CONNECTION OF A NEW RANGE TO AN EXISTING RECEPTACLE

[Anonymous]

posted by: billlush (old forum transfer)
25 Aug 2002 04:36 pm

I recently removed an electric stove which was connected using a 220V 3-prong receptacle on a flexible cable, looks like maybe #8 or 10. The new stove is gas, but the oven is electric.
This new stove has a Romex pigtail with 4 wires. No problem so far.
BUT
The existing receptacle is aluminum wire, and the ground wire is not used in the 3-prong receptacle. This means the old stove (which is now gone, so I can't check) must have been ungrounded.
I would cut off the receptacle, and connect the new stove in a junction box (including the ground), but the problem is the aluminum. I can't fine CO/ALR approved connectors for such heavy wires. Max available looks like #12. So, my next idea, and the most convenient, was to purchase a new plug, and attach it to the Romex which comes out of the stove. This way, there is no direct CO to AL connection (it's done through the blades of the plug/receptacle), and I can also remove the plug whenever I need to move the stove.
The problem now is the ground wire. The way it is now, the stove is ungrounded, and I'm sure this is not the best situation. The question is this: can I connect the ground wire and the neutral wire (from the stove) inside the plug, and make the ground connection in this way? Or do you have another suggestion? I would hate to have to replace the AL cable all the way back to the box. By the way, all other wiring in the house is copper.

[Anonymous]

Posted by: Wgoodrich
25 Aug 2002 10:52 pm

Your post is a bit confusing. If you have two hots, a neutral and a ground in your existing branch circuit then you can just replace that three prong receptacle with a four prong receptacle and use all four wires in your existing branch circuit. Then install a four wire pigtail to the new range keeping the neutral and grounding conductors separated as a new range normally comes to you now.

If you have an existing branch circuit cable that it three wire with an insulated black, insulated white, and bare conductor then you must replace that existing branch circuit cable all the way from the panel to the range with a new four wire cable black, red, white, bare in that new cable installing a four prong receptacle as a new installation.

If you have an existing branch circuit cable that has a black red and bare then you have an SE cable and you are allowed to use this existing branch circuit cable with a three prong receptacle using a three wire pigtail no your range with a three prong plug. Then you must install a bonding jumper inside the range at the terminal block where your pigtail connects inside the range jumping from the silver screw of that terminal to the metal casing of your dryer where you have the green screw that the green wire was connected on your new four wire range cord that you removed to install the new three wire range cord. This wiring style is only allowed if you have an existing three wire branch circuit cable with either a black, red, white but no bare Romex cable or a black, red, bare but no white Service Entrance cable.

You must not do the above if your existing three wire branch circuit cable that does not have a black and red and bare conductor in that cable [se cable] but has a black and white and bare Romex cable. This romex cable using the white wire as a hot is not allowed to remain even as an existing branch circuit serving that range.

You must never jump the neutral wire in a branch circuit conductor to a grounding conductor anywhere in the house. This jumper is only allowed between the neutral and metal frame of a new range or dryer and only done inside that range or dryer and only if the existing branch circuit has an insulated neutral and two hots or a service entrance cable with a black red and bare. The neutral to frame connection must be inside the range at the terminal block to the metal frame of that range and only on an approved existing branch circuit cable discribed above.

By the way 8 awg and larger connections of a mixed copper and aluminum wires is normally done by using an alloy split bolt with an alloy divider keeping the copper and aluminum separate from touching each other. This type connection using a split bolt need both the thick filler tape to protect from damage and then the electrical tape.

Hope this helps

Wg