Why 20 amp circuits?

[Tony S]

You would be correct, 4mm would typically be used.


#10 is 3.31mm2


FWIW the wire ampacity is determined by the "installation method". Meaning if the wire has fiberglass around it the rating drops almost by half as apposed to no insulation.



http://www.batt.co.uk/upload/files/currentratingstable4d5_1312876143.pdf


As an example 2.5mm2 which is slightly larger then #14 (2.08mm2) is rated 13.5amps in an insulated wall, but 27 amps if tacked directly to say a basement joist.

One reason for 2.5mm2 being rated less then 2.08mm2 is Twin and earth uses 70*C insulation, where our NM has 90*C wires.

4mm² for a 32A radial or 2.5mm² for 20A. Now we have AFDD’s (AFCI) inflicted upon us the ring circuit is doomed, an AFDD will not work on a parallel circuit.

 

[Knuckle Dragger]

I can't recall any issues that I or any of my customers have had with 20 amp SABC on the kitchen counters and bathrooms etc and 15 amp circuits where 20 amp isn't mandatory.
IMHO the NEC gives us the minimum requirements in and they leave to the licensed professional and their customers to take it from there.
Go Pats!

 

[Eddy_Current]

A 15A receptacle is allowed on 20A circuits, because it is rated to carry 20A among the rest of the receptacles in the same circuit. The 15A rating refers to the fact that it is only rated to deliver 15A to its own local loads.

We can not do that in Canada, 20 amp circuit must have 20 amp receptacles here.

On 20 amp circuits? OK, I got ya.
I wonder if they allow common neutrals without straps! Now that I would be interested in...

Yes we can do that with single phase and three phase. We only need to tie breakers together if they are all for the same device.

Keep in mind guys, i’m not saying our codes are better than yours, just comparing for those interested.

 

[kwired]

We can not do that in Canada, 20 amp circuit must have 20 amp receptacles here.




Yes we can do that with single phase and three phase. We only need to tie breakers together if they are all for the same device.

Keep in mind guys, i’m not saying our codes are better than yours, just comparing for those interested.

Your code is better ever since NEC required handle ties on all MWBC's

 

[ActionDave]

....We only need to tie breakers together if they are all for the same device.

Keep in mind guys, i’m not saying our codes are better than yours, just comparing for those interested.

The part in red is better than our code.

 

[Coppersmith]

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

I think about moving to Canada all the time. Too bad it's cold there.

 

[mbrooke]

4mm² for a 32A radial or 2.5mm² for 20A. Now we have AFDD’s (AFCI) inflicted upon us the ring circuit is doomed, an AFDD will not work on a parallel circuit.

Have they said why it won't work? They are still optional now, correct?


I'm sorry this fraud has taken ground in your country, even though 20 years ago UL and others were poring over BS7671 due to its arc protection capabilities. If can't make stuff like this up.

 

[mbrooke]

We can not do that in Canada, 20 amp circuit must have 20 amp receptacles here.

What is the reasoning? Also is commercial 20 or 15 amp?

 

[Eddy_Current]

What is the reasoning? Also is commercial 20 or 15 amp?

The reason is because our code says so 26-700(2)

As for commercial you can install whatever you want as long as the overcurrent matches the receptacle. Typically most receptacles are 15 amp other than dedicated ones for printers etc. Often in commercial the housekeeping receptacles (hallways) are 20 amp but there is no code, that is in the spec.

We also have a code that limits us to no more than 12 receptacles max for any circuit, residential or commercial.

 

[mbrooke]

The reason is because our code says so 26-700(2)

As you know, thats not a reason Code often has there own reasoning behind making a rule.

As for commercial you can install whatever you want as long as the overcurrent matches the receptacle. Typically most receptacles are 15 amp other than dedicated ones for printers etc. Often in commercial the housekeeping receptacles (hallways) are 20 amp but there is no code, that is in the spec.

We also have a code that limits us to no more than 12 receptacles max for any circuit, residential or commercial.

Thanks for the info

 

[Eddy_Current]

So the NEC allows you to use 15 amp receptacles on a 20 amp circuit, but is there a limit?

Like if you used a 30 amp breaker and wire, could you still use 15 amp receptacles on that circuit? If not, why is a 15 amp receptacle allowed on a 20 amp circuit? Are your 15 amp receptacles rated for 20 amps? I have one in my hand right now and it says 125 volts, 15 amps.

 

[growler]

Are your 15 amp receptacles rated for 20 amps? I have one in my hand right now and it says 125 volts, 15 amps.

The only male ended plug that will fit in that receptacle is one rated for 15 amps. So it's a 15 amp receptacle.

 

[mbrooke]

So the NEC allows you to use 15 amp receptacles on a 20 amp circuit, but is there a limit?

No limit. I can put an unlimted number of 15 amp outlets on a 20amp circuit, even feed it through the yoke itself. Everything inside is rated 20amps, even the cheap 50 cent HD ones.

Like if you used a 30 amp breaker and wire, could you still use 15 amp receptacles on that circuit? If not, why is a 15 amp receptacle allowed on a 20 amp circuit? Are your 15 amp receptacles rated for 20 amps? I have one in my hand right now and it says 125 volts, 15 amps.

[/QUOTE]


No, can't go over 20amps on a 15.

But you could place a 50amp NEMA14-50 on a 40amp circuit. Or a single (none duplex) 20 amp on a 15 amp circuit.

