APC Smart-UPS 1500VA Teardown

[@KaizerPowerElectronicsDk]

You can see the pictures or get involved in electronics yourself, from these links :) All pictures: kaizerpowerelectronics.dk/teardown/apc-smart-ups-1500va-teardown/ Discussion of the teardown: highvoltageforum.net/index.php?topic=2998.0

[@HomelabExtreme]

You missed a few points about this UPS. 1: As you later realized, the big "choke" is a transformer, and it has 3 taps on the high voltage side. These taps are used for voltage correction, as this UPS is "line-interactive", so in case of voltage highs or lows, it uses the transformer as an auto-transformer to boost/buck the incoming AC, without using the inverter. 2: This UPS uses a clever patent held by APC for a long time, where the diodes in the MOSFETs are used as a bridge rectifier to charge the battery during normal operation, and when the UPS is running, it puts the whole circuit in reverse, using the H-bridge to generate ~24VAC for the transformer, resulting in 230v out. 3: The two small "chokes" is in fact also transformers, these are 230/24v AC transformers and they provide the power for all the relays and the control circuits. It seems like kind of a relic, but APC still uses these unregulated transformers in their newer UPSes even though you'd expect that job to be performed by a SMPS today.

[@KaizerPowerElectronicsDk]

Thank you for chiming in with more details, I love learning new concepts :) The 24VAC transformers, was pure guesswork without checking the PCB tracks :o

[@r3tr0nic]

I have several of these, the newer version with LCD screens. Very nice units with sinewave output, and adjustable protection from mains being too high ot too low. Got them free from a company that had them as extras sitting around for too long that the batteries where shot. They did not want to buy batteries but just new units instead. These were not even used and like brand new. Added two large marine batteries and they have worked great. Eventually want to use some of my 280AH LiFePO4 batteries, but like everything APC, no schematics and lots of proprietary. I have heaps of APC transfer switches, PDUs and other products. Some are easy to reverse trace the PCBs. I just have to find the MCUs voltage sensing input circuitry and then potentially a correcting circuit can be devised to adapt [safely] for LiFePO4 batteries. Anytime I see anything APC in recycling/rubbish, esp the older vintage stuff, I grab... The components they use are quality.

[@KaizerPowerElectronicsDk]

I got 3 more APC UPS types in the teardown stack. From 1500VA to 40kVA!

[@SeanBZA]

Fuse is in wrong location, it is the link. Got the 750VA version, and it needed new batteries, which are now external, using that connector to power it.

[@KaizerPowerElectronicsDk]

So the external battery plug has two poles? They just looked to be pretty close with no separation.

[@SeanBZA]

@@KaizerPowerElectronicsDk No the 750 has an external battery connector, that one you have has a shipping link, you pull it to ship or store it, there is no external power option. Those wires will disconnect one of the battery leads direct from the battery. Needed because they do draw a small current even off and not plugged in, which will over discharge the battery. With a flat or dead battery they will not power on at all.

[@KaizerPowerElectronicsDk]

"Battery connector" is in my world, a place to connect a battery. It should have been labelled "Battery disconnector" :)

[@SeanBZA]

@@KaizerPowerElectronicsDk Link to connect the battery.....

[@KaizerPowerElectronicsDk]

@@SeanBZA APC be all like RTFM :D

[@arsalanqaiser797]

Any repairing video do u have

[@KaizerPowerElectronicsDk]

Not on these discarded units, that have been thrown around in the junk yard.

[@Wtfinc]

Do you think its a good business model to repair power electronics? Like solar inverters and amps n whatnot? Should I make a product? Could probably make some nice stuff once i get my math right

[@KaizerPowerElectronicsDk]

There is no good business in trying to repair the stuff I find at scrap yards. You will need to fetch it at the actual owners discarding stuff or having a defect. That supply chain is however very hard to break into, as most companies would call their UPS supplier and make a deal for a new one, where the old is discarded in the same proces. All this stuff is also so old, that a aftermarket for repaired units is quite small and maybe only limited to private market, which will not pay high prices. You can get lucky to find just that ONE business with a breakdown, needing just that ONE thing you have. But I can tell you from experience that I have been saving expensive stuff for 10 years waiting for that phone call, it just doesn't happen. Companies go to the big surplus companies that also have some kind of warranty on their repaired products.

[@trevorvanzuydam8115]

What is the lug between the ferrite coil and blue thing

[@KaizerPowerElectronicsDk]

On the right side of the blue-ringcore-blue, its the earth connection terminal to chassis. On the left side, which I assume you mean, in the white circle silkscreen. It's a lug used as a bridge, instead of the missing inductor, which is circle silk screen is for.

[@inothome]

I wonder if that was deemed defective after someone hooked up the batteries wrong? Looks like it bit you a few times too! Hate when that happens.

[@KaizerPowerElectronicsDk]

It is from the scrap yard, so no doubt defective :) Maybe. Some items are also just thrown from upgrades.

[@SeanBZA]

@@KaizerPowerElectronicsDk Likely tossed because a replacement battery pack from APC costs almost as much as the new UPS itself. But aftermarket batteries that size only cost a quarter of the price, so replacing them if you get it for free is a great deal.

[@inothome]

@@KaizerPowerElectronicsDk Wish I had a cool scrap yard like that near me!

[@brookerobertson2951]

Been thinking about getting one of these to use as an inverter.. you can get them very cheap but the postage cost as much as the UPS..

[@KaizerPowerElectronicsDk]

Even without batteries?

[@SeanBZA]

@@KaizerPowerElectronicsDk Half the weight is the batteries.

[@KaizerPowerElectronicsDk]

That was my point. Get one without batteries and its maybe affordable in shipping.

[@Wtfinc]

Why do you hve so many igbts/fets/bjts? Whatever they are. Maybe even half bridge rectifiers but id be impressed if they all transistors. I was so envious when i saw ur title card lol. Bet u can make some cool stuff with all them. Id make an inverter and tesla coil to start and then a fat audio amp, and a fatter radio amp if they fast enough. God i love electronics. Wish i got into the good stuff earlier in life. Wish i had taken my meds then too but… lol

[@Alexelectricalengineering]

Nice one 😁👍👍👍

[@Real_serdique]

Hello if you don't mind do you still have it?

[@KaizerPowerElectronicsDk]

It is all recycled properly as electronics and iron scraps :)

[@Real_serdique]

@@KaizerPowerElectronicsDk well okay I thought you might still have the scrap because I really need it...

[@xenoxaos1]

3:08 it was done so they don't turn on in storage

[@KaizerPowerElectronicsDk]

Good point :)

[@Wtfinc]

Why do you hve so many igbts/fets/bjts? Whatever they are. Maybe even half bridge rectifiers but id be impressed if they all transistors. I was so envious when i saw ur title card lol. Bet u can make some cool stuff with all them. Id make an inverter and tesla coil to start and then a fat audio amp, and a fatter radio amp if they fast enough. God i love electronics. Wish i got into the good stuff earlier in life. Wish i had taken my meds then too but… lol

[@KaizerPowerElectronicsDk]

Hundreds, if not thousands, of MOSFETs and IGBTs by now :)