Well I've spent several months reading responses to questions on here before deciding it was time to post a question of my own. Tkrussel, you should know that your no-nonsense direction and input has been very helpful to me during the last few months as I have been rewiring a cabin I purchased last year.

Here are my questions: What size wire do I need to use for a combined oven/cook top? It is an 8,800 watt, 120/240 volt, small apartment-sized oven with 4 burners on top. I think it is about 20 inches wide. I believe I will need to run a dedicated 40 amp circuit with #8 3-wire based on previous posts. Can someone tell me if that is correct?

donf

Most range/oven units conform to that spec. NEC code lists 40 amps for a range/oven unit.

Also by code, range tops are 30 amp and separate ovens are also 30 amps.

KeepItSimpleStupid

Nope: a #5 or larger copper wire, 4-wire circuit. Larger meaning #4, 3, 3, 1, etc.
40A breaker is correct.

donf

KISS,

Where did you get this info from? I'll append the Code section to this note when I get home. It's the 2008 version, but this section is unchanged from prior years.

Labor

Thanks for the prompt responses donf and KeepItSimpleStupid. I'll wait for a consensus or a definitive answer to develop regarding the wire size issue. The concern I now have is that the oven/cooktop says "three wire" on the back of it and KISS indicated that this will be a 4-wire circuit. KISS, are you counting the ground when you say "4-wire" (bare with me here as I am not an electrician and am not entirely familiar with the trade talk). Also, can I purchase the No. 5 in cable form (romex) or do I have to run conduit and pull each individual wire. Until now, I've only purchased cable in the following sizes 12-3 w/G, 12-2 w/G, 10-2, 14-2 w/G.

labman

#5?? In the past, they allowed dryers and ranges to use the same conductor for neutral and ground. I think you can run 8-3 with ground. Red and black to the hots, white to the neutral, and bare to the metal shell. Break the neutral to ground connection if it has one. Is this a built in, one piece unit?

Don't buy any wire yet.

KeepItSimpleStupid

Because of the 240/120 designation. I assumed a neutral. Ranges in the past did not use the neutral. Code, I think, dictates that 4 wire circuits should be used for new work.

So, check the connections available. You may have to remove a ground strap to utilize the safer 4-wire connection.

The terminology is 3 pole with ground.

It looks like your right #8 is OK.
The NEC code says to use 60 deg. ratings.
From: Engineering

The generic term for Romex is NM-B. Some NM-B cables are here: Dale Electric Supply Co. - Since 1947 - Wholesale and Retail Electrical Supplies

Stratmando

I think #5 wire may have meant be #6. I always pull 6's instead of #8's, you then choose 40 or 50 Amp Breaker, no repulling wires later. That would be 2 #6's for hots, a #8 for Neutral, and 10 for ground.

tkrussell

Minimum size circuit for a range is a 40 amp , that would use #8-3 Romex cable.

It will be called 3 wire, with a black, red, and white, but there is a fourth bare wire that intended to be the ground, and is understood, in the trade.

So, as long as your #8 cable has four wires, your fine.

Cobraguy

I would consider using #6 and going 50A for future upgrades. I have a double oven unit. I was a very happy camper to see my existing wiring was already set up for 50A because this unit required it.