Teardown - Poweraware PW9305 - 3phase 415V UPS 30KVA 21KW - Page 1
Forum section: electronics / testgear

author: TerraHertz
author_rank: Super Contributor
timestamp: April 11, 2018, 03:30:22 pm
content: Here's that big UPS I had some troubles picking up. I'd won it in a Pickles auction for ONE DOLLAR (sole bid), and the company selling it were not happy. They'd forgotten to put a reserve price on the listing, due to being too busy setting up auction of everything in a vast factory in Albury.For a while they were insisting "To trace, disconnect, tag and load 9074 onto your transport, the cost would be $965.25"Previously discussed here:https://www.eevblog.com/forum/chat/having-some-trouble-retrieving-my-property-request-for-comments/Anyway, I was able to overcome the resistance. Drove down to Albury area on Monday, camped overnight in the bush, then turned up (as arranged) on Tuesday morning at the factory. I'd expected to have to do everything myself - demounting and moving it, etc, but found the staff there had very helpfully already done the disconnecting and moved it to the loading dock. Even helped me lift it onto the trailer. So I really did get it for $1. (Plus costs of a 1096 Km 2 day round trip.)So here it is. A preliminary look at the insides.Not trying to make sense of it yet. Just glad to have got it home, successfully offloaded it from the trailer, set it upright, etc. The electronics rack weighs over 200 Kg, and the center of gravity is way up near the top, due to the bottom half of the cabinet being empty space for batteries. For a different version. Mine has a separate battery cabinet.

author: BrianHG
author_rank: Super Contributor
timestamp: April 11, 2018, 04:30:02 pm
content: SSSSSSSWWWWWWWWEEEEEEEEETTTTTT!!!!!!Will you destroy it for parts, or, actually use it to give you backup power for your entire house + supply all the houses on your block when the apocalypse comes?

author: rsjsouza
author_rank: Super Contributor
timestamp: April 11, 2018, 05:29:33 pm
content: Congratulations, Terra! All these electrolytic capacitors aligned are really beautiful.Have fun disassembling or restoring it!

author: TerraHertz
author_rank: Super Contributor
timestamp: April 11, 2018, 05:31:16 pm
content: It's intended to be backup power for my home and workshop.But hopefully with solar charging of the batteries. Which I hope can be Li-ion rather than lead-acid.So maybe there will be some modifications. Depends on how well reverse engineering it goes. 'Pretty sure' I won't be able to get schematics and code source from the manufacturer.One disappointing 'feature' is that it uses two separate battery strings to supply + and - to the choppers.

author: nctnico
author_rank: Super Contributor
timestamp: April 11, 2018, 05:40:26 pm
content: If you go for Li-ion then make sure not to use bare cells but have a BMS in between to keep the cells happy.

author: TerraHertz
author_rank: Super Contributor
timestamp: April 11, 2018, 05:48:30 pm
content: Absolutely! BMS also with cell leveling.This is why the 'two battery strings' detail is annoying.Even if I do use lead acid, I'd want a cell leveling and diagnostics system.This UPS is meant to be the starting point for a series of experimental adventures.

author: MadTux
author_rank: Frequent Contributor
timestamp: April 11, 2018, 07:01:48 pm
content: Nice find.Probably also useful to power machines that briefly need lots of power (lathe during spinup, big TIG welder) and you have a small fuse at your house.

author: Hydron
author_rank: Super Contributor
timestamp: April 12, 2018, 08:07:08 am
content: Thanks for the pics, I have a few PCBs etc from one of these machines and it's nice to see how they fitted together in an intact one.

author: TerraHertz
author_rank: Super Contributor
timestamp: April 12, 2018, 12:58:32 pm
content: Quote from: Hydron on April 12, 2018, 08:07:08 amIf there's anything specific you want better photos of, PM me.Otherwise the UPS will now sit in my storage shed for a while, as I work through other more urgent projects. Though in the meantime I'll be trying for some more info from the manufacturer.Edit to add:Here's a few other bits that came with it.* Mains supply filter and surge protector cabinet.* Isolator CB for the two battery banks.* Supply side source selector (Mains vs a generator set. Contactors are electrically interlocked, to enture never both on at once.)* UPS bypass switch.

author: edpalmer42
author_rank: Super Contributor
timestamp: April 12, 2018, 02:06:12 pm
content: Depending on how long 'a while' turns out to be, you might consider getting the batteries on float charge. They've probably been off charge for a while now and, if left for too long, might suffer. Lead-acid is quite tolerant of being left idle, but still....Ed

author: TerraHertz
author_rank: Super Contributor
timestamp: April 12, 2018, 11:08:15 pm
content: Yes, but...The factory closed down 4 years ago. The UPS had been unpowered since then. At that time the battery cabinet had been emptied, for safety reasons. Except whoever did that was in a rush, to judge by the state it was left. They had skipped emptying the last, bottom battery tray. So there were still 6 out of 36 original batteries present.They are in varying states. One still has 12V, the lowest is around 1V. But they are not sulfation-swollen yet. I'll try giving them a charge, see how they go. Don't expect much.That's on today's list.

