ups from junk yard

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about 2 years ago me and my mate came across a junkyard. some business had just upgraded there office's and dumped all the old equipment at this junk yard. the things that cought my eye were the UPS's:thumbup:(load shedding was its peak:p) i bought a few for dirt cheap. the batteries were finished but they worked like charm. long story short... i am using one to back-up my new/first tank.:thumbup: i bought a 52 amp hour deep cycle battery, wired it up and vwalaa! a pic follows......

if anybody needs helps with wiring ups's, relays, inverters, etc im open;) i just started marine so i dont know much about that yet:p so stick to electrical questions:)


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Nice DIY!! Have perhaps got a wiring diagram to share?
thanks:)

well for this setup there isnt much of a wiring diagram.
you see that UPS was once a pc UPS with a small battery inside to run a pc for about 20 mins so when the power goes out you have to save your work and shut down safely. i simply reaplaced that battery with a big battery to run for a few hours. the ups has a 220v in and 220v out. all the circuitry is inside and untouched.
 
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Nice! Great DIY idea.
 

Awvince

Here fishie fishie
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I've read that pc ups's tend to burn out there pc boards when they run for long periods of time, any comment?
 
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I've read that pc ups's tend to burn out there pc boards when they run for long periods of time, any comment?
you may be right awvince. i suppose depending on the make etc. i have my moms whole office running on a 1800w ups which i got from the same junk yard and i put 2 105 amp hour batteries on it and ran my moms office for 2 hours during load shedding everyday for about 3 months and its still there working. but now load shedding is gone. lol:thumbup:

a lil more in depth:
this ups had a fan blowing on the heat sink of the transistors which produce the 50hz signal. the transistors are probably the first things that would go due to overheating or the step up transformer. the fan kept everything cool. if your ups doesnt have a fan and you want to do this mod. pun a fan in:)

since i got them for next to nothing and they needed new batteries anyway. i got nothing to loose. i would not go out and buy a ups to do this though. too expensive.
 
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Very true, just compare the heat sink on a UPS and inverter.
yea normally an inverter uses its whole casing as a heat sink. thats alot of heat sink! but modern inverters do not use a step up tansformer as such. they use a thing called a switch mode circuit. ALOT more transistors in these circuits. therefore they need big heat sinks

but as long as you have fan blowing on it should keep the tranistors quite cool.:thumbup:
 
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Hey brett

Well funny thing I found a small ups in my mothers garage(was probably one of my brothers ups)any way its mine now.

Was gonna buy a small battery on monday wanted to see how long it(ups)will run my return pump.

So did you just connect the big battery in place of the old small one?How do you charge the big battery?
 
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you right shaun they not designed to run for long times, also some are, but most are not. the main concern is over heating though. if you add a fan inside then it should be fine. like a said earlier in the thread, the things that will blow are the transformer, if there is one, and the transistors. they will blow due to over heating. so just keep them cool. and also given the load that theyt running. with fish tanks. its not much normally.

mine has been going for a very long time. if you got one for free and needs a new battery, you got nothing to loose really.

about the charging. you use the same circuit to charge big and small batteries. it just takes longer to charge bigger batteries. they dont need a bigger voltage or current:)
 

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