Power

[Pete Brown]

While the receptacle I showed supports 30A plugs it's not clear to me why you couldn't put regular 15A receptacles on a 30A circuit. The circuit breaker provides protection for the wiring not the device plugged into it.
Greg

Among other things, wire size. Most 15A or even 20A duplex receptacles are not sized to handle the larger incoming and outgoing wires. The wiring box can also get pretty tight. This is more of an issue if you use GFCI outlets, which may be why no GFCI outlets were in use in there.

More importantly, if that wire has 30A going through it due to being at or near capacity, all the upstream outlets (between you and the breaker box, as they are chained) must be able to survive 30A of current. A 15A outlet is rated to only handle 15A. Outlet go boom.

Pete

[Pete Brown]

Found this:

NEC Table 210.21(B)(3)
Circuit rating (amperes) Receptacle rating (amperes)
15 not over 15
20 15 or 20
30 30
40 40 or 50
50 50

[paul aubin]

On the 30 amp 120 circuits unless you are the original owner of the house check the wire size feeding the garage. Do not rely on the breaker size, it is possible that a previous owner installed a larger breaker due to nuisance tripping or other needs but the wire in the wall is not #10 or better.

As for GFCI requirement All general purpose outlets in unfinished basement and garages are required to be GFCI. Dedicated outlets such as those for a freezer, Dust collector, Sump pump do not have that requirement. You can buy double pole GFCI breakers $$$$$ but they are not required for dedicated uses.

/paul

[Pete Brown]

As for GFCI requirement All general purpose outlets in unfinished basement and garages are required to be GFCI. Dedicated outlets such as those for a freezer, Dust collector, Sump pump do not have that requirement. You can buy double pole GFCI breakers $$$$$ but they are not required for dedicated uses.
/paul

Also keep in mind that being GFCI protected does not mean you need a GFCI outlet in each box. You only need one on each circuit.

Pete

[Greg Funk]

More importantly, if that wire has 30A going through it due to being at or near capacity, all the upstream outlets (between you and the breaker box, as they are chained) must be able to survive 30A of current. A 15A outlet is rated to only handle 15A. Outlet go boom.
Pete

I don't really understand what you are saying here. Why would the load be running through an upstream outlet? I suppose if you were using the receptacle to tie the wires together rather than a using a mar connector? I am not an electrician so I don't know if that is proper. In any case I wouldn't do this and I am not recommending it for anyone else.

I think this discusssion is somewhat interesting but not really germane to the topic so I will bow out now...

Greg

[Brian Tuftee]

As for GFCI requirement All general purpose outlets in unfinished basement and garages are required to be GFCI. Dedicated outlets such as those for a freezer, Dust collector, Sump pump do not have that requirement. You can buy double pole GFCI breakers $$$$$ but they are not required for dedicated uses.

/paul

Only if they're 120V, 15A or 20A receptacles. Local codes may be more strict, but the NEC doesn't require GFCI protection on 240V general-use receptacles. Or on 120V receptacles at 30A or above.


Greg:
I don't think you can plug normal 15A plugs into that 30A receptacle you have pictured. This website has a good description of the various NEMA plug and receptacle configurations, and I don't see anything in 120V, 30A that mates with 'standard' 15A (or 20A) plugs.
http://www.stayonline.com/reference-...ght-blade.aspx

[Pete Brown]

I don't really understand what you are saying here. Why would the load be running through an upstream outlet? I suppose if you were using the receptacle to tie the wires together rather than a using a mar connector? I am not an electrician so I don't know if that is proper. In any case I wouldn't do this and I am not recommending it for anyone else.

I think this discusssion is somewhat interesting but not really germane to the topic so I will bow out now...

Greg

Line and Load. Load goes to other outlets. Line goes back up the chain to the source. This is most important when working with GFCI outlets.

I have no idea what a "mar connector" is.

Pete

[Greg Funk]

Only if they're 120V, 15A or 20A receptacles. Local codes may be more strict, but the NEC doesn't require GFCI protection on 240V general-use receptacles. Or on 120V receptacles at 30A or above.


Greg:
I don't think you can plug normal 15A plugs into that 30A receptacle you have pictured. This website has a good description of the various NEMA plug and receptacle configurations, and I don't see anything in 120V, 30A that mates with 'standard' 15A (or 20A) plugs.
http://www.stayonline.com/reference-...ght-blade.aspx

Well I don't have one in front of me but I was pretty sure you could plug a 15A plug into a 15A or a 20A receptacle and it looks like it would fit in a 30A receptacle as well.

[Greg Funk]

I have no idea what a "mar connector" is.

Pete

An incorrectly spelled trade name. In Canada it is common to use "Marr" or "Marrette" connectors for twisting wires together. Not sure what they use in the US.

[Pete Brown]

An incorrectly spelled trade name. In Canada it is common to use "Marr" or "Marrette" connectors for twisting wires together. Not sure what they use in the US.

Ahh. We call them "wire nuts" down here

Those show up in the boxes, for sure. Most outlets are wired through, though.

Pete

[Brian Tuftee]

Well I don't have one in front of me but I was pretty sure you could plug a 15A plug into a 15A or a 20A receptacle and it looks like it would fit in a 30A receptacle as well.

Yep, 15A plugs will fit in a 15A or 20A, 120V receptacle. However, if you look at the holes on the 30A, 120V receptacle closely, you'll see they're not compatible with the 20A or 15A plugs.

[Bill Brady]

Everyone needs to remember that the Electrical Codes are in place to protect the public from itself. If there is code rule covering an installation there is a history to go along with the rule. If you want to do your own wiring use a book that follows the latest code. The articles in non electrical trade publications are not always by the code, so be careful of these. And remember if you are not sure what to do call an electrician to do the work for you.