Can a APC Smart-UPS XL Modular 3000 VA 230V system be used to provide DC

[McQ_apc]

This was originally posted on APC forums on 2/23/2009

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I'm replacing a server with a ruggedized PC that runs on 48 V DC. Is it possible to use the existing UPS to provide this by bypassing the inverter on the output side or would it cause a problem? McQ

[NoMoreJuice_apc]

This was originally posted on APC forums on 3/1/2009

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Hmmm.
"bypassing the inverter on the output side" defeats the whole idea of an AC power UPS.
By doing this, you would essentially be left with a battery and a charger. Besides, AFAIK no UPS would pass the self-test if you disconnect the output transformer.

I "think" APC has some DC equipment, designed for 48V.

But: In terms of "off the shelf solutions", I would think along the lines of:
1) A battery string with 48V.
2) A simple 55-60V charger that can BOTH supply the load AND charge the batteries in case they are empty.
3) A decent solar charge controller that regulates battery charging as well as providing a low-voltage-disconnect to the load in order to protect the batteries.

I think that there are several manufacturers of solar controllers out there who make equipment that can be monitored remotely.

So far for my 2 cents.

[tdowningtimotheus_apc]

This was originally posted on APC forums on 4/5/2009

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AFAIK, you need marine cycle batteries, rather than automotive ones... Automotive batteries will degrade quickly when used for long discharge cycles, because of compromises made in order to get the short rush of high-amperage current needed to start a car.

[BillP]

This reply was originally posted by Angela on APC forums on 2/24/2009

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i havent heard anything about anyone rigging anything up like this but APC cant recommend that you open the unit and modify it to do something like this, as an official answer. maybe someone else will chime in with an unofficial response/recommendation.

[McQ_apc]

This was originally posted on APC forums on 2/25/2009

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Thanks -- I'll probably have to fiddle around and test it on my own. Basically I've got some big servers out there in extreme conditions and they keep failing. So I'm installing some low-power military quality rugged systems to replace them. But the new systems use DC (48 V). So I'm looking for a field expedient to keep things running for the next few months until we can come up with a longer-term solution. McQ

[McQ_apc · Accepted solution]

This was originally posted on APC forums on 3/3/2009

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We had considered using 4 car batteries with a transformer and rectifier. But part of our concern is that we already have the APC equipment in place and until we come up with a long-term solution, we want to provide a temporary approach to provide power to the new server -- which runs on DC and is replacing the old AC-powered server.

We'll do some testing on the bench with a spare UPS and get back with a report on the results.

McQ