, it looks like there's a couple transistors detecting the mains wiring. If it's a common fault for this unit, maybe that circuit is the problem, and the actual UPS is fine?