Back UPS 1500 XS LCD... Top of unit feels hot. When should the fans be r

[Anonymous user]

Hi,

I noticed that the top of my Back UPS 1500 XS LCD felt quite warm... so I looked at the back and the fans sis not seem to be running. When are they supposed to turn on?

Is this unit supposed to feel warm on top?

Thanks.

[Anonymous user]

When the unit is supplying power from the batteries, it gets much hotter, that's when the fans are supposed to be on.

[BillP]

the fan should come on when the UPS is on battery or the UPS is charging the battery. i believe it may come on when the UPS goes over a certain load percentage (not sure what though) and also if the internal temperature of the UPS goes over a certain threshold (not sure what the threshold is though).

[Anonymous user · Accepted solution]

To my knowledge the unit should NOT have been charging the battery. Computer is not on often... UPS feels hot even when MacPro has not been on. Is the something I should worry about?

Any other Back UPS 1500 XS LCD owners out there care to share?

[Anonymous user]

Inside UPSes there is usually a power transformer which serves for two purposes, one is for voltage regulation and the other is for transforming 12Volts DC from the batteries to +-115Volts AC. While operating from the mains, the power transformer is constantly energized, but is not supplying power to the load then when the voltage boost kicks in (or the voltage trim in other models), the power transformer starts supplying a regulated output. What I'm trying to say here is that the power transformer is always on, only waiting to be requested. So If you could touch the power transformer with your bare hands, you wouldn't be able to keep your them there for too long and that's normal, power transformers do get very hot. What you're feeling on the outside of the unit is just a small percentage of the heat coming out of the transformer.