Nasty squeals from an older Smart-UPS 750...

[nickds1]

I tend to use APC/Schneider Smart-UPS UPS systems at home...

I have an older one, an SMT-750, which makes a fairly horrid noise on battery. Self-test passes fine, but when on battery I don't much like the noise...

Bit loathe to chuck it as they are expensive, but have a listen... bin job or repair?

Note: I have replaced this unit with a brand new SMT750IC which is very happy, but I'd like to see if there are options on this older device before I condemn it to the recyclers...

[Teken]

The inverter circuit is clearly faulty so the choices are to recycle, trade up.

Given you have already purchased a new replacement. Using the APC trade up program may be something you might consider down the road if you need a hot spare.

The vast majority of times it’s the relays inside of the unit that just need to be replaced. 👍

[nickds1]

Ah! I assumed the inverter, or some of the iron, was on the way out. Being fair, it is 20 years old!

I didn't know about the trade in/up program... is there one in the UK?

Thanks

[Teken]

Give this link a try and report back any difficulties: 

https://www.apc.com/shop/tradeups/uk/en/tradeups/overview.jsp

Cheers! 👍