Electrical/UPS question

[M A V I C]

What's the easiest way to tell?

[Racer X]

Maybe I can take a quick peek tonight. Otherwise, at the top of the panel, with the door open to show the breakers, the main master breaker at the top, probably horizontal, should be labeled with its capacity. I'm guessing 125. if you are lucky, 200.

Some people may have higher Peak loads, but becasue of your home office, you may have a reasonably high average load when you are home and all the gear is running.

[cbelt3]

Racer- the ampacity standards are . IMHO, based on 1970's vintage 'typical' electricity usage. Builders rarely go 'over' code requirements, so y ou can bet your bottom dollar that the design is right at the bottom of what was to code in 1993 when MAVIC's house was built.

MAVIC, you should have a 'main ' circuit breaker at the top of your box. the rating on that is generally the rating for your box. That and the little sticker on the inside of the door usually says what the rating for the box is. If you have two boxes, one of them is the main and the other is the satellite box- each box will have its own rating.

The fact that you have 20 amp breakers SHOULD mean that you have 12 gage wiring. However.... Most houses installed 20 amp breakers and 12 gage wiring, but put in 15 Amp outlets because more than one outlet was serviced by the single breaker. Can you safely put in a 20A outlet just for your big UPS ?

Yeah, probably. I'd do it, and depend on the breaker to pop if there was an issue. Besides, your UPS may be rated at 13.3 Amps, but you're not going to use all that juice, are you ?

[M A V I C]

There isn't a main breaker in this box.

I'll see if I have a pair of wire cutters around here to measure the gauge of the wires coming out of the wall.

[quote cbelt3] Besides, your UPS may be rated at 13.3 Amps, but you're not going to use all that juice, are you ?
There's nothing else on that circuit when I plugin the UPS. Even with the UPS off, it still trips the GFCI.

[JoeH]

Inrush current is probably the cause of tripping the GFCI. Even though the steady state maximum output listed for the UPS is 1600 W, the input side will be higher due to less than 100% conversion. It probably can briefly draw as much as 3000 W or more when it first starts after you turn it on or plug it in. Even at steady state you do not want this on a 15 A plug or circuit, I have seen this model trip 25 A breakers. It really is happier on a 220 V circuit with a 15 A breaker. APC did make a 2200 VA model designed to go on a 15 A 110 V circuit, but discontinued it the last time the codes were updated.

As for wiring, the code used to allow a 20 A breaker and plug on a short run of 14 gauge wire if that was the only thing on the circuit. That was removed when they found too many circuits got extended later and the initial 14 gauge run was then insufficient, now it must be 12 gauge all the way. Measuring based on the marking on a wire cutter is not enough to be certain, you would nee to pull enough of the cable to read the casing description for the wire inside.

[M A V I C]

JoeH,

Thanks for the input. Good to hear some good input on this specific UPS.

There are two outlets on this circuit. One is about 4' to the right of the panel, and the other about 5' to the left of it. Of course, the run goes through the outlet to the right of the panel.

[Racer X]

Another thing to consider is if you are actually running a number of things on the UPS, and it is also attemting to recharge the batteries from a recent "event" then it is probably drawing a lot more power as well.

I would be astounded if your system doesn't have a main shut off breaker as well. Maybe in another smaller box between the main line into the house, and your actual distribution panel.

[Bill in NC]

Could you meet your needs with one of those 1500VA UPS that are often on sale for $99?

[M A V I C]

[quote Bill in NC]Could you meet your needs with one of those 1500VA UPS that are often on sale for $99?
I'd want one with AVR. I had been shopping for a while. The cheapest I've been able to find a 1500VA one with AVR is about $130. Do you know where to find better deals?

[Bill in NC]

belkin 1500VA units have avr