Doing a kitchen remodel and the new oven calls out for a 240/208 40 amp outlet. The existing outlet is 240/208 50 amps.
I think all I have to do is swap out the 50 amp dual pole breaker and replace it with a 40 amp dual pole breaker and I should be good to go. I’m guessing that the oven cord will fit the existing 50 amp outlet-I didn’t see any 40 amp outlets at the store, only 30 and 50 amp ones.
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Replies
Replacing outlet
There is no need to replace the breaker. The breaker is based on the wire size rather than the outlet. Since the existing is 50A leave it. You can use either a 40A outlet and plug or a 50A. Obviously they have to match. It's possible that the old circuit is 2 wire plus ground. And that the new range requires 3 wire plus ground. Since this is a retrofit you don't need to redo the circuit. Put a plug on the new range to match the existing outlet and wire the neutral and ground together on the range.
replacing outlet
"There is no need to replace the breaker. The breaker is based on the wire size rather than the outlet. Since the existing is 50A leave it. You can use either a 40A outlet and plug or a 50A. Obviously they have to match. It's possible that the old circuit is 2 wire plus ground. And that the new range requires 3 wire plus ground. Since this is a retrofit you don't need to redo the circuit. Put a plug on the new range to match the existing outlet and wire the neutral and ground together on the range."
Just trying to deconstruct this:
No need to replace the breaker. Wouldn't you need a 40 amp breaker, if that what the specs are calling for, otherwise the possiblility of "overload" could happen and resulting mayhem would ensue.
Is wiring the neutral and ground together a normal thing, and is that code? I wired a kiln recently that had only 2 hots and a ground, no neutral-is this the same premise? If I recall correctly the one hot acts as a "neutral" and the other hot as a hot, and they go back and forth in rhythm to the beat of the AC current.
The current outlet has holes for 3 prongs plus a ground-so I should be covered.
I don't have the oven/stove yet onsite, I imagine all current units come with a "whip" that has 2 hots, 1 neutral and a ground wire.
Thx.
You need to read the install instructions for the stove (probably you can find them online). If it says it needs a 40A circuit then you're good with the 50. If it says it must be "protected" by a 40A breaker then you need a 40A breaker.
Breakers protect the wire, not the appliance, so yes, a 40 amp breaker will protect #6 wire that is rated for 50 amps, but it is not neccessary to switch it out. If an appliance must be protected by a specific size breaker or fuse it should be internal to the appliance or at a disconnect readily available and locatednear the appliance. The later being for hard wired commercial equipment. Most cord connected appliances do not require that level of protection.
A 40 amp stove going over current on a 50 amp circuit will not trip the breaker unless it iscaused by a short to ground. The ussual failure in electric ovens is when the elements burn open and even on a 50 amp appliance that does not always result in the breaker tripping.
He is safe doing either.
Neutral to ground
Many 240v appliances have very small 120v loads. (The timer motor on a dryer is 120v as are clocks lights etc on ranges) Some time around 25 years ago a seperate neutral and ground became code. Prior to that they could share the same wire. The code does not require that you rewire existing installations.So newer appliances can be connected to existing circuits. If your current (no pun intended) installation is 3 wires + ground then it is fairly recent. Use a 3 wire + ground outlet or hard wire the range. I've never seen an appliance that depended on a circuit breaker for internal protection. Circuit breakers are to protect the premises wiring.