15A Duplex on 20A circuits

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kb3zvn

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I recently saw a house without a single 20A duplex receptacle. I know you can use a 15A duplex receptacle on a 20A line, but not vice versa. Is it really legal to use a 15A GFI on the small appliance circuits, laundry circuits, and bathrooms where a 20A circuit is required? If this is legal it would save some money.

Thanks in advance!!
 
kb3zvn said:
I recently saw a house without a single 20A duplex receptacle. I know you can use a 15A duplex receptacle on a 20A line, but not vice versa. Is it really legal to use a 15A GFI on the small appliance circuits, laundry circuits, and bathrooms where a 20A circuit is required? If this is legal it would save some money.

Thanks in advance!!
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15's are fine on the bath, sabcs, laundry 20 a ckts as long as there is more than one receptacle on the circuit- a duplex counts as two receptacles.
On top of it not being required, there is no benefit to using 20a devices- how much stuff have you seen in a house that has a 20a cord cap?:)
 
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kb3zvn said:
I recently saw a house without a single 20A duplex receptacle. I know you can use a 15A duplex receptacle on a 20A line, but not vice versa. Is it really legal to use a 15A GFI on the small appliance circuits, laundry circuits, and bathrooms where a 20A circuit is required? If this is legal it would save some money.

Thanks in advance!!
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user 100 already answer your question but I would just like to add a comment.


You proably won't see any 20 amp receptacles in any of the newer houses ( I know I don't ) but at one time some electricians and maybe inspectors did "think" they needed 20 amp receptacles on required 20 amp circuits and that's why you will see them in the older houses.

Once a myth starts it's slow to die so there may be electricians that still use 20 amp receptacles for small appliance circuits. Doesn't hurt anything just makeing Home Depot more money.
 
growler said:
user 100 already answer your question but I would just like to add a comment.


You proably won't see any 20 amp receptacles in any of the newer houses ( I know I don't ) but at one time some electricians and maybe inspectors did "think" they needed 20 amp receptacles on required 20 amp circuits and that's why you will see them in the older houses.

Once a myth starts it's slow to die so there may be electricians that still use 20 amp receptacles for small appliance circuits. Doesn't hurt anything just makeing Home Depot more money.
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I do see tons of 20A receptacles in commercial buildings... have to believe they are there by build specs. The only advantage Ive seen to 20A receptacles are the screws come out further making getting 12 ga wire terminated a bit easier.
 
Several years ago I wired a radio communications bldg. for a local municipality. All the Motorola equipment, controllers and repeaters came with 20amp plugs. Only time I remember seeing any.
 
Why can't you use a 20A receptacle on a 15A circuit if the circuit is protected by a 15A breaker? I mean, sure...it would be tempting or give the wrong impression to somebody who actually had equipment with a 20A cord cap, but they would quickly find out it wouldn't work.

It's not dangerous or anything. I mean, unless the breaker fails to trip. But that could happen with any breaker.
 
jaylectricity said:
Why can't you use a 20A receptacle on a 15A circuit if the circuit is protected by a 15A breaker? I mean, sure...it would be tempting or give the wrong impression to somebody who actually had equipment with a 20A cord cap, but they would quickly find out it wouldn't work.

It's not dangerous or anything. I mean, unless the breaker fails to trip. But that could happen with any breaker.
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Potential overload of the circuit?
 
20 amp duplex receptacles seem more durable than 15 amp.
I would typically install 20 amp duplex receptacles wherever there maybe higher continues loads or wherever they maybe used and abused ie. having the cord repeatedly plugged in and out.
 
Knuckle Dragger said:
20 amp duplex receptacles seem more durable than 15 amp.
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Not so much.

If you take apart a 15 and 20 amp duplex of the same grade from the same manufacturer you will usually find the internal parts are exactly the same. The only difference is the plastic cover over the front

You can get better 15 amp receptacles by just asking for a better grade.
 
jaylectricity said:
Why can't you use a 20A receptacle on a 15A circuit if the circuit is protected by a 15A breaker? I mean, sure...it would be tempting or give the wrong impression to somebody who actually had equipment with a 20A cord cap, but they would quickly find out it wouldn't work.

It's not dangerous or anything. I mean, unless the breaker fails to trip. But that could happen with any breaker.
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Sierrasparky said:
Potential overload of the circuit?
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Its likely that most equipment with a 5-20 cord cap doesn't pull a full 20 a- probably 12-18 load as a max and and that upper end may not trip a lot of 15 a breakers, but is there still a hazard beyond that due to the wiring being #14? No- 14 can safely handle a little more than 15 amps continuosly.

But the system works as is, so no need to change it.:)
 
iwire said:
Not so much.

If you take apart a 15 and 20 amp duplex of the same grade from the same manufacturer you will usually find the internal parts are exactly the same. The only difference is the plastic cover over the front

You can get better 15 amp receptacles by just asking for a better grade.
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From what I see on the outside of the 20 amp duplex receptacles I use (Leviton and P& S) the 20 seems more durable 15 amp. That being said I have never had a comparison stress test in an independent lab.:)
 
Knuckle Dragger said:
From what I see on the outside of the 20 amp duplex receptacles I use (Leviton and P& S) the 20 seems more durable 15 amp. That being said I have never had a comparison stress test in an independent lab.:)
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If you compare a cheepo 15A recpt to a spec grade 20A, then yes, the 20A is better, but if you have the same grade the only difference between them is the extra notch in the plastic.
 
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