UPS battery backup making random clicking noises.

[Carfax83]

I've been having this problem recently with my UPS, which is a CyberPower CP1500AVRLCD Intelligent LCD UPS 1500VA 900W.

The problem is that the UPS will rapidly switch between AC and DC and then back again, usually in a second or so. It will do this seemingly randomly every few minutes..

It does this REGARDLESS of whether my PC is turned on or off, and I noticed that when it happens, the lights will dim in the bathroom..

I've had this particular unit since 2009 so it's fairly old, and I had bought spare batteries for it a couple years back. Although I didn't really think it was a battery issue, I changed the batteries anyway just to be sure, but the problem still persisted.

So my question is, what can cause this to happen? As I said, I've had this unit for years and only recently has it started to do this..

Is it simply malfunctioning because it's so old? It supposedly has automatic voltage regulation to protect from fluctuating voltage. Can such a thing fail over time?

 

[LTC8K6]

Sounds like your mains power is briefly dropping low.

 

[Carfax83]

Sounds like your mains power is briefly dropping low.

Thanks for the reply. I used Cyberpower's monitoring software to check the voltage output in realtime, and it never detected any under voltage when it spontaneously went into battery mode.. The lowest the voltage dropped to was 119v, which shouldn't even trigger the UPS to go into battery mode.

Which is why I'm wondering if the relays themselves could be malfunctioning, or the AVR..

A really weird problem to be sure. I ordered another UPS, this one with pure Sine Wave output. If this new one doesn't have this problem, then I guess I will know it's the UPS that's bad..

 

[LTC8K6]

If the bathroom lights dimmed, then I think the mains voltage dipped...

 

[LTC8K6]

Possibly a circuit breaker or GFCI problem?

 

[Carfax83]

Could those things still happen in the dead of night though when everything's turned off and everyone is asleep?

Because it still does. Sometimes I go downstairs at night when my family is asleep, and I've heard the UPS making a clicking noise which causes the LCD to light up momentarily..

And the Cyberpower software has reported no instances of undervoltage or overvoltage after the UPS clicking..

Do you recommend that I get an electrician to check it out?

 

[LTC8K6]

If the bathroom light is dimming when the relay is clicking, then yes, I'd ask an electrician to check it out.

 

[Carfax83]

If the bathroom light is dimming when the relay is clicking, then yes, I'd ask an electrician to check it out.

One last question.. Is it possible that the dimming could be caused by the sudden surge of switching from AC to DC then back to AC in a second?

My PC uses on average about 225 to 250 watts when idling. Could the sudden demand for power trigger the dimming lights?

 

[LTC8K6]

One last question.. Is it possible that the dimming could be caused by the sudden surge of switching from AC to DC then back to AC in a second?

My PC uses on average about 225 to 250 watts when idling. Could the sudden demand for power trigger the dimming lights?

I would think that when it switches, it is isolated from the mains power?

If it's the computer load causing the dimming, then you should get the dimming when you turn the computer on. Take the UPS out of the circuit. Just plug the computer in directly, and see if turning it on causes the dimming.
2.5 amp load coming on should not cause dimming. If it does, you have a wiring problem somewhere.

You could also leave the UPS unplugged for a while, and see if your bathroom light still occasionally dims?

If removing the UPS gets rid of the dimming, then it's likely the UPS.

If not, then you have a wiring problem somewhere.

You could also have some other large load kicking on somewhere? HVAC system or a water heater?

 

[Spungo]

Possibly a circuit breaker or GFCI problem?

Not a chance. If GFCI or AFCI breakers detect a problem, they completely turn off, and they stay off until they are reset. GFCI wouldn't be very effective if they still allowed power to flow after a ground fault was detected. It only takes about 20mA to kill someone under the right conditions, and that's the reason they completely shut off.

One last question.. Is it possible that the dimming could be caused by the sudden surge of switching from AC to DC then back to AC in a second?

Possible, but very unlikely. Things like high efficiency motors have very high starting currents, but electronic devices generally do not. A large freezer will really screw with your voltages when the compressor turns on and off. Do you have any hard-starting motors running on the same circuit as your computer? Fridges, freezers, some furnace fans, etc? Anything related to air conditioning? Vacuum cleaners?

Grounding is another potential problem. The wiring in your house is probably fine since we have wiring laws in this country, but it's always possible for the grounding in a power bar or extension cord to be damaged in some way. I didn't know my parents had ground issues until I connected a UPS to their computer, and the UPS was reporting grounding issues. The power bar used to feed power to their computer and monitor had defective grounding. I don't know if it was always broken like that (made in China) or if it was damaged after years of general wear and tear.

