GFI question.

[Allan Speers]

I want to add a few outlets to the outside of my garage / shop. One will be 15a and one will be 20a.

A have a bunch of (non-boxed) 2-pole 20a GFI's on the shelf, but they all look different, & I can't figure out what those differences mean:
## note that they all say 20a right on the GFI's themselves.

One type has the expected 20a blade slots, where the neutral is like a sideways "T." It says Leviton "M", and 125v

Another type has slots like I'd expect on a 15a unit. There's no way to insert a 20a male plug, with the sideways neutral. Huh? It says Leviton "N", and 120v

The third type is like the second, above, but also has a little green LED. Is that a self-test LED?

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So... I don't get it. ow can the sticker say 20a if a 20a plug won't fit? And why is one 125v while the other is 120v? I know that makes no prctical difference, but it's the same manufacturer, and they were purchased around the same time. (Maybe 3-4 years ago.)


Also: Is it OK to use a 20a GFI on a 15a circuit, if it only has the "15a" type of slots? (Or are those not really 20a after all?)


thanks.

[Allan Speers]

Related question:

I see Hubbel brand (type?) GFCI's online (not hospital grade) for about $10 more than what those Levitons cost. Is there really a difference? Do they last longer after tripping a few times?

[Allan Speers]

OK, I guess I found the answer. #2 & #3 are 15a outlets, but "pass through" 20a.

Why would someone want this? I find it odd that they are marked "20a" with a sticker, but no explanation.

Well, whatever.....

[Jason Roehl]

OK, I guess I found the answer. #2 & #3 are 15a outlets, but "pass through" 20a.

Why would someone want this? I find it odd that they are marked "20a" with a sticker, but no explanation.

Well, whatever.....

There's an exception in electrical code for this situation. 15A receptacles can be put on 12AWG wiring and a 20A breaker, provided there is more than one receptacle (a duplex receptacle counts as two). Thus the need for 20A pass-through.

[Wade Lippman]

There is no difference between 20 and 15a outlets, except for the slots. The 15s can go on either 15 or 20a circuits; the 20s require 20a circuits.
I have never had a HF fail, so I wouldn't be concerned about Leviton.
Some have lights; some don't. That's all.

I would be happy to know why my arc faults keep tripping!

[Allan Speers]

Great to know, guys. Thanks.


Any idea why the "15a" ones say 120v, and the 20a ones say 125v? Again, there's obviously no practical difference, but that seems very strange.

[Bruce Wrenn]

I would be happy to know why my arc faults keep tripping!

Cause they are arc fault breakers. When you unplug (or turn off) any device, they are prone to tripping. This causes an arc. A PITA for sure. The newer ones are better than the originals.

[Wade Lippman]

Cause they are arc fault breakers. When you unplug (or turn off) any device, they are prone to tripping. This causes an arc. A PITA for sure. The newer ones are better than the originals.

Nothing has been unplugged. Turning stuff off with trip them? They might just get replaced.

[Lee Schierer]

The third type is like the second, above, but also has a little green LED. Is that a self-test LED?

That LED tells you when the GFI is set and not tripped.