Why 20 amp circuits?

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mbrooke

mbrooke

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Why does the code require 20amp circuits in homes?


Reason I ask is because in Canada everything is number #14 including the SABC, bathroom and laundry circuit with no reports of tripping. Second there are no NEMA 5-20p cord caps in residential.


Just seems weird that code would dictate design.
 
Because we love to plug in lots and lots of plug strips and see how many NEMA 5-15 plugs can physically occupy the same receptacle circuit.

Weird that the Code governs design? :lol:
 
MAC702 said:
Because we love to plug in lots and lots of plug strips and see how many NEMA 5-15 plugs can physically occupy the same receptacle circuit.

Weird that the Code governs design? :lol:
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But does it ever add up to 20amps? Most get very hot nearing 13 amps.
 
mbrooke said:
Why does the code require 20amp circuits in homes?


Reason I ask is because in Canada everything is number #14 including the SABC, bathroom and laundry circuit with no reports of tripping. Second there are no NEMA 5-20p cord caps in residential.


Just seems weird that code would dictate design.
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In fairness, the CEC requires more dedicated circuits and only allows 2 outlets per 15 amp SABC. So I think in Canada the load is spread out over more 15 amp circuits.

That being said, I think we should abolish the use of 20 amp circuits in dining rooms, washers and bathrooms.
 
peter d said:
In fairness, the CEC requires more dedicated circuits and only allows 2 outlets per 15 amp SABC. So I think in Canada the load is spread out over more 15 amp circuits.
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True, there is that. But I mean still. 3va per foot is NEC code minimum, most wired to about 5-6va per foot under the NEC before AFCIs and those homes are doing fine despite violating the CEC's 12 outlets per circuit.




That being said, I think we should abolish the use of 20 amp circuits in dining rooms, washers and bathrooms.
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Yup :happyyes::happyyes:
 
peter d said:
In fairness, the CEC requires more dedicated circuits and only allows 2 outlets per 15 amp SABC. So I think in Canada the load is spread out over more 15 amp circuits.

That being said, I think we should abolish the use of 20 amp circuits in dining rooms, washers and bathrooms.
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Laundry receptacle circuit too? My washer and gas dryer each draw around 10 amps so a 20 amp circuit is needed for them to operate at the same time.
 
peter d said:
True, I was thinking of having an electric dryer. In that case, a 20 is definitely necessary or two 15's.
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But that is still design related. If I am building a new home with oil heat and a laundry closet on the second floor the 20amp behind the washer will never see more then the 10amp motor.
 
Not to mention average joe blow plug in window air conditioners, space heaters, into general branch circuits
 
What gets more interesting is the systems in Europe. I have a choice of 20 amp or 32 amp for radials... to feed my outlets.
Both are for 13 amp max fused plugs.
both require a minimum of 2.5 mm wire which is the equivalent of around 14 gauge according to many web sites. I can put unlimited outlets on each. But the difference is in how many square meters or square yards each circuit is covering.

Only requirements in double checking is insulation resistance and voltage drop tests.

Is it because of the higher voltage only? I mean, to me it means I am allowed double the wattage on the same 14 gauge wires?

Personally, though, I usually design with between 8 to 14 outlets per circuit anyway. Even on my lights. Not too sure why I get antsy any time I reach 12 outlets.
 
In a Canadian kitchen You need at least 5 dedicated circuits. (Not including a range)
1 for fridge
1 for microwave (not a countertop one, only if the cabinets have a spot for one)
1 for dishwasher
at least two for countertop/ island/ peninsula receptacles ( depends on how many you have, no more than two outlets per circuit, can be 2 single 20’s, or 2 split 15’s)

nothing else can be connected to those so another circuit is needed for lighting, hood fan and any wall receptacles



other dedicated circuits required

1 for laundry room(dryers are typically 240 volt also on a dedicated circuit)
1 for utility room
1 for a central vacuum
1 for garage ( electric vehicle separate )
1 for outside receptacles
 
mbrooke said:
Why does the code require 20amp circuits in homes?


Reason I ask is because in Canada everything is number #14 including the SABC, bathroom and laundry circuit with no reports of tripping. Second there are no NEMA 5-20p cord caps in residential.


Just seems weird that code would dictate design.
Click to expand...

I have seen breakers trip on the 20 amp small appliance circuits when people pug to many items into a 20 amp circuit.

I see nothing at all wrong with requiring a minimum of 2 ea. 20 amp small appliance circuits.

You do know that there are one heck of a lot more Canadians living in the USA than there are Americans living in Canada.
 
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