Old vs New Construction using 15 vs 20 amps circuits

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Old 05-03-15, 01:06 PM
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Old vs New Construction using 15 vs 20 amps circuits

My home was built in the early '30's and is wired with 12/2 BX to 20 amp breakers.
All of my add-on work is done in 12/2 Romex to 20 amp breakers.
Are NEW homes wired primarily with 15 ---instead of 20 amps circuits?
I know 14/2 is cheaper and easier to work with and is commonly used for lighting circuits -especially with the lower wattage LED lamps.
Is there still a place for 20 amp circuits in the home -aside from the obvious dedicated washer/dryer and microwave runs?
Would love to know what electrical contractors do these days.
Thanks!
 
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Old 05-03-15, 01:18 PM
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The code specifies 20 amp circuits for kitchen receptacles, bathroom receptacles and laundry receptacles. Others are optional and are based on expected loads.
 
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Old 05-03-15, 05:20 PM
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My personal opinion (worth a cheap cup of coffee if you include your own dollar bills) is that ALL receptacle circuits should be wired with #12 and protected by a 20 ampere circuit breaker. My reasoning is that you may then plug almost anything into a receptacle without overloading the circuit.

For a developer building hundreds of homes the increased cost of #12 wire over #14 is significant, for the homeowner it is peanuts. The increased work for a professional electrician to work with the heavier and stiffer cable is definitely a drawback but for the DIYer it is minimal.
 
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Old 05-03-15, 08:05 PM
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I'm with Furd on this one.
Been to way to many fires where people have plugged in over sized A/C units, space heaters, ref. ECT. in 15 amp. circuts.
 
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Old 05-03-15, 08:53 PM
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I am with Furd on this, too. As an Electrician and in my own home, I only install 20A receptacle circuits, using all 20A rated "SPEC GRADE" devices. It's a little more expensive, but well worth it in my own opinion.
 
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Old 05-03-15, 09:23 PM
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There is no need for a 20 amp T slot receptacle in a residential setting.
 
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Old 05-04-15, 07:09 AM
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There are a handful of state and city electrical codes which have effectively eliminated 15A general-purpose circuits, however national code still allows 15A circuits in all areas other than pcboss' list.
 
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Old 05-25-15, 07:24 AM
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There is no need for a 20 amp T slot receptacle in a residential setting


...just asking...

Do all 20A receptacles have the T-SLOT? I have a LEVITON GFCI receptacle that is stamped 20A but does not have the slot.

My personal opinion (worth a cheap cup of coffee if you include your own dollar bills) is that ALL receptacle circuits should be wired with #12 and protected by a 20 ampere circuit breaker. My reasoning is that you may then plug almost anything into a receptacle without overloading the circuit.

For a developer building hundreds of homes the increased cost of #12 wire over #14 is significant, for the homeowner it is peanuts. The increased work for a professional electrician to work with the heavier and stiffer cable is definitely a drawback but for the DIYer it is minimal.


Makes perfect sense to me!
 
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Old 05-25-15, 07:38 AM
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There are a handful of state and city electrical codes which have effectively eliminated 15A general-purpose circuits, however national code still allows 15A circuits in all areas other than pcboss' list.
What is the thinking of having dedicated lamp circuits (residential) isolated from general load circuits, thereby hopefully eliminating lamp dimming when a vacuum cleaner is turned on for instance?

With today's CFL and LED lamps, would 15A circuit(s) be OK if the load(s) is correctly spread between them?

If using 20A general load circuits, would 15A receptacle use be OK if one allowed 20A receptacle(s) on a dedicated or anticipated heavy usage 20A circuit(s)?

Learning In W(BY GOD)V...
 
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Old 05-25-15, 07:39 AM
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The 15 amp devices are still rated for 20 amp feedthrough.

A 15 amp receptacle is allowed on a 20 amp circuit as long as there is more than one place to plug into. A standard duplex counts as two.
 
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Old 05-25-15, 08:52 AM
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A CFL or LED light bulb uses a fraction of the power of an incandescent or halogen yet many screw into the same E27 sockets.

I would want to make sure that if the maid/house sitter/teenager/next owner/etc screwed in a bunch of 70w halogens into sockets that used to have 16w Leds that there wouldn't be a house fire.
 
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Old 05-25-15, 11:22 AM
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I would want to make sure that if the maid/house sitter/teenager/next owner/etc screwed in a bunch of 70w halogens into sockets that used to have 16w Leds that there wouldn't be a house fire.
So you would not trust a circuit breaker to provide overcurrent protection to prevent a fire?
 
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Old 05-25-15, 11:44 AM
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There is nothing inherently wrong with having lighting and receptacles on the same circuit and to my knowledge there are no code issues doing so EXCEPT as has already been pointed out with certain code-defined dedicated circuits.

I personally prefer to have at least one receptacle circuit not be on the fixed lighting circuit in a single room, i.e. not have all the lighting and all the receptacles in a single room be on the same circuit. My reason for this is that it allows for lighting in the room if you have to work on a receptacle, keeps the lights on if you overload a receptacle circuit and gives you a near by place to plug in a portable light or power tools if you have to work on the lighting circuit. There is nothing wrong in having one room's receptacle circuit also serve the fixed lighting in another room.
 
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Old 05-25-15, 11:49 PM
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Exclamation Correction

I have a LEVITON GFCI receptacle that is stamped 20A but does not have the slot.
CORRECTION-

I went to find the unused GFCI and while the UL sticker calls for 20A, the raised plastic script denotes a 15A rating.

Guess I answered my own question...
 
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Old 05-26-15, 02:02 AM
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Most likely a reference to the slot configuration.
 
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