UPS VA Rating

I'd have to make an educated guess but from the logical POV it seems like those ratings apply to the battery buffered outlets only since the others are basically just extended, unbuffered wall outlets.

You'll find that whatever is connected to those ports shuts down if you pull the main plug on the UPS

-DG

seekermeister said:

When an UPS has both surge and backup/surge outlets, does the VA or wattage ratings include both, or only the ones that run on battery?

That depends on the UPS.

The VA ratings are not the same as the Wattage ratings ( strange as this may seem! VA is different to Watt. The VA specs are for complex power. Watt = real or active power.

You may find this of interest;

AC power - Wikipedia, the free encyclopedia

Uninterruptible Power Supply (UPS) FAQ

Regards....Mike Connor

seekermeister said:

Mike Connor said:

seekermeister said:

When an UPS has both surge and backup/surge outlets, does the VA or wattage ratings include both, or only the ones that run on battery?

That depends on the UPS.

The VA ratings are not the same as the Wattage ratings ( strange as this may seem! VA is different to Watt. The VA specs are for complex power. Watt = real or active power.

You may find this of interest;

AC power - Wikipedia, the free encyclopedia

Uninterruptible Power Supply (UPS) FAQ

Regards....Mike Connor

Different, but it seems that there is a ratio between them that is constant, so for all practical purposes they are the same.

They are not the same. Not in any way at all. There are no ratios or anything else similar between them. They use different SI. Units ;

http://en.wikipedia.org/wiki/Interna...ystem_of_Units

and are calculated differently.

1 W = 1 J/s.

1 Watt = = 1 Volt • 1 Ampere


A volt-ampere (VA) is the unit used for the apparent power in an electrical circuit.


Regards....Mike Connor

seekermeister said:

You may be right, but every 1000VA UPS that I have seen, always had 600 watts of power. It seems that this was true of other units also (in terms of a ratio), but I could be wrong.

The results are specifically dependent on the equipment,how much power it uses, and how it uses it. There is no "ratio" of Watt to VA. They are totally different things.

The three units concerned here are;

W ( Watt )
VA ( VoltAmpere)
var (Volt-ampere reactive )

Only effective power, the actual power delivered to or consumed by the load, is expressed in watts. Imaginary power is properly expressed in volt-amperes reactive.

While both the volt-ampere (abbreviated VA) and the watt have the dimension of power (time rate of energy), they do not have the same meaning. Some devices, including Uninterruptible Power Supplies (UPSs), have ratings both for maximum VAs and maximum watts.
The VA rating is limited by the maximum permissible current, and the watt rating by the power-handling capacity of the device. When a UPS powers equipment which presents a reactive load with a low power factor (e.g., a computer), neither limit may safely be exceeded.[3]


Quoted from; Volt-ampere - Wikipedia, the free encyclopedia


Regards....Mike Connor

I have a APC 750VA that is rated at 450 watts and this rating is for the UPS output only. It has 5 UPS outlets and 5 surge only outlets. Three of the surge only outlets can be setup to turn on/off by monitoring one of the UPS outlets marked Master. If it sees 0 power draw on the Master outlet it will turn off these 3 outlets. This feature can be turned off if not needed. At present all of my computer stuff (PC, LCD Monitor, Cable Modem, Router, Vontage Unit, Wireless Phone System) is on the UPS ports and I draw 148 Watts. I also have a scanner and when it is scanning I hit 170 Watts. We are always having power hits during rain storms my UPS system is great. I also have one on each of my TV systems.




Jim