Electrical question - metal receptacle boxes not grounded?

[Dave Carney]

I just had a new service installed into my new garage by an electrician. Very basic service which I will extend later. The installation passed inspection this week. I noticed that the electrician did not ground the metal receptacle boxes (one for a gfi outlet, one for a light switch) and I don't see a grounding screw for the box anyway. Is this some of kind of self grounding rig through the device screws or is it wrong? It's romex wiring. The ground wire was run to the directly to the switch on the one box and directly to the gfi outlet green screw on the other.

I thought all metal boxes needed a grounding wire unless using conduit? No?

 

[Dave Carney]

Picture is worth a thousand words...

 

[Nimrod]

The box will ground through the receptacle...the ground screw on it is part of the metal bracket that screws to the box.

But I am not an electrician.

 

[Dave Carney]

I think you are right. Thanks!

 

[rockwithjason]

Technically the box should have a ground screw in it with the bare ground wrapped around it. In the real world the box will ground thru the recepticle if the recepticle has the bonding yoke on one or both of the mounting screws. The yoke method is acceptable in most cases.

 

[Dave Carney]

I'll need to run a ground jumper when I extend that circuit anyway. Otherwise with the receptacle removed the ground chain would be broken.

 

[DIGGER_DAVE]

The BEST bet is to check your local codes.
From what I read in the responses above; there were several different methods used.

From my old electrician days (and present code) - "a ground wire must be run from the main panel (which MUST be grounded; either to a water main pipe, OR an Approved GROUND STAKE) to each "sub panel" (of suitable gauge) and in turn attached to BOTH the receptical boxes AND the devices in the recepticals."

Relying on just the receptical screw "grounding" to the individual boxes is NOT sufficient.

BUT ... that's our code

 

[Dave Carney]

I bought a bag of ground screws today, I'm going to ground all the boxes that way, with another jumper wire. There's a threaded hole at the back of the box for a ground screw. Required or not, I'd feel better about it. Thanks everyone.

 

[rockwithjason]

good move.

 

[sberry]

Its not something to lose sleep over. The code does require devices mounted in the covers to have a jumper wire to the box but the wire to the recept or device is about as good as it gets. The main intent with the code is when the box and metal piping IS used as the grounding pathway. The main concern is when the ground is the box, they dont want an ungrounded cover at any time and some of them only mount recepts with the center screw, not very physically secure. With the wire already installed to the device and the cover securely screwed the wire would be redundant. If the device, the recept is screwed to the box itself you wouldnt need the wire, the would be grounded, the only issue with this again is with the use of metal cover plates.

 

[indyjps]

i pigtailed my ground wire and looped a drywall screw around it and screwed thru the box into a stud, the boxes were flush mounted. my elec was happy with the set up and hooked all into the main panel for me. used pvc piping to metal boxes.