Wiring new range

odo53May 8, 2012

I want to update the range outlet from an older style 3 prong (10-50R) surface mount box to an inwall 4 prong (14-50R) for my new range. The new range is tighter to the wall so the inwall connection makes better use of space. The existing cable is non-metal sheathed 3 conductor 8 awg with a 10 awg ground. I have put in a double gang metal box for the outlet and run the cable into it with proper clamping.

What is the required grounding procedure for the metal gang box? I have 14 awg grounding pigtails and I have the special green #10 screws for 20 amp, 120V service but this seems inadequate compared to the 8 awg wires that are carrying current in. What is the required wire gauge for grounding the box? How do I attach that cable to the box? Can I use the pre-threaded hole with a #10 screw?

Thanks much!

Thank you for reporting this comment. Undo

Ask on the Electrical Forum.

    Bookmark   May 8, 2012 at 6:05PM
Thank you for reporting this comment. Undo

You cannot adapt an existing 3 wire circuit. You are required to run an entirely new circuit from the box with 4 wires.

    Bookmark   May 9, 2012 at 12:07AM
Thank you for reporting this comment. Undo

Thanks live_wire_oak. Agree that you can't simply convert a 3 wire installation to a 4 wire, but the existing cable I have has 4 wires, 3 x 8 awg plus a 10 awg ground. The old install didn't use the separate dedicated equipment ground but it is grounded at the main breaker panel. Seems OK to me. Am I overlooking something?

    Bookmark   May 9, 2012 at 9:16PM
Thank you for reporting this comment. Undo

The 10 AWG ground wire should be connected to 10 AWG grounding conductors from the box and from the receptacle. This is within the capacity of "blue" wire nuts, or a U bolt clamp. You can of course go larger.

The cable is attached to the box using an appropriate connector. The connector looks like a 12/2WG NM (Romex) connector on steroids.

The no. 10 screw should be adequate. Use a no.10 Yellow crimp fork connector or just wrap a solid conductor wire around the screw. Ground faults usually last only moments until the breaker actuates.


    Bookmark   May 10, 2012 at 10:37AM
Sign Up to comment
More Discussions
Refrigerator Water Valve Leaking
Any idea why the blue cap (see red arrow) on the water...
When should a boiler-warranty start?
We have a dispute with the company, that installed...
New Bertazzoni Induction Range?
I just saw a press release from Bertazzoni about a...
cancer warning on kitchenaid dw
New kitchenaid dishwasher manual has warnings for chemicals...
36" Rangetop & Wall Ovens vs. 48" Range
Our current kitchen plans call for a 36" rangetop...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™