Transformer hot with no load Back-UPS RS 1500

Anonymous user · ‎2021-06-28

Hi,

I have an older RS 1500 unit, with batteries recently replaced. Unit operates normally, and batteries are 100% charged.

All self-tests are OK.

However, without any load, top of the unit (transformer) is quite warm .

Is this normal, or this indicates some problem with UPS?

BillP · ‎2021-06-28

Hi Dan,

This is normal of the older RS 1500. The internal transformer is used for charging the batteries as well as for boosting or trimming incoming power. Unlike Schneider Electrics' newer RS 1500, the transformer is always active in the older APC units which would explain the heat. The newer units electrically isolate the transformer when it is not required for critical operating conditions, therefore consuming less power during Online operations.

Secret Squirrel

See Answer In Context

BillP · ‎2021-06-28

Hi Dan,

This is normal of the older RS 1500. The internal transformer is used for charging the batteries as well as for boosting or trimming incoming power. Unlike Schneider Electrics' newer RS 1500, the transformer is always active in the older APC units which would explain the heat. The newer units electrically isolate the transformer when it is not required for critical operating conditions, therefore consuming less power during Online operations.

Secret Squirrel