Wire for kitchen range

[petertay15]

Putting an electric range in the basement, about 10 feet from the breaker box. What amperage 220 breaker is needed? And what size wire goes to the receptor plug. Thanks, you guys.

[Mr_Mike]

Whatever the range installation manual requires. Most are 30 amp 220V, which would require 10/2 or 10/3 romex depending on whether a neutral is required. Read your range manual.

[R Clark]

...  Read your range manual.

+1.

I think there should also be an information plate that will identify the circuit needs.  I replaced an electric cooktop two years ago with a gas cooktop.  That old electric cooktop required a 40A circuit.

[MstrCarpenter]

I think your choice of ranges that use 30a or less is going to be quite small. 40 amps will open the field, but I would run 6ga romex which will handle 55a. (Good luck finding a 55 amp breaker though.) Here's why. The most common receptacles and cord caps are 15a for 14ga, 20a for 12ga, 30a for 10ga, and 50a for 6ga. That kind of makes running 8ga with 40 amps useless for a range because you can't put a 50a receptacle on the other end. If your range happens to come with a 40 amp cord cap, it better come with the matching receptacle because I doubt you'll find one easily.

[TDKPE]

Actually, NEC 210.21 and Table 210.21(b)(3) allow a 50A receptacle on a 40A circuit, especially since NEMA doesn't define a 40A receptacle or cap.

[MstrCarpenter]

Actually, NEC 210.21 and Table 210.21(b)(3) allow a 50A receptacle on a 40A circuit, especially since NEMA doesn't define a 40A receptacle or cap.

Tom, Not an argument here, especially for a range that will probably only see all the burners on high once a year, (like Thursday morning.) but isn't that contradictory to almost every other code relating to amperes and wire gauges?

[TDKPE]

Tom, Not an argument here, especially for a range that will probably only see all the burners on high once a year, (like Thursday morning.) but isn't that contradictory to almost every other code relating to amperes and wire gauges?

Welllllll, yes and no.  The relevant section allows a 50A receptacle on a 40A or 50A branch circuit, but the rules for sizing the range circuit conductors and overcurrent protection are separate.  So it amounts to using a 50A receptacle on a circuit sized for and protected at 40A.  It's just an oversized (capacity-wise) receptacle, which is perfectly safe, though it does allow one to plug in a load that requires a 50A circuit, so that's kind of not so good.  But that would violate other parts of the code which specify branch circuit and feeder ampacity, which must be met regardless of the load connection style (cord cap, hard-wired, etc.).  

And having said that, ranges and cooktops are a special case where you're allowed multiple taps from a 50A branch circuit to oven(s), cooktop, etc., of smaller conductor size (down to 20A ampacity, but kept short) than the 50A feeder would suggest, and ranges also can have a demand factor applied even when there's only one such load on the entire circuit (80% for a load not over 12kW rated).  

Circuits for welding machines are similar, based on duty-cycle and number of units, for the same reasons - load diversity where they're not likely to all be drawing max current simultaneously for any length of time, resulting in less conductor heating than if they were, and conductor heating is what drives most of the rules in the NEC governing circuit ampacity, including different conductor ampacities for the same gauge copper based on insulation and termination rating.  

For such a short run as the OP has, I'd just use whatever the installation manual recommends/requires, as long as it's not less than what the NEC requires, which isn't likely. In other words, even though the code may allow a lighter gauge conductor, for a short run there's no downside to just using 8-gauge copper for a 40A circuit or 6-gauge copper for a 50A since the cable/conductors aren't going to cost much no matter what.

[Cooler]

I was lucky when I installed my induction cooktop.

The wires leading to the cooktop were inadequate to operate the induction cooktop.  However the electrician found that only the first 4 feet of the wire was underspecified.  The balance was all good. 

So do look beyond the hookup wires and trace all the way to the junction box to make sure the wiring is up to capacity.

[Snipe Hunter]

The NEC is kinda funny with receptacles. From what I understand, all receptacles are de-rated. They can actually handle more than their rated load. For instance: receptacles over kitchen countertops are required to be fed by a 20 amp breaker and 12/2 (20 amp romex). But 15 amp receptacles are acceptable. The rating for the receptacle has more to do with the configuration of the slots than the load.

Btw, I don't think ranges or ovens are manufactured for 2 wire connections anymore. I had to run all new wire for our new kitchen appliances, all 3 conductor. Also, they had to be hardwired per mfg's specs. No plugs