Back-UPS RS 500 Continuous Clicking Noise

[khun.roger_apc]

I have an old (6-10 years?) Back-UPS RS 500 which developed a fault a couple of years ago so I simply bought a new UPS.

But now I would like to try to get it to work again.

I can't remember exactly what happened to cause the fault, but the situation now is that when it is connected to the mains power supply, it emits a rapid clicking noise. The noise sounds like a relay cutting in and out, It makes this noise very rapidly - about 5 times per second, so I don't leave it running like that for fear of damaging the relay.

I am sure the battery is not good. I measured the voltage directly across the battery terminals - with no load being drawn - and it was 3.9 v. But, don't forget, the battery has been lying around for 2 years so it may have lost any charge it had, although it hadn't been connected to anything during that time.

So I'm hoping someone will say: "Oh, yes. When the battery has failed the 'overcharge suppression protection relay' cuts in and out and you get that noise - just buy a new battery".

What I'm hoping the reply will not be is: "Ah, yes. The old series RS-500 tended to develop a fault in the flux capacitor which cannot be repaired. Sorry".

So, over to the knowledgeable guys at APC...

[Anonymous user]

On 2/19/2016 1:37 PM, Khun said:

So, over to the knowledgeable guys at APC...

Well, I'm just an end user who isn't in any way affiliated with either of APC or Schneider Electric, but I have used a lot of APC products over the years and even repaired a few along the way. That said, I'm not sure how much help I can be, as it looks the Back-UPS RS 500 (BR500CI-RS?) is for those parts of the world using 230 volt, 50 Hz electrical systems.

The battery you've got right now is almost certainly a lost cause, and some models that aren't part of the Smart-UPS family do need a good battery to start up properly (or at all). I've never seen one fire its relays like crazy, but I have had one that whistled like a teakettle and dropped the attached load when the battery pooped out. A new battery brought it right back to life. So I'd beg, borrow, maybe even STEAL  a slightly better battery and see what the unit does. It wouldn't have to be a great battery, just one that's got enough zip left to let the unit start up if that is what it needs in order to do so. If it comes around, a new battery is probably all you need.

In models similar to this (the Back-UPS CS series seems most similar to my eyes), faulty capacitors are known to cause strange behavior. If you know how to solder and can work on an electronic device utilizing high current and some line connected circuitry safely, it's a cheap and very easy fix. (Only to be done at your entire risk, however. APC doesn't consider their products as repairable by the end user.)

There is also the possibility of welded relays. These will usually trigger some nasty noises from the unit, and a light show or beeping fit from the control panel to indicate the fault. This model seems like it should have at least three relays -- one for primary power on/off control to its outlets, another to connect the inverter to the load, and a third for the AVR function.

With a faulty battery, the unit could also be attempting to cycle on to battery in response to what it sees as some kind of a power problem, only to fall flat on its face and start over again repeatedly. I don't know what charging methodology this unit uses, but there are some, particularly later models, that use a pulsed methodology and this might be audible if the regulation is being pulled down by a bad battery.

I'd start out with a better battery as a test, though.

[khun.roger_apc · Accepted solution]

On 2/20/2016 5:19 AM, William said:

Well, I'm just an end user who isn't in any way affiliated with either of APC or Schneider Electric, but ...

...I'd start out with a better battery as a test, though.

Yes, I'm in 230V, 50Hz land in Asia. I also have many APC UPSs:

Back-UPS Pro 1500 *2
Back-UPS Pro 900
Back-UPS 800
Back-UPS RS 500 - this faulty one.

I only just found the 800 in my pile of computer bits  , so I may as well use that one for the job I was going to use the RS 500. But I would still like to get the 500 sorted out.

I did try the 500 with another battery - an old motor bike battery with a similar spec., but different physical size - and it gave the same result. So then I measured its unloaded output voltage and it, too, was about 3.9v. So I reckon both batteries are effectively dead.

Your video has given me an idea...   I'll do the same and post it to Youtube so you can near what's happening.

I'll post a link later.

Later: Here's the link Back-UPS RS 500 Fault

After I made the video, I noticed the muck leaking out of the battery on the left side. Shows it is kaput, I guess. But does that explain the noise?

[Anonymous user]

Oh yeah, that's definitely relay noise. Wow! I've never seen one do that before.

I can't say for certain that a new battery will solve it, only that it is probably worth enough of a try to consider borrowing one from another unit, if you've got any that still have working batteries.

The serial number places your Back-UPS RS 500 at right around six years old (50th week of 2009).

[khun.roger_apc]

I haven't been able to try a new battery yet - been sick with a heavy cold, but may do tomorrow.

I do appreciate your help, William, but I'm surprised that no actual APC technical support person has given any information. 

This forum is on a APC.com server so I had assumed some APC tech support people would also read the posts and comment.

[BillP]

Hi,

William gave you some very good troubleshooting steps. It is possible a depleted battery could cause the issue. Our recommendation is to test with a known good battery. If the unit still exhibits the issue with a known good battery the UPS should be replace. Schneider Electrics policy for Back-UPS is they do not have any user replicable component other than the battery. We offer a trade-UPS program where you trade in the old UPS for a new UPS at a discount. That way the old UPS is returned and recycled / scrapped properly. 

[khun.roger_apc]

On 2/22/2016 10:11 AM, Bill said:

Hi,

William gave you some very good troubleshooting steps. It is possible a depleted battery could cause the issue. Our recommendation is to test with a known good battery. If the unit still exhibits the issue with a known good battery the UPS should be replace. Schneider Electrics policy for Back-UPS is they do not have any user replicable component other than the battery. We offer a trade-UPS program where you trade in the old UPS for a new UPS at a discount. That way the old UPS is returned and recycled / scrapped properly. 

Hi Bill,

I agree - everything William posted made perfect sense to me, I was just hoping that a tech guy from APC would concur.

Unfortunately I don't have any other working batteries - apart from the ones in my other 4 APC UPSs, which I don't want to dismantle, and in my pick-up - so I'll buy a new one tomorrow and see if that helps.

Regarding the trade-UPS program, is that available from Thailand and, if so, what would the procedure be?

Thanks for your help.

Khun Roger

[BillP]

Hi,

Sorry for the delay in my reply. Unfortunately Schneider Electric does not offer the trade-UPS program in Thailand. If you are interested in a replacement I suggest you contact local sales support http://www.apc.com/site/support/index.cfm/contact-information/ they will be able to assist you with your options. 

[khun.roger_apc]

Hi Bill,

That's OK - not much works here in Thailand 😉   

Actually, I've just ordered a "Back-UPS 625VA 325W with Universal Sockets (BX625CI-MS)" from a local (Thailand) Internet store.

If I ever get a new battery for the RS-500 and get it working again, I'll post about it here.

Thanks for your help.

Roger

(PS. I've "straightened out" my name so it displays as "Roger" rather than "Khun" 🙂 )

[khun.roger_apc]

Hi William,

I finally managed to find and fit the correct sized (and shaped) battery in the RS 500 and I am happy to say that it is now working OK. So  the rapid clicking has now stopped and it gives the usual beep when turned on, and beeps when the power supply to it is off.

Hope this story helps others who may wonder what that noise is: My Noisy UPS

[Anonymous user]

I'm glad to hear you got it going again, and that it was as simple as installing a new battery.