 

[Eddy_Current]

No limit. I can put an unlimted number of 15 amp outlets on a 20amp circuit, even feed it through the yoke itself. Everything inside is rated 20amps, even the cheap 50 cent HD ones.

No, can't go over 20amps on a 15.

But you could place a 50amp NEMA14-50 on a 40amp circuit. Or a single (none duplex) 20 amp on a 15 amp circuit.[/QUOTE]


Where do you get the info that says you can put a 15 amp receptacle on a 20? Is it a code in the NEC?

I agree that the receptacle is made the same but is it spec'd somewhere that you can put 20 amps on it?

 

[mbrooke]

Where do you get the info that says you can put a 15 amp receptacle on a 20? Is it a code in the NEC?

I agree that the receptacle is made the same but is it spec'd somewhere that you can put 20 amps on it?

This let you do it:

 

[sameguy]

I think about moving to Canada all the time. Too bad it's cold there.

For an eye opener look up what it would take to move to any 1st world country legally, you will be surprised how hard it is; not like just walking over the boarder.

 

[Frank DuVal]

Where I grew up, 15 amp receptacle circuits were combined with lighting and furnace, etc, since there were only 4 plug (Edison base) fuses in the service entrance.

My house went through a lot of 15 amp fuses. Popcorn poppers, toasters, electric fry pans, all used in dinning room or back porch, where of course it was plugged into the back porch light. Or the electric iron which took out 15 amp fuses in many homes, as ironing was done in bedroom, living room, or dining room in houses. There was no laundry , just in the basement or cramped utility room (no basement house style) was the washer. Dryer was outside!

Now about using the 1100 Watt iron* in the laundry room while the washer is running, you still sticking with that 15 amp circuit is fine?:?

So I always wire 20 amp receptacle circuits (with 15 amp receptacles) in houses. Too many times sitting in dark rooms trying to find flashlight to go replace fuses with dad.

Of course, it IS why I got interested in electricity!:thumbsup:


Rowenta makes a 1700 watt iron! What 15 amp circuit is going to hold that on while anything else is plugged in?

 

[kwired]

Where I grew up, 15 amp receptacle circuits were combined with lighting and furnace, etc, since there were only 4 plug (Edison base) fuses in the service entrance.

My house went through a lot of 15 amp fuses. Popcorn poppers, toasters, electric fry pans, all used in dinning room or back porch, where of course it was plugged into the back porch light. Or the electric iron which took out 15 amp fuses in many homes, as ironing was done in bedroom, living room, or dining room in houses. There was no laundry , just in the basement or cramped utility room (no basement house style) was the washer. Dryer was outside!

Now about using the 1100 Watt iron* in the laundry room while the washer is running, you still sticking with that 15 amp circuit is fine?:?

So I always wire 20 amp receptacle circuits (with 15 amp receptacles) in houses. Too many times sitting in dark rooms trying to find flashlight to go replace fuses with dad.

Of course, it IS why I got interested in electricity!:thumbsup:


Rowenta makes a 1700 watt iron! What 15 amp circuit is going to hold that on while anything else is plugged in?

Certainly that iron is thermostatically controlled and will cycle on/off, which may allow it to run for a long time or even indefinitely without ever tripping a 15 amp fuse/breaker. Additional load on same circuit will have an impact - but it depends on details of that load.

 

[peter d]

Where I grew up, 15 amp receptacle circuits were combined with lighting and furnace, etc, since there were only 4 plug (Edison base) fuses in the service entrance.

My house went through a lot of 15 amp fuses. Popcorn poppers, toasters, electric fry pans, all used in dinning room or back porch, where of course it was plugged into the back porch light. Or the electric iron which took out 15 amp fuses in many homes, as ironing was done in bedroom, living room, or dining room in houses. There was no laundry , just in the basement or cramped utility room (no basement house style) was the washer. Dryer was outside!

Now about using the 1100 Watt iron* in the laundry room while the washer is running, you still sticking with that 15 amp circuit is fine?:?

So I always wire 20 amp receptacle circuits (with 15 amp receptacles) in houses. Too many times sitting in dark rooms trying to find flashlight to go replace fuses with dad.

Of course, it IS why I got interested in electricity!:thumbsup:


Rowenta makes a 1700 watt iron! What 15 amp circuit is going to hold that on while anything else is plugged in?

If a house is wired to NEC minimums, there is absolutely zero reason to use 20 amp circuits for receptacles for areas where it's not required.

 

[mbrooke]

Where I grew up, 15 amp receptacle circuits were combined with lighting and furnace, etc, since there were only 4 plug (Edison base) fuses in the service entrance.

My house went through a lot of 15 amp fuses. Popcorn poppers, toasters, electric fry pans, all used in dinning room or back porch, where of course it was plugged into the back porch light. Or the electric iron which took out 15 amp fuses in many homes, as ironing was done in bedroom, living room, or dining room in houses. There was no laundry , just in the basement or cramped utility room (no basement house style) was the washer. Dryer was outside!

Now about using the 1100 Watt iron* in the laundry room while the washer is running, you still sticking with that 15 amp circuit is fine?:?

So I always wire 20 amp receptacle circuits (with 15 amp receptacles) in houses. Too many times sitting in dark rooms trying to find flashlight to go replace fuses with dad.

Of course, it IS why I got interested in electricity!:thumbsup:


Rowenta makes a 1700 watt iron! What 15 amp circuit is going to hold that on while anything else is plugged in?

Lack of dedicated circuits for the big stuff and not wiring to 3va per foot.

A laundry room is different from a washer and dryer in a closet where the receptacle can not be accessed.