1960’s house, 240 V service is 3-wire, with shared neutral and ground, and went only to clothes dryer receptacle.
Oven was gas, but I’m converting to electric, and extending wiring to a new box for it.
Oven has 4 wires, with separate ground and neutral. Should I splice both, or just the neutral, to the older shared ground/neutral wire?
Replies
"Oven has 4 wires, with separate ground and neutral. Should I splice both, or just the neutral, to the older shared ground/neutral wire?"
The installation instructions should show how to do with with either a 3 or 4 wire connection.
"1960's house, 240 V service is 3-wire, with shared neutral and ground, and went only to clothes dryer receptacle.
Oven was gas, but I'm converting to electric, and extending wiring to a new box for it."
While you are allowed to use EXISTING 3 wire installations when installig new appliances. But you aren't doing that.
You are running a NEW LINE for the oven. Since 1996 that has to be a 4 wire circuit.
And I am not clear on what you are doing. But you can't extend a dryer circuit to an oven. You can abondon the dryer circuit and covert it for use as an oven circuit, if the oven does not require over a 30 amp circuit and also if it is 4 wire.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
1960's house, 240 V service is 3-wire, with shared neutral and ground, and went only to clothes dryer receptacle
Are you certain the neutral and ground are shared? One common arrangement is to use a 3 wire circuit with two hots and a neutral, and to pick up the ground through a separate connection, typically a green wire to a water pipe. (note: this was legal in the 1960's, but is definitely not preferred for new construction now).
There are basically two types of 240 V circuits: those that use 240V only (e.g. a table saw) and use two hots and a ground (3 wire), and those that use both 120 V and 240 V and use two hots, a neutral, and a ground (4 wire). Both dryers and ranges are typically of the 4 wire variety, because they switch between 120 V and 240V for temperature control, etc.
Code allowed for stoves and dryer to be wired 3 wire connections, 2 hots and a neutral. And it allowed the appliance case to be bonded to the neutral. That was allowed for new installations for years until 1996. It is still in the code to allow new appliacnes to be connected to existing circuits.It did have some limitations. Basically it had to be wired directly off the main panel. IE, no mobile homes or apartments.And many locals had local amendments requiring 4 wire installation..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.