If you don't already own one, you should buy a ground tester. They cost $10 and they last forever.
amazon.

If you just have a multimeter, set it to AC voltage and measure the voltage between the neutral and the ground. Neutral is the larger of the 2 prongs. Ground and neutral are the same electrical point, and current running through the neutral can cause the voltage to be higher than 0V, but it should still be very close to 0V. If you see something like 5V or 10V between neutral and ground, that means there is a grounding issue.

 

[DrDoug]

You might want to check the outlet. One of my customers had a problem with their APC doing this so I went and checked it out. When I got close to the outlet I could barely smell ozone, meaning there was an electrical problem at the outlet. It turns out the house was built with cheap commercial outlets (push in connects) and the hot line was losing contact with the outlet when it heated up a bit (load). I powered the line off, pulled the outlet out, powered the line back up and put a load on it. Not only could I smell the ozone but I also heard a slight buzzing as the connection heated up. I installed a good GE heavy duty outlet (screw connects) and the problem was solved.

He decided to go ahead and change out the rest of the outlets in his house for peace of mind.

 

[Carfax83]

Excellent suggestions guys. I'll take all of your advice into consideration. Spungo I'll make sure I get that ground tester ASAP and report back with the results.

So far I'm leaning towards the UPS itself being the culprit though. The reason why is because these clicks are so random. Some days I don't hear anything, and another it will go off once every few minutes throughout the entire day.

That's why I wanted to know whether the relays themselves could be malfunctioning or the AVR. Supposedly, it's not supposed to go into battery mode unless the AC utility voltage falls below 90v or rises above 140v.. And since I've been logging everything, it hasn't exceeded those boundaries a SINGLE time..

And I've had this particular unit for over 6 years now. I have a new one coming in a couple days, so we'll see how it reacts when I hook it up to my system.

 

[LTC8K6]

Not a chance. If GFCI or AFCI breakers detect a problem, they completely turn off, and they stay off until they are reset. GFCI wouldn't be very effective if they still allowed power to flow after a ground fault was detected. It only takes about 20mA to kill someone under the right conditions, and that's the reason they completely shut off.

A GFCI problem, not a working GFCI.

 

[Carfax83]

Sorry, forgot to update this thread..

One day before my new UPS came, which is this model with pure sinewave output, the strange clicking noise completely vanished

To this day I have no idea what was causing it, but it's definitely gone. Haven't heard squat from the old UPS (which I have hooked up to the UHDTV and other stuff in the living room), or the new one which is powering my new system.

In fact, I just recently learned that my PSU has the active PFC capability, and that I should have used a pure sinewave output with it from the beginning. When I bought my PSU a few years ago, I had no idea what PFC was at the time, so it never even occurred to me.

But the important thing is that the annoying noise is totally gone. Perhaps it might have been the battery after all? That's one thing I definitely changed, and the unit itself was about 6 years old at the time, so the battery likely needed changing anyway.

I still intended to buy that ground testing gadget though. That's something that strikes me as very useful.

 

[toyzrme]

I know this is an old thread, but wanted to return some value here - thank you to all previous posters for the education and insight.

I've had this happening for a few months now (random clicking of my UPS), and I think I've finally fixed it.

It was getting more frequent, but still came in bursts: i.e. it would click every couple of seconds for a minute or two or five, then stop for a while. Assumed this was the AVR automatically switching transformer taps to boost/buck the voltage back to 120v - but it was basically impossible to tell from the UPS' LCD screen, as it insists on rotating displays constantly, making it all but useless to actually monitor a parameter. Oddly enough (meaning FRUSTRATINGLY), the UPS software never showed under- or over-volts - so I assumed this was perhaps the UPS going bad/getting more sensitive. Or crappy software <eyeroll>

Then later in the problem's evolution, the fluorescent light plugged into the same circuit would sometimes flicker at the same time. So I put my volt meter on it, and clearly, the voltage was dropping - to 104 at the worst. Never over-volted. Checked other circuits, and plugged the UPS into other circuits: no joy - didn't see a problem.

Ok, out to the breaker box - SOMETHING is going on in that specific circuit, so let's start at the beginning and trace the power. Pulled the offending circuit breaker, and found some corrosion on the bus bar tab - AHA! Cleaned that up, a touch of dielectric grease to prevent more corrosion, replace the breaker. VOILA! No clicking, no lights flickering - 120-122v rock solid, even with load.

My guess is that there was a tenuous connection from the breaker to the bus bar, enough to handle light loads without drooping, but when various loads turned on/off, it would sag, at least momentarily. It probably also caused some arcing in there (YIKES), adding to the corrosion.

Hope this helps someone else in the future!