author: nctnico
author_rank: Super Contributor
timestamp: April 12, 2018, 11:45:28 pm
content: In my experience lead-acid batteries which where left for a while are toast. You might be able to charge them but the capacity will be nowhere near the original capacity. Going for Li-ion sounds like a better plan but the problem will be that the (remaining) charge prediction won't work at all if that prediction is based on the battery voltage.However a Li-ion battery BMS is likely to have a Coulomb counter based charge gauge so if you can read that you might be able to build a lead-acid charge-voltage simulator.

author: TerraHertz
author_rank: Super Contributor
timestamp: April 13, 2018, 01:25:49 am
content: Quote from: nctnico on April 12, 2018, 11:45:28 pmI don't have much experience of lead-acid battery maintenance, but generally agree.One question: is your 'nowhere near original capacity' including use of a charger with de-sulphation zap cycles built-in?QuoteAgree. How this works out depends on whether I can reverse engineer the UPS enough to modify the firmware. If not, then I'd just ignore the UPS's opinion on battery state, and use the BMS for that information. So long as the UPS keeps operating, who cares what it thinks.Remember this UPS needs TWO separate battery banks, so whatever I do with batteries, I have to do twice.QuoteSee above. I wouldn't bother to fool the UPS. Just give it a 'healthy battery bank' DC voltage. It's unlikely I'd use the UPS internal battery charger, unless I can modify the firmware to do what I want.One of the main objectives with this, is to develop my own BMS. I have some non-standard requirements, related to a different project.Another thing to look into, is a converter from one DC supply (with more flexible voltage range) to the + & - HV DC rails the UPS requires.The battery voltages this morning were:12.8512.1011.9811.944.470.63Poor Mr Zero-V is currently getting a long de-sulphation cycle.

author: edpalmer42
author_rank: Super Contributor
timestamp: April 13, 2018, 03:03:14 am
content: Quote from: TerraHertz on April 12, 2018, 11:08:15 pmOkay, they're dust.Don't even bother messing with them. A 12V lead-acid battery that isn't 12V will never be usable. You'll probably find that even if you measure 12V, it'd be like trying to use 12V worth of alkaline D cells.You'll want to start with good, matching batteries, particularly at those power levels.I've thought about using Lithium batteries as standby batteries, but it looks that you have to step carefully. Trickle charge is out - Lithium hates it. But if the (required) BMS says that the batteries are charged and disconnects them, what will the UPS do? "My batteries just disappeared!!!". Alarm? Shut down? Refuse to transfer to the batteries on a power failure? Go crazy?? I doubt if you'll be able to separate the charging functions from the UPS. Reverse engineer? What's the value of your main battery fuse/breaker? What's the voltage of each string? 30KVA - 21KW. Are you really sure you want to mess with that? It won't release the magic smoke, it'll eject it at supersonic speed - complete with shrapnel!Ed

author: TerraHertz
author_rank: Super Contributor
timestamp: April 13, 2018, 06:38:48 am
content: Quote from: edpalmer42 on April 13, 2018, 03:03:14 amWell, see above. Four of them are 12V, two are sub-6V.I'm not proposing to use these with the UPS. Mostly because if I was going to use lead-acid for it I'd have to buy 48 new batteries. Mixing in four aged batteries would be ridiculous.I have other uses for these. Mainly my car-camping solar system, which presently uses a 12V 70AH lead acid battery, that weighs 24Kg. These 40AH ones are a much more convenient size and weight.QuoteTwo battery strings, each nominal 288V. I'm fully aware what a bomb that is.As for reverse engineering - we'll see. 1st question, can the code be extracted? Likely to be readback blocked. I don't even know the CPU type yet. Also there's a lithium cell on the control board, that appears to be flat. Not sure I had access to both terminals when doing a quick preliminary check.If it is flat, did the system lose any critical data? Like for instance a manufacturer/agent authorization code? The installation manual insists the system must be commissioned by an authorized agent. Did they _enforce_ this?

author: edpalmer42
author_rank: Super Contributor
timestamp: April 13, 2018, 02:40:24 pm
content: Quote from: TerraHertz on April 13, 2018, 06:38:48 amHave you considered inquiring about the cost of having it officially recommissioned and what exactly is included? An extended warranty might be worthwhile on a system like that.Ed

author: TerraHertz
author_rank: Super Contributor
timestamp: April 13, 2018, 10:33:18 pm
content: Quote from: edpalmer42 on April 13, 2018, 02:40:24 pmHeh. No. That's a highly undesirable path. Partly because I'm cash-poor to an extent that few here could comprehend (very unusual life situation) and certainly couldn't afford it. That was why I went to a lot of trouble to avoid paying the extra fee the owners wanted after they realized I'd won it for effectively nothing.The only thing I hope to get from the manufacturer is a copy of the PC remote management software. The seller was unable to locate the CD that should have come with the UPS. The UPS can run stand-alone, but it would be nice to have that software.In any case, my plans for the UPS are flexible, and include using it for self-education in high power mains generation. The options tree depends on how far I can go with reverse engineering it, and some end results involve it being significantly modified.Other possibilities of course, involve me accidentally ruining it beyond repair. Hopefully not. That would be sad, but then it did cost $1.One thing I particularly like about this UPS, is the transformerless design. There's nothing in it that I couldn't reproduce same or similar. The ultimate goal is an open-hardware, modular mains power generation system. That can be easily manufactured in any small workshop. Part of a long term project of mine.