OT:Eaton UPS buzzing all the time

We had a power cut this morning, and when power was restored, my Eaton UPS (which powers a server) just sat there buzzing. Manual says this means it's overloaded ... thing is I disconnected the load. Has anyone any ideas ?

Typical, the one time you need it .....

Reply to
Jethro
Loading thread data ...

Sounds like its under load, so maybe its bust. I never liked them to start with. Only ever had one and it never worked properly. Brian

Reply to
Brian Gaff

Do you mean it failed to cover the outage and just buzzed with no appreciable backup power. Or that it started buzzing when the power came back?

My APC unit buzzes a bit when it's supplying backup power but it's always done that. What condition are the batteries in, they don't last for ever even if they aren't used in anger very often. I get at best 3 years or so from a set in my APC unit. Batteries in the UPS box so they cook.

Has your power come back at the correct voltage? We had a short, 5 min, power cut late saturday night a week or so back. Voltage on return was down at 220 and varied by 15v upwards. Just in spec. Next night there was another short outage and the volts went from 225 to

250. Then stayed at that sort of level again with the 15v variation and going out of spec (>253v) at times. Our normal supply is 235 to 245. The fun you can have witha UPS and logging the voltage... The slightly worrying thing is that the customer facing part of the REC didn't know about the fault, neither did the engineer who came out when I complained, nor did his local office, only the operational control center knew that the 33kV feed to the local main substation had gone pop so we were on the 11kV backup as I had guessed.
Reply to
Dave Liquorice

As others have said, sounds dead in some way. Always worth a regular test of UPSs - we only discovered the battery was dead in one when the power went. Problem is that the power test in some of them works by...

  1. Block mains and switch to battery
  2. Check how well battery is working
  3. Report status.

Of course all this is bollocks if the battery is dead because the thing just dies at step 1 ! I would hope that the newer models now just try to gently draw some power from the battery but it's worth finding out.

Also, if possible, have it report status via e-mail or similar so you get a regular "I'm OK" or an "I'm knackered" if the battery is failing - APC models can do this but don't know about other makes.

Paul DS.

Reply to
Paul D Smith

Which model is it? I had a brand new 3S a few days ago that was making a continuous tone from its piezo speaker, and would not stop until I disconnected and reconnected the battery. I am still not sure if it charged up OK because the sparks on site had to turn off the power, so I couldn't do the job I was there to do.

I'm still not sure if it was faulty or just too flat.

Reply to
Graham.

Can the buzzer also mean there's not enough energy stored to provide power for some minimum duration (such as 3 minutes)? This is how some other UPS's work.

This can happen if you don't do calibration runs a few times a year, so the UPS only finds out the battery capacity is very low when it actually has to use the batteries for real (which it also treats as a calibration run). If the capacity remaining is less than can supply your load for the minimum duration, then the bleep is to indicate the UPS won't last long enough because either the batteries are too dead (too little capacity remaining), or the load is too high.

The capacity of SLA batteries in the cheaper UPS's seems to decay linearly with time, typically reaching zero after about

4 years (3 years in some cases).
Reply to
Andrew Gabriel

They can but in my experience the regular check by the thing going onto battery for a few seconds every week shortens the battery life noticeably. With regular tests 3 years battery life if you are lucky, without tests 5 years...

Reply to
Dave Liquorice

Definitely. My APC Smart-UPS 1000 batteries have never been allowed to perform the self-test and they're now knocking on for 9 years old. I run an occasional manual test on them and the most recent showed them to still have 90% capacity - which is ok, as all it does is perform a graceful shutdown in two minutes, the battery life being plenty for that.

Reply to
grimly4

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.