Too many receptacles on a circuit?

steve66

steve66

Senior Member
Location
Illinois
Occupation
Engineer
Doing a code review for a chain business, and looking for second opinions if this is a violation or not:

A 20A single pole breaker supplies a small, plug in UPS. The UPS supplies a small panelboard, which has 20A breakers that each supply a single cash register receptacle. I count at least 20 of these receptacles.

Is that a violation of 220.14(I)? Because there are too many receptacles on a single 20A breaker?

Or does that not apply because these are not "general-use" receptacles?

Or does it not apply because the 20A breaker does not directly supply every receptacle on a single branch circuit?
 
Is sounds like there is a single 20 amp receptacle on each branch circuit. If they're 20 amp receptacles then I don't see any issues. The portion ahead of the panelboard is a feeder and is therefore not relevant.
 
ron said:
A single receptacle gets counted as 90VA, so you should be fine.
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Doesn't a "Single" receptacle get calculated at 180VA, and, 180va for multiple receptacles (up to a triple) on a single yoke?

Doesn't the 90VA per receptacle only come into play when there is a single piece of equipment consisting of 4 or more receptacles per 220.14(I) ?

Jap>
 
ron said:
A single receptacle gets counted as 90VA, so you should be fine.
Click to expand...
I should have phrased that a little more clearly. There were at least 20 duplexes.

At any rate, I've decided not to comment on this. I don't think they are considered general use receptacles (a cash register would be a very small load, and even the monitors they plug in are probably under 100 VA. ) Also, like Infinity said, the 20A circuit is actually a feeder.

Also, and I know this doesn't really have any bearing on code requirements, but I'm sure they probably install these all over the country. As picky as these places are with their POS systems, I'm sure if it every caused an issue, they would be changing the detail.
 
steve66 said:
Doing a code review for a chain business, and looking for second opinions if this is a violation or not:

A 20A single pole breaker supplies a small, plug in UPS. The UPS supplies a small panelboard,
Click to expand...
By definition I'd call that segment a feeder. I have had issues with inspectors over 400.12(1) with installations like this.
the code section would be 215.2(A)
steve66 said:
which has 20A breakers that each supply a single cash register receptacle. I count at least 20 of these receptacles.
Click to expand...
jap said:
Doesn't a "Single" receptacle get calculated at 180VA
Click to expand...
Yes
 
Code issues aside which I agree with, the problem I have is that a small, plug in UPS supplies a small panelboard that supplies at least twenty 20A duplex receptacles. While the thinking may have been that if that setup becomes problematic because of the UPS, it could always be removed and the panel fed directly with a new feeder from the main panel, I'm just not comfortable with it the way it is. You don't state how big the "small" UPS is, but I'm sure plugging something substantial into one of those unmarked 20A receptacles, like a heater, would cause the UPS to shut down. That would cause every POS terminal in the store to shut down.

I'm sure a single UPS was chosen by some IT or bean counter guy, but the correct option would be small UPSs at each POS location.

-Hal
 
If there are 20 ordinary 120V duplex receptacles that must be counted at 180VA each then that's 3600va which is 30A on the feeder, so a 20A feeder and UPS isn't enough?

What kind of UPS?
 
I don't think I've ever seen a plug-in UPS, especially a 20A one, feed a panelboard. I would say the issue is the panelboard is overloaded, not the circuit breaker.
 
Seems to me the load is known. Cash registers that probably don't even come close to 180 VA each.

similar but on other end of the spectrum:

If you are doing load calculation for a receptacle feeding a known fixed load of 1200 VA do you use 180 or 1200 in that case?
 
kwired said:
Seems to me the load is known. Cash registers that probably don't even come close to 180 VA each.

similar but on other end of the spectrum:

If you are doing load calculation for a receptacle feeding a known fixed load of 1200 VA do you use 180 or 1200 in that case?
Click to expand...
Plan reviewers usually wont catch it since they wont put it on the plans,
They would call out the feeder load calculation.
Its a judgement call, as you might have 7 180VA receptacles that pull 0VA and the last one pulls 1200VA.
As an electrician just wiring one store, I think you have lots of wiggle room, if your an engineer making a cookie cutter plan that will be used in 200 new store builds and they all start to have issues with overload, then they could go after your 'errors and omissions' insurance.
 
kwired said:
Seems to me the load is known. Cash registers that probably don't even come close to 180 VA each.

similar but on other end of the spectrum:

If you are doing load calculation for a receptacle feeding a known fixed load of 1200 VA do you use 180 or 1200 in that case?
Click to expand...
I was thinking the same thing.
Although it still seems to be a little over on wattage for a 20a circuit if it's actually 20 outlets at 100watts ea. I would think.

Jap>
 
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