What's inside an APC SmartUPS VT 20kVA?

[@DoogieLabs]

Just a heads up the index isn't applying to the video time base, one thing that has helped me ensure that it works correctly is always starting the introduction in the index from 0:00.

[@AintBigAintClever]

I thought it was just a processing delay. I've just gone through my last 120 videos, adding 0:00 Index to each, well, index. It's now updated the timeline for each of them. Cheers for the heads-up!

[@DoogieLabs]

Thanks for sharing the teardown! I feel like placing the fan connector closer to the edge of the board and using a 90 degree connector (or designing the option for both) would have definitely been the way to go. Loads of good "fun" parts in there.

[@saeedahmed973]

Batt Temperature Exceeded Upper Limit. my problem pizza halp

[@andrewsweet43]

I had the same problem while trying to cold restart the same model UPS some years ago. It didn't respond to button presses, although the batteries were charged AND the AC power was available. Also nothing was mentioned on the user's manual about that situation. We dissasembled the unit, to take a look inside expecting blown IGBTs or something, and it was then that i spotted the little microswitch behind the little unmarked hole. We thought why don't just press he switch with the module plugged in? We had already arranged to replace the module by an APC certified technician anyways the next day. AAANND viola! the UPS came back to life and works flawesly since then....

[@AintBigAintClever]

I ought to have rewatched my 40kVA teardown video before filming this one, although first time round it appears I didn't spot the button. Hopefully the mention of it in the index will be enough for Google to point other would-be cold-starters in the right direction.

[@mohamedfaizal2325]

Nice I need step by step what trouble shooting

[@sparkyprojects]

If it's like a VFD, the control circuit is across 2 phases, and will probably have a low voltage cut out, so like you said, you would need 400v. I had a small APC (domestic size), but didn't want it to be powered constanlty, but that wouldn't cold start either.

[@AintBigAintClever]

The Back-UPS ones with a single button I don't think could cold-start, but Smart-UPS I've managed to do either by pressing and holding the on button or pressing and holding both. I also managed to get an old Smart UPS 600 to catch fire by tapping a set of pliers across two of the heatsink fins, near the battery retaining bracket, but that's another story :)

[@sparkyprojects]

@@AintBigAintClever Half bridge where each heatsing is connected to the power rails ? Ouch I was working with a XP Power guy checking a rack mount UPS (really nice units), i tested the voltage on a slide in battery pack where the terminals were only 1/2" apart and slipped, it caused an arc so we had to throw it outside the building :D

[@AintBigAintClever]

@@sparkyprojects no idea what the setup was, but there were I think four heatsink blades in there and I was curious (it was old) as to what would happen if they got inadvertently shorted whilst refitting the battery bracket (it was a shit design where if you fitted the bracket you couldn't plug in the batteries but if the batteries were plugged in you risked shorting it out). It sparked, then a few seconds later one of the MOSFETs decided to just catch fire. Out the door it went. I've also had an MGE Pulsar start smoking just after I'd replaced the batteries in its external pack. Had to yank all the leads and get it out of the server room before the smoke alarms caught a whiff of it.

[@theirisheditor]

I have a 230V APC Smart-UPS 1000 from 2004 (former workplace server UPS). This one cold starts by holding the power button for a few seconds. I need to cold start it before connecting the mains AC, otherwise it trips the RCD.

[@mnelson10000]

Interesting, thanks for sharing. I wonder what the logic was behind sticking with their little lawnmower batteries... it looks as though there's enough space to accommodate car/boat size batteries.

[@AintBigAintClever]

They can go for the "transformerless" design by using a high voltage DC bus and (presumably) running it as a big 50Hz (or 60Hz) power amplifier, also it lowers the current involved (a 40kVA UPS with 48 volt battery strings would be pulling over 800 amps, this design drops that to more like 100 amps which is much more manageable).

[@mnelson10000]

@@AintBigAintClever That makes sense, but 24v marine batteries are readily available and it looks like there's plenty of room to string several in series to create high voltage rails. I wonder if it's more about the economy of sticking with a universal size in all of their units?

[@AintBigAintClever]

@@mnelson10000 I think our pair of Riello Multi Plus UPSes use larger batteries, but they're not user-replaceable, they're an engineer job.

[@RixtronixLAB]

Nice video, thanks :)

[@eduardomoscosov.8086]

Hi, when the unit don´t start, not signs of life, I suppose that the power supply is bad, but I checked all fuses and not bad (open). Maybe the thermistors? One is in continuity and the other not. I did not find datasheets of them. can you help?

[@johnkato3038]

Can i remove batteries when the ups is running? Is it okay plaese?

[@Brian_Of_Melbourne]

Is there any hint that the UPS world will move from LeadAcid to Lithium or is that just not economical?

[@AintBigAintClever]

APC do some Li-Ion units (SMTL models), but generally the main advantage of Li-Ion as far as I can tell is weight, which is less of a concern in UPSes compared to, say, cars.

[@MAYDAYDEEJAY]

I take it at this time everything is being scrapped ? I would really like to buy the power modules... I was a little bit to late few Years back with Your previous video, maybe this time I'm not to late ?

[@AintBigAintClever]

Message me through Facebook, I'll see what I can do.