APC UPS units - troubleshooting

[DanielCoffey]

Re: APC UPS units - troubleshooting

Good point. It has never been run down except once when new.

The catch is that I don't have a suitable load that I can put on it for a long period of time that will be constant as we have gone all-LED on our lighting here. I will have a rummage and see what I can find that will be around 500W and see how it responds to a Calibration before going further with warranty calls.

[stj]

Re: APC UPS units - troubleshooting

how often do you cycle-test it?

you need to run a ups down a few times a year atleast - preferably monthly in order to keep the batteries internally stable.

[DanielCoffey]

Re: APC UPS units - troubleshooting

Thank you - I will stick with the original sized battery pack on the SMT1000I.

If I may ask a different question about some odd behaviour that my in-warranty 2017 (week 28) SMT1500I is showing as APC are closed for the holidays at the moment...

The SMT1500I batteries are the original ones inside the UPS which was bought in September 2017. The whole UPS was supplied by APC themselves direct to me. While I believe the UPS itself is under warranty still, I am not sure about the original batteries.

When running on mains, the unit appears to function and self test correctly. When switching to battery in a power outage the unit does something unexpected. The % charge indicator drops rapidly within 60 seconds from 100% down to 76% then slowly recovers to about 83% by 90 seconds. This is with a 200W load. Afterwards the charge indicator slowly decreases correctly in line with the load and time.

Would I be correct in thinking there might be either an issue with a bad cell in one of the batteries or might the unit need recalibrating? The battery pack does not show any swelling or leakage.

[Behemot]

Re: APC UPS units - troubleshooting

Those were likely the close to 2 decades old platforms, SU1000I.

The boards are pretty much the same for 1000- and 1500VA units, but the fan circuitry incl. the connector are missing for 1000VA units, you'd have to fit everything in. They have smaller capacity accumulators though so they won't pass such an energy (incl. losses) as the 1500VA version.

Mods I do on old units are improving better heat transfer from the board and transformer, but it's not necessary if you stick with 12/15Ah accumulators (otherwise with some small changes it does fit 17/20Ah ones, where the cooling improvements are needed for safe operation for longer runtime on battery).

[DanielCoffey]

Re: APC UPS units - troubleshooting

Thank you - I will take the opportunity to replace the small caps at this time then.

Assuming I don't spot any discoloured resistors or any visible signs of heat, is there any other preventative maintenance I could do at the same time? For example I have read on the forum that on some models there are a couple of resistors that are a little underrated for their workload and need replacing with a higher wattage standing off from the board?

Since this is an SMT1000I without a fan, is it possible to easily add in a fan? The case has pre-drilled holes on both sides and the SMT1500I that I also use has the fan fitted. I don't know if the SMT1000I has a fan header or not.

[Behemot]

Re: APC UPS units - troubleshooting

Nine years, I'd do it this time replacing the accumulators.

Voltage won't tell you anything when it's running, even if acting only as capacitors, they'd read correct voltage as the charger constantly feeds them. If the unit detects high ESR or way too short runtime under periodic runtime test (unless you turned that off), than it reports them bad, but that does not always has to occur and yet they could be pretty much dead.

You can try hooking something with high power draw on it, like some incandescent lamps or a hair dryer and than checking runtime. If it dies in a minute or so, time to replace soon, if within seconds, time to replace right away

[DanielCoffey]

Re: APC UPS units - troubleshooting

From your experience of APC UPS units, after how many years of light use of a SMT1000I would you consider replacing the 22uF caps?

I have a 2010 (week 44) SMT1000I that I have owned since new. I think it is just coming to the end of its second set of APC batteries as the runtime is not what I was used to. There is no sign of bulging on the batteries and PowerChute reports 27.5V on the batteries when the unit is on mains under light (15%) load.

[felix]

Re: APC UPS units - troubleshooting

Hello, I have 2x SRT10KXLI units, one of which shows Critical alert : Bypass Voltage not in range ; Low Voltage.

I have also attached a photo of the connections in the back of the unit (3phase) also showing the bypass jumper bar installed in place.

I have measured in both ends of the bypass jumper bar and there is normally 218V in both ends ( on top of screw ).

UPS firmware was updated through USB ( device ID went from 1002 to 1014, FW from 02.1 to 04.7).

