15 vs. 20 amp receptacles

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  #1  
Old 07-07-07, 11:37 AM
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15 vs. 20 amp receptacles

I noticed all the receptacles that I've checked in my house are 15A, even though some are on 15A circuits and some are on 20A circuits. When is a 20A receptacle used? Same question for switches.
 
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  #2  
Old 07-07-07, 11:44 AM
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You should have told us where you live. I am assuming the US. Rules in Canada are different.

In the US you are allowed to use 15 amp receptacles on 20 amp circuits, as long as you have more than one receptacle. And yes, a duplex receptacle counts as more than one receptacle.

20 amp receptacles are only needed when you have a 20 amp device. A 20 amp device will have a 20 amp plug on it. An example would be an air conditioner.

You are allowed to use 20 amp receptacles on any 20 amp circuit, so some people use them thinking they have to, others use them thinking they might have need of one, and other use them thinking they are somehow better (some one told me they "grip better" than 15 amp ones).

The only time that a 20 amp receptacle is absolutely required on a 20 amp circuit is when there is single "simplex" receptacle installed.
 
  #3  
Old 07-07-07, 12:16 PM
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And they "grip better" because they are professional grade in almost all instances. But you can also buy professional grade 15A receptacles. People just don't usually see the value in a $6 receptacle when the $1 receptacle is the same 15A style. They just don't usually get the cheaper choice when it comes to buying the 20A style.

Good point.
 
  #4  
Old 07-07-07, 12:31 PM
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Thank you! I guess I don't have any '20A' appliances.

Is the same true for switches? Is a 15A switch o.k. for a garbage disposal, for example?

(I live in California)
 
  #5  
Old 07-07-07, 01:35 PM
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Unlike the wires, which are sized to the circuit protection (circuit breaker size), the switches can be sized for the load. Even when on a 20A circuit with #12 wires, you can use a 15A switch for most lighting loads.

Is your GD on a separate dedicated circuit? What info is on the motor's nameplate? You may wish to use a good 20A switch there. In fact, I also like the momentary switches that are available.
 
  #6  
Old 07-08-07, 10:30 PM
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The disposal is an older model called Badger 5. I couldn't find the nameplate -- it's probably in the back where I can't see it. Whoever put it in originally put it on the countertop receptacle circuit. I'll be replacing it with a new one and rewiring it to the dishwasher circuit which is currently a dedicated line. It would be an easy matter of replacing the 15A switch with a 20A switch if it's safer. What's a momentary switch?
Thnx
 
  #7  
Old 07-09-07, 09:31 AM
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The badger 5 is a 1/2 HP model, which is just fine on a 15A toggle switch. If you had a big 1 HP disposal, then a spec grade 20A switch would be a good idea.

> What's a momentary switch?

A spring-loaded switch that is only on when a person is physically holding it on. You can't turn it on and walk away for example.
 
  #8  
Old 07-09-07, 10:05 AM
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Thanks, that's helpful.

On a related note of 15 vs. 20 Amp devices, when is it o.k. to mix 12 and 14 gauge wiring? I just discovered a track light in my bedroom on a 20 amp circuit (20A breaker) which uses 12 gauge (NMB 12/2) wiring. It looks like the light was added to the circuit, however 14 gauge (NMB 14/2) wiring was used for the 6 feet or so from the power source where it was added. The fixture itself has some skinny stranded wires which attach to the 14 gauge hard wiring. Is there a certain length that wire can be and still be safe? Or do I need to replace that 14 with a 12 gauge wire?
 
  #9  
Old 07-09-07, 10:18 AM
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It violated Code. Only when part of a [UL]-Listed fixture can the wires be smaller than that required by the branch circuit, which is #12 for a 20A circuit.

Now, ask me if I think you are in any danger, assuming the wires were properly installed.

There are two ways to bring in line with the Code, if you so desire. Replace that section of cable with #12, or replace the breaker with a 15A.
 
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