APC Back-ups ES 700G - white noise

[BillP]

Hi,

I own 4 UPS, Back-ups ES serie : 2 x ES 500G, 2 x ES 700G.

On both ES 700G, whenever they are plugged to the wall socket, there is a white noise. It is a high pitched noise coming from an area close to the battery slot.

This is not occuring on any ES 500G. They all function well, though the noise is annoying.

I tested on different sockets.

I am very surprised of this difference between the 2 models.

Any suggestion on the rootcause or how to get rid of the noise ?

[BillP]

Hi,

I own 4 UPS, Back-ups ES serie : 2 x ES 500G, 2 x ES 700G.

On both ES 700G, whenever they are plugged to the wall socket, there is a white noise. It is a high pitched noise coming from an area close to the battery slot.

This is not occuring on any ES 500G. They all function well, though the noise is annoying.

I tested on different sockets.

I am very surprised of this difference between the 2 models.

Any suggestion on the rootcause or how to get rid of the noise ?

[BillP · Accepted solution]

Hello, here is what went through my mind for ideas:

1. The two wall sockets you tried, are they at the same location and also on the same circuit?
2. Does the UPS still do it when you have nothing plugged into it for power?
3. Does the sound change at all when a load is connected?
4. Did you just purchase the UPS or did this develop over time?
5. Does the noise go away when the UPS goes on to battery power?
6. Are the sensitivity settings the same on both UPS models?