NMC firmware is 6.0.7 version (AP9537SUM module) (did not update this).

Tried several times to turn off, alter settings etc. Even "braindeading" the unit , as described in this discussion.

I have also attached the Data log, showing Vmin and Vmax as zero.

Battery modules have been replaced on February (2 months ago).

Thank you in advance for your support and your help.

George

[kc8adu]

Re: APC UPS units - troubleshooting

4v= beyond dead.
stick a fork in it.

[Zot]

Re: APC UPS units - troubleshooting

I'm thinking the same - the battery doesn't even light up my charger - 12 hours and still at 4V - open short, I suspect.

Not a total loss, though - I found this really cool site

Thanks guys.

[jondoe]

Re: APC UPS units - troubleshooting

Some units require a battery to work, some don't and are hot swappable. Those ones are pretty cheap so I'd imagine it just needs a decent battery.

[Behemot]

Re: APC UPS units - troubleshooting

It's usually off with dead battery.

Most of the UPS keep the CPU in low power mode but they still draw some current (though very small). But keeping it off grid for more than half a year is just too long. Either recharge it every couple months, or remove the battery and recharge it once or twice a year.

[Dumah Brazorf]

Re: APC UPS units - troubleshooting

Nope. If the battery is totalized upses usually play dead.
Change the battery.

[Zot]

Re: APC UPS units - troubleshooting

My APC BE500R UPS is much smaller than some of those shown here... It has a single 7.2A 12 V SLA battery.

It's been sitting unused since we moved house in June last year.

I went to plug it in today and it shows no signs of life - the power LED doesn't come on.

There's definitely power at the end of the lead, the thermal shut-off is closed and power gets to the main board.

It was working when we packed it up, back in it's original box.

The battery is toast - reading 4v. I will put it on my smart charger and see if I can resurrect it But...

Shouldn't the LED light when power is on, even if the battery is done in?

I'm new to this electronics lark, but know my way round a multimeter... and armed with 'How to Diagnose and Fix Everything Electronic', I'm willing to have a go - but if there are some FYIs with APC consumer UPS's, I'm all ears.

[Behemot]

Re: APC UPS units - troubleshooting

Nah it was for budm, there is this game when two ppl say the same at the same moment, the first one who calls the other to pay the beer should get one

You can try dropping the voltage with a few diodes in series with the regulator input, though there is not too much space inside. And also I just realized there is no capacitor between the diodes and the regulator to smooth it's input? In that case the regulator is also stressed with smoothing the rectified spikes.

[paulzak]

Re: APC UPS units - troubleshooting

So sorry about the head ache. Take care of yourself. Absolutely will buy the beer when I get to Prague or you get to California. P

[Behemot]

Re: APC UPS units - troubleshooting

At 24 V, it has to burn down over 10 V (to about 13.8 V), at 1 A that equals 10+ W. With no heatsink you can imagine how hot the TO-220 package was getting.

edit: yo bud, you pay the beer m8

as soon as I get better, with my current headache that would kill me, oh my

[budm]

Re: APC UPS units - troubleshooting

24Vin and 15Vout so the Vdrops on the regulator will be = 24V - 15V = 9V, so if the batteries is really low and being charged if the charging current is lets say 1A, the IC will have to dissipate 9V x 1A = 9W, so yes, it will get really hot at the beginning of the charging and may go into thermal shutdown, or if the batteries have shorted cells, that will be bad also.
Heat sink needed and should drop the input Voltage.

[paulzak]

Re: APC UPS units - troubleshooting

At 24v in, I thought it was a little high but within range of the regulator's capability. I have been learning how inefficient these chips are especially when the input and output voltage is large. I pretty much decided that there was a small on-board transformer supplying 4 diodes to rectify the AC and that was it. If there was a mechanism to reduce or fine tune the input voltage to the regulator, I couldn't figure out where it was. You mentioned how crude these things were in a previous post and I'm inclined to agree. (Which in my case isn't a bad thing or I wouldn't have a hope of shooting this thing!)

Should I be looking for something upstream of the regulator or does this sound like it's working as intended?


Thanks for your interest and comments.

Paul

[Behemot]

Re: APC UPS units - troubleshooting

What's its input voltage?