# 20A vs 15A recepticle question



## Hawkeye_Pierce (Jun 19, 2006)

I work in theater as a lighting designer and I also apprentice with a local electrician. 

So here is my question

The majority of circuits in theatrical applications are run from dimmers with 20 amp breakers.


Sometimes fixtures and cable use an Edison (NEMA 5-15 or just a household style) connector.

5-20R connectors which are rated at 20 amps have the neutral prong rotated 90 degrees compared to 5-15's.

Other than the neutral spade being rotated 90 degrees, is there any difference between a 5-15 and a 5-20R connector mechanically? Does this mean I can still run 20amps through a 5-15 connector? This would make sense to me considering that you can use 15 amp receptacles on a 20amp branch circuit.

Assume all circuits are using 12AWG wire

Just wanted a second or third opinion Thanks!



5-20R NEMA Connector:

*- |
.*


5-15 NEMA 
*
| |
.*


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## ko_jun (Jul 13, 2006)

15a receptacles only draw 15a max. you can use 15a receptacles on 20a circuits but cant use 20a receptacles on 15a circuits.

they figure if your gonna draw close to the max amperage, it would be a dedicated circuit


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## Mike Finley (Apr 28, 2004)

ko_jun said:


> 15a receptacles only draw 15a max. you can use 15a receptacles on 20a circuits but cant use 20a receptacles on 15a circuits.


Say what?


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## mdshunk (Mar 13, 2005)

ko_jun said:


> 15a receptacles only draw 15a max. you can use 15a receptacles on 20a circuits but cant use 20a receptacles on 15a circuits.
> 
> they figure if your gonna draw close to the max amperage, it would be a dedicated circuit


It's easy to see that he pulled that right out of his back side.


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## Hawkeye_Pierce (Jun 19, 2006)

Nor does it come close to answering my question. Was I not clear enough? It was late. 

Anyone out there have an answer?


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## maj (Mar 13, 2006)

Hawkeye_Pierce said:


> Nor does it come close to answering my question. Was I not clear enough? It was late.
> 
> Anyone out there have an answer?


I was wondering the same thing Hawkeye..... 

I'm also curious about this , but still waiting for someone qualified to answer your question. I think I know, but I'm not an electrician. I just want some confirmation to my answer.


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## Speedy Petey (Sep 30, 2003)

It's actually kind of useless, the whole concept of 120v 15 & 20 amp receptacles. 

More that one 15a receptacle (even one duplex) can be on a 20a circuit.
NO 20a receptacles can be on a 15 amp circuit.

Yes, the only difference is the plug configuration. BOTH can feed through 20 amps.
They main difference is that you cannot plug in ONE 20a rated appliance into a 15a receptacle, single or duplex. Yet you can plug in two 10a rated appliances. This is why the whole concept is flawed.


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## Mike Finley (Apr 28, 2004)

Speedy Petey said:


> NO 20a receptacles can be on a 15 amp circuit.


Can you elaborate on that?

Do you mean by code?

I ask because recently I saw a 20 amp GFCI outlet on a 15 amp circuit. The GFCI was not side ways slotted. I figured maybe wrongly that it was over built for the situation and wouldn't be an issue.


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## CE1 (Dec 30, 2005)

Hawkeye_Pierce said:


> I work in theater as a lighting designer and I also apprentice with a local electrician.
> 
> So here is my question
> 
> ...


For commercial applications you must install 20 amp devices on 20 amp circuits, especially movie sets and theaters. No 15 amp receptacles on 20 amp circuit breakers. 
Devices are tested by UL, CE, IEE, DIN and other nongovernmental groups for their intended use. A 20 amp receptacle is tested for drawing 20 amps and certified to do so. A 15 amp plug is is tested for 15 amps and certified to do so. Then it gets the agency's stamp of approval for this rating and intended use. The NEC is for Minimum electrical construction standards and UL, CE, IEE, DIN etc sets general engineering standards and certifies the construction and end use of devices, equipment, appliances, etc. There is a big difference as to what these agencies do. In the US always look for the UL label on equipment, because there is equipment out there that do not have it and are a potential fire hazard.

To answer your questions about 15 amp and 20 amp plugs and connectors. You can use a 15 amp plug attached to a 20 amp receptacle/connector as long as what is attached to the 15 amp plug is rated for no more than 15 amps ( UL, CE, IEE, DIN approved). A very bad example of this would to have a 75 watt lamp in a light fixture that is rated and approved for no more than a 60 watt lamp. This would be a fire hazard and a big OSHA, fire code violation. You want to watch out for this type of thing in you work environment.


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## quasike (Jul 20, 2006)

Please do not overlook the simplicity of the 20A receptacle with the sideways bar, type 20N? 
Especially in Commercial Applications.
Becasue this bar should automatically indicate there is a 20A C.B. or may assume it's a dedicated outlet. -when someone is looking for 20A, they are going to look for this type of receptacle.
For example, in office buildings where they need to plug in Copy Machines, or a contractor/workshop to plug in a 120v Shaper, etc. particularly if there isn't a confirmed dedicated outlet for these items


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## CE1 (Dec 30, 2005)

quasike said:


> Please do not overlook the simplicity of the 20A receptacle with the sideways bar, type 20N?
> Especially in Commercial Applications.
> Becasue this bar should automatically indicate there is a 20A C.B. or may assume it's a dedicated outlet. -when someone is looking for 20A, they are going to look for this type of receptacle.
> For example, in office buildings where they need to plug in Copy Machines, or a contractor/workshop to plug in a 120v Shaper, etc. particularly if there isn't a confirmed dedicated outlet for these items


????:huh: 

Let's All talk the same here:

View attachment 2518


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## maj (Mar 13, 2006)

ko_jun said:


> *15a receptacles only draw 15a max. you can use 15a receptacles on 20a circuits but cant use 20a receptacles on 15a circuits.*
> they figure if your gonna draw close to the max amperage, it would be a dedicated circuit


So why is what ko_jun said here wrong? Forgive my ignorance, as I know this is very simple, but what I read here from ko_jun makes sense to me. But I'm not sparky, just a wood butcher.


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## tribe_fan (May 19, 2006)

I'm not a real sparky, my "specialty" would be on the service/mfg of small equipment. (I tell the electrician what I need, and he installs it) The purpose of these "special" plugs is to ensure that you don't plug equipment into an underrated outlet. 

A 15 plug would fit into a 20 recpt. A 20 plug would not fit into 15 receptacle. 

(Of course I have to trust that an electrician would never put a 20a receptacle on a circuit only rated for 15a - but in a commercial environment this would be rare.)


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## CE1 (Dec 30, 2005)

You can plug a polarized two prong plug, a 15 amp grounded plug or a 20 amp grounded plug into a 20 amp receptacle. 

You can plug a polarized two prong plug or a 15 amp grounded plug into a 15 amp receptacle.
Nothing else will work.


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