gfci

[jimbo78]

i want to install one for my tank, what size is best i saw 15a/125v and 20a/125v

 

[mustang51js]

doesnt really matter, it depends on the size of your wire in the wall usually there is nothing that you would be using that would use the 20 amp one ,im talking about the sidways slot.

 

[billdogg]

+1^^^ there is no benefit from using a 20A GFCI if you are putting it on a 15A breaker - check the circuit breaker at the box and go from there. It is, however, dangerous to use a 15A when it is a 20A circuit.

 

[jefnalyssa]

The 15 amp works with 14 gauge wire. The 20 amp works with 12 gauge wire.

 

[dma]

billdog, Why is it dangerous to use a 20a. GFCI rec. on a 15a. circuit?

 

[kgross]

Size the GFCI to the circuit.

I want to add something. IF possible add 2 or more of them to your system. a single gfci can mean that if anything fails your whole tank is turned off and dies. If you put in 2 of them, if only one item fails you only loose 1/2 the power, and if you have water movement devices on both circuits there is a pretty good chance you will not loose everything in the tank.


Kim

 

[dma]

billdog, I meant to ask why a 15a. GFCI breaker would present a danger on a 20a. circuit. Sorry...

 

[kgross]

The reason you don't want to use a 15 amp socket on a 20 amp circuit is that if something causes it to draw the 20 amps, the socket can fail, rather then the circuit tripping.

Kim

 

[dma]

kgross, Good point. Why put all your eggs in one basket? Plug-in GFCI adapters are available as an alternative to the more common direct-wire GFCI receptacles. The use of such adapters would permit more than one GFCI protected circuit from a single outlet. Although their physical size would preclude their simultaneous use in a single duplex receptacle, their combination could be employed in a mullti-outlet strip or adapter. Subsequent outlet strips could then be plugged into these in order to provide two or more independent GFCI ciruits.

 

[BeanAnimal]

<a href=showthread.php?s=&postid=14381005#post14381005 target=_blank>Originally posted</a> by billdogg
+1^^^ there is no benefit from using a 20A GFCI if you are putting it on a 15A breaker - check the circuit breaker at the box and go from there. It is, however, dangerous to use a 15A when it is a 20A circuit.

<a href=showthread.php?s=&postid=14383140#post14383140 target=_blank>Originally posted</a> by kgross
The reason you don't want to use a 15 amp socket on a 20 amp circuit is that if something causes it to draw the 20 amps, the socket can fail, rather then the circuit tripping.

Kim

Sorry guys... (Kim, your not wrong often) but this is not true. It is perfectly acceptable and common practice to utilize 15A receptacles on a 20A branch circuit. The NEC clearly allows this, as outlined in NEC 210.21(B)(3) and illustrated in table 2.1 of that section.

Why? All 15A receptacles MUST be UL listed for 20A service.

For the sake of completeness, you CANNOT place a 20A receptacle on a 15A branch circuit!

 

[kgross]

That really seems strange to me. I wonder if the 15a receptacles are actually certified for 20a flow? I would be worried about the receptacles not being able to handle the flow safely....

Kim

 

[kgross]

That really seems strange to me. I wonder if the 15a receptacles are actually certified for 20a flow? I would be worried about the receptacles not being able to handle the flow safely..


But then again, that is one of the reasons I hate AC regs, many of them are pretty dumb, and against everything you would do in DC work.

Kim

 

[mustang51js]

all things electrical are rated more than what they say just in case there is an overload. you dont want to put a 20 amp gfi on a 15 amp line because it may trip the breaker, there isnt alot of things that we use everyday that has a 20 amp plug on it (one horizontal prong and one vertical),usually you see this on an air conditioner or somethong loke that

 

[BeanAnimal]

Kim,

The NEC allows the 15A receptacles on 20A circuits because all 15A receptacles must be UL listed at 20A. The only difference between a 15A and 20A receptacle is the blade slot configuration.

In the converse, they do not allow 20A receptacles on 15A branch circuits. The circuit would be "safe" because a 20A device would simply trip the breaker. It is disalowed it because it would be "confusing" to an end user.

 

[jimbo78]

thanks, 15 it is

 

[kgross]

Thanks Bean,

Putting a 20 amp on a 15 amp circuit makes sense to me, I did not know that the 15 amp receptacles were tested to 20 amp,

Kim

 

[BeanAnimal]

No problem Kim. It is a very common question and the logic, at first, appears to be opposite of what it should be.

If you have a chance, look at the section of code I outlined. If you put it in google, you will also find "supporting opinion" from the NFPA as to why they have worded the code as it is.

So that we are clear (for others reading along_

In the United States, according to the NEC:
You can use 15A and 20A receptacles on 20A branch circuits
You can ONLY use 15A receptacles on 15A branch circuits

In Canada:
As far as I know, you can ONLY use 15A receptacles on 15A branch circuits and ONLY use 20A receptacles on 20A branch circuits.

I do not have a CEA code referecen for Canada, but did post the NEC reference above.

If in doubt, consult a professional

 

[dma]

The only thing that might be added to BA's well-grounded (haw,haw) tech info is that in the case of a 20a. circuit terminating into a SINGLE outlet the NEC specifies that a 20a. device must be installed. Hardly relevent, but I couldn't resist.
Nice work BA, there is so much confusion and erroneous assumption out there concerning practical electrical theory and code; it is a refreshing to come across an informed voice in such a forum.

 

[BeanAnimal]

Thanks DMA

In full disclosure... I am not an electrician, I just eat them (the weak ones) for lunch

 

[Lifes A Beach]

Just for clarification...if the circuit breaker is listed as 20 amp, should the gfci receptacle also be 20 amp?