ECN Forum Forums General Topics of the Trade General Discussion Area 15Amp GFCI on 20Amp Circuit?

Jay,
[quote]the 20 amp receptacle should be polarized for 20 plugs and therefore the 15 amp 16 gage extension cord couldnt be plugged into it, ... [quote]
15 amp cord caps will fit in 20 amp receptacles...20 amp caps won't fit in 15 amp receptacles. At least that is how it is in the US.
Don

Thanks Don.

Jay here are the configurations we use in the US, I don't know if they match Canada.








As you can see the 20 amp receptacle is intended to accept both 15 and 20 amp plugs.

In reality there are almost no home appliances that come with a 20 amp plug on them.



Virtually all 125 volt home appliances have 15 amp plugs.



Bob


[This message has been edited by iwire (edited 11-23-2006).]

Jay a 20 amp breaker will allow 20 amps for at least 3 hours and likely forever.

It may even allow 24 amps forever.

The standard modeled case breakers we use for branch circuits are hardly precise devices and much depends on the ambient temperature where the breaker is located.

If your interested, look at some trip curves for breakers, they can be found at the web sites of the manufacturers.

[This message has been edited by iwire (edited 11-23-2006).]

i dont want to drag this out forever, but my point was simply that 16/20/24/2000 amps it doesnt matter, if code is allowing cheapo 16 gage extension cords on the 20 amp overcurrent, I see a potential hazard - or am I out to lunch here?

Am I wrong in the opinion that the NEC and CEC are based on protecting the wires in the wall and the devices attached to those wires? Not necessarily the devices plugged into or attached to the circuit.

I am not sure about the NEC, but the CEC bases the maximum loading of circuit breakers at 80% of Maximum Capacity (or the manufacturers base loading at 80% continuous draw). Here in Canada, we are not allowed to put a NEMA 5-15R rated for 15amps on a 20amp circuit. It doesn't matter that the receptacle is rated for 20amp, it is classed as a 15amp device and is therefore required to be on a maximum 15amp circuit.

Further, we are not allowed to install the NEMA 5-20R on a 15amp circuit... the circuit and breaker must be wired to allow for the maximum ampacity of 20amp. However, there is no restriction to plugging a 15amp device into the 20amp T-slot device, as it is designed to accept both 15 and 20 amp devices.

Is this not correct?



[This message has been edited by ExpressQuote (edited 11-23-2006).]

If you have something like 240.4(D) (15a on 14ga copper, 20a on 12ga) you already have the 80% built into the overcurrent protection. The NFPA understands they have no control what a user will plug in. Even if you limited each receptacle to 15a configuration, that doesn't keep someone from plugging two 1440 watt heaters into receptacles on the same circuit. They set the overcurrent protection artifically low for "small conductors". 310.15 says a 14 copper is good for 20a and a 12 good for 25a, at 60c. There is your 80%.