120v outlet on a 30a breaker?

[jute]

I thought 120v outlets were always on a 20a breaker?? I've only seen 120v/ rated for 15a and 20a... I was asked to put a 120v outlet on a 30a breaker???

 

[charlie tuna]

they also make a single pole 40 amp breaker and single pole 50 amp -- and i've never installed one but i believe they make a single pole 60 amp breaker.......................... single pole means 120 volts at the rated voltage.

 

[jute]

Thanks, I think I need to rephrase... I was asked to put a 120v duplex receptacle on a 30a breaker. I thought 120v outlets had to be connected to a 20a breaker and you needed to add another breaker/circuit for more amps not more amps to the breaker???

 

[PT]

Is it a single receptacle on the branch circuit? If so, a 30A receptacle should be installed as per NEC
SEction 210.21 (B) Receptacles.
(1) Single Receptacle on an Individual Branch Circuit. A single receptacle installed on an individual branch circuit shall have an ampere rating not less than that of the branch circuit.
Exception No. 1: A receptacle installed in accordance with 430.81(C).
Exception No. 2: A receptacle installed exclusively for the use of a cord-and-plug-connected arc welder shall be permitted to have an ampere rating not less than the minimum branch-circuit conductor ampacity determined by 630.11(A) for arc welders.
Exception 1 applies if the receptacle is dedicated for a portable motor.

There are special receptacles rated 30A, 40A, 50A. But come with special plugs because different configurations.

 

[tincan44]

You don't say what the recpt is used for? There are a few 30 A 125 V recpts out there for use with 10 AWG. The 5-30R and L5-30R recpt are two. Ofcourse it won't work very well if their intent is to 'fix' a 15 or 20 A circuit that is over loaded.

 

[hardworkingstiff]

I think table 210.21(B)(3) answers your question.

I read it as a 30-amp receptacle circuit will have to have 30-amp rated receptacles.

 

[PT]

If what is required is a 20A duplex receptacle, Its best to replace the 30A breaker with a 20A so that your receptacle and wires are protected properly. Of course if it will be serving a motor load, it will be a different story.

 

[jute]

This circuit would be ran aprox 50' and drop down in the middle of a warehouse to supply a small (Les Nesman Style) office ... It would supply power for (2) computers, (2) printers, a fax, a radio and an extra outlet for an air compressor or ??? There isn't a circuit there yet, I was asked to put these outlets on a 30a breaker, instead of running an extra 20a circuit

 

[royal]

What it sounds like too me is that somebody wants a regular duplex receptacle fed by a 30 amp circuit.
This would require a 30 amp receptacle which would make plugging in there electronics a little hard.
You might be able to get a compressor with a proper 30 amp NEMA plug ( or install one), but you don't want to do that for the electronics.
I would think it would be better to run two circuits, a dedicated 120/20 circuit for the electronics and a 120/30 for the air compressor.

Tim

 

[james wuebker]

If your power is coming from a 3 phase 120/208 panel you could get 3 single circuits from 5 wires. 3 hots, 1 netutral and a ground wire. If your getting your power from a single phase panel your could get 2 circuits from 4 wires. 2 hots, 1 neutral and a ground. You could take away the ground wires and some people will use the conduit as grounding for the circuits. If you run #12 you should be able to put them on 20 amp circuits.
Not sure if this will help you at all.
Jim

 

[celtic]

There isn't a circuit there yet, I was asked to put these outlets on a 30a breaker, instead of running an extra 20a circuit

See:
Table 210.21(B)(2) Maximum Cord-and-Plug-Connected Load to Receptacle
Table 210.21(B)(3) Receptacle Ratings for Various Size Circuits
Table 210.24 Summary of Branch-Circuit Requirements

As long as you were only "asked" you can always "refuse" 8)

 

[charlie tuna]

all the equipment you listed to be served in this office are designed to be connected to 20 circuits--max.. sounds to me the best suggested installation is to provide this office with two 20 amp circuits--one for the printer and the other for the rest of the stuff......

 

[PT]

you could have the wires of the 30A to be a subfeeder and provide a two 20A or 15A branch breakers inside the office to serve the said load.

 

[charlie b]

Re: 120v outlet on a 30a breaker?

I was asked to put a 120v outlet on a 30a breaker???

Simple answer, which agrees with the ones given above, is that you can't do it. You are right.