What is the gauge rating of the four wires for a four pin oven pigtail

[CJ]

I bought a four wire electric oven pigtail (two hots, a neutral and a ground) and was wondering what the gauge rating for each of the four wires should be?

[Dave Martindale]

The two hots and neutral should be whatever is appropriate for a 40 A circuit, probably 8 gauge copper. I don't know if the ground can be smaller.

Dave

[CJ]

The oven is on a 50 AMP circuit, so is 8 gauge enough. the next one up would be 6 gauge?

[Doug Miller]

It can. So can the neutral, for that matter, since the heating elements are

240V and don't use the neutral at all. The neutral wire is used for the control circuits, ignitors, lights, fan (if there is one), etc. which are all 120V, but the total load of all that won't be more than 5 amps or so.

Yes, the next size up is 6 gauge, but it's doubtful that you need that. Check the rating plate on the oven, and match the pigtail to that (not the the breaker rating).

[Nathan]

WHOA, don't listen to this guy, that is crap!

50 amps usually call for 6 gauge wire, in a short run like is used for a stove, you could probably get by with 8 gauge, but I would stick with 6 gauge...just go to Home Depot or Lowes and buy one.

The ground wire can usually be 1 gauge below the other wires. It is really only there for safety, if you get a short it can follow the ground path instead of a person.

The neutral is the return path, it has to be the same guage. If you have two hots that are the same phase, then the neutral would have to be up a gauge...but that won't happen. They are always opposite phase by approximately 180 degrees and therefore partially cancel each other out.

If you look in your main breaker, the neutral and ground buses are tied to eachother.

Think of the voltage/current like water. It flows in through your hot wire, then into your appliances, then back through the neutral line and into the ground.

[Mike Hartigan]

But that's not the case with the 240V heating elements - the heavy hitters in an electric range. They don't use the neutral for return. As Doug correctly stated, the neutral is used only for the electronics, lights, fan, etc. And since 120V outlets on ranges have gone the way of cigarette lighters in cars, the maximum current that the neutral will see is predictable. Indeed, Thermador specifies 10 for the hots, 12 for neutral and 10 for ground for their dual fuel ranges (although I'm not sure why ground needs to be 10, in this case).

[Doug Miller]

The only "crap" here is your post -- you don't understand how 240V circuits work.

According to the National Electrical Code, 8 gauge wire with 75 deg or 90 deg insulation is rated at 50 and 55 amps, respectively. [2005 NEC, Table 310-16]

Furthermore, just because the *circuit* is 50A, that does not mean he needs a

50A pigtail -- if the oven only draws 38A, say, at full load, a 40A-rated pigtail will be just fine.

False.

Per the National Electrical Code, for circuits rated 30A and less, the grounding conductor must be the _same_size_ as the circuit conductors. Circuits of 40 to 60 amps may use 10 gauge copper grounding conductors. Above

60A, the grounding conductor may be as much as *four* gauge sizes smaller than the circuit conductors. [2005 NEC, Table 120.122]

True, but not relevant to conductor sizing.

True for 120V loads, but not true for 240V loads. Go back to school, Nathan. You don't understand 240V wiring.

No, they *completely* cancel each other out. Go back to school, Nathan. You don't understand 240V wiring.

In a combined 240V/120V load such as an electric stove, the only current flowing in the neutral wire is the unbalanced current between the two hot legs; that is, the current drawn by the 120V loads. The 240V loads don't even need the neutral at all.

And that's relevant here exactly how?

True for 120V loads. *Not* true for 240V loads.

You really need to read up on this a bit, Nathan. Trying to correct other people's "mistakes" works a lot better when you understand the subject yourself -- and you clearly do not.

[Doug Miller]

If it's a 30A circuit (as implied by the use of 10ga hots), the NEC does not permit the ground to be any smaller than 10ga. [2005 NEC, Table 120.122]

[Nathan]

I stand corrected. Sorry Doug. I was thinking standard 120/240 V circuits. I have never dealt with straight out 240V.

I was stating the gauge for longer runs, like a house to a garage...forgot the topic is for something soo short.

[Doug Miller]

Thank you.

[Dave Martindale]

Are you sure it's really 50 amp? Around here (BC Canada), normal electric range circuits have 40 A breakers and 40 A wiring, even though the socket used is rated for 50 A.

What size is the breaker in the panel, and the wiring in the wall?

Dave