Run UPSs in parallel?

fleabag

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Oct 1, 2007
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First I want to know if you can run power output (like a battery) that is Alternating Current in parallel. Secondly, I wanted to know if it were possible to run multiple UPSs in parallel so that you can run a higher load than if you had them running individually.
 

Blain

Lifer
Oct 9, 1999
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All UPS units are run in parallel. Unless you're talking about splitting a power cord so one wire is run through one UPS and the other wire through the second UPS.
They aren't built to be run in series.
 

Modelworks

Lifer
Feb 22, 2007
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Batteries are DC voltage. You can use multiple UPS to run all your equipment, like monitor on one , pc on another. But you cannot ever let the voltage output from one, connect to the voltage output of another.

If you mean connecting the output of one UPS to the output of another UPS , like on the same power strip, then NO, it might appear to work fine , until the UPS switched to battery, then it would likely go up in smoke.
 

Blain

Lifer
Oct 9, 1999
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Originally posted by: Modelworks
If you mean connecting the output of one UPS to the output of another UPS , like on the same power strip, then NO, it might appear to work fine , until the UPS switched to battery, then it would likely go up in smoke.
Did you mean to say... "input of one UPS to the output of another UPS"?

 

Modelworks

Lifer
Feb 22, 2007
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Originally posted by: Blain
Originally posted by: Modelworks
If you mean connecting the output of one UPS to the output of another UPS , like on the same power strip, then NO, it might appear to work fine , until the UPS switched to battery, then it would likely go up in smoke.
Did you mean to say... "input of one UPS to the output of another UPS"?

Nope.
That would be series. He said parallel where two outputs would be joined, hot to hot, neutral to neutral and then connected to a device. That would work as long as the power remained on, but the second you went to backup/battery it would be one ups feeding into another. The UPS regulation would go nuts.
 

Paperdoc

Platinum Member
Aug 17, 2006
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The answer is definitely NO! Any UPS keeps its internal battery charged from the AC wall supply and monitors that supply. When it fails, the UPS starts generating a 60 Hz AC output from its own oscillator and amplifier/regulator. But it has no way to synchronize that operation with another to make two units' outputs match at all times. So, as others have said, connecting two units' outputs in parallel will surely result in each one's shorting out the other within a very few seconds. A dangerous and expensive mistake.
 

Blain

Lifer
Oct 9, 1999
23,643
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Surely he's NOT asking if two UPS units can be "spliced together" at the outputs... Is he? :shocked:
 

Modelworks

Lifer
Feb 22, 2007
16,240
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Originally posted by: Blain
Surely he's NOT asking if two UPS units can be "spliced together" at the outputs... Is he? :shocked:

I think so.
I think he is thinking like if you needed to power 500 watts, could you use 2- 250watt ups connected to the same power strip.
 

Blain

Lifer
Oct 9, 1999
23,643
3
81
fleabag,
It's time to come clean with what kind of stunt you want to pull.
Be very graphic so that we can follow. :roll:
 

fleabag

Banned
Oct 1, 2007
2,450
1
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Originally posted by: Modelworks
Originally posted by: Blain
Originally posted by: Modelworks
If you mean connecting the output of one UPS to the output of another UPS , like on the same power strip, then NO, it might appear to work fine , until the UPS switched to battery, then it would likely go up in smoke.
Did you mean to say... "input of one UPS to the output of another UPS"?

Nope.
That would be series. He said parallel where two outputs would be joined, hot to hot, neutral to neutral and then connected to a device. That would work as long as the power remained on, but the second you went to backup/battery it would be one ups feeding into another. The UPS regulation would go nuts.

This