Electrical Wiring
GBA Editor
| Posted in Mechanicals on
I am wiring a double electric oven that is equipped with 10 guage wire factory installed. The spec plate indicates it is rated at 7800 watts. Can I use 10 guage wire to run 240 v wiring to the electrical box. My electrical book says I need to use 8 guage – isn’t that overkill since the stove only has 10 guage?
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Replies
Kellye,
The longer the wire, the greater the resistance and the greater the voltage drop.
Running 30 feet (or 100 feet) of cable from your electrical panel to your oven obviously requires a thicker-gauge cable than is required for the 1 or 2 feet inside the appliance (or the cable used for the cord that runs from the receptacle to the applicance).
if you are unsure of what size cable to run, it's definitely time to call an electrician. Most building codes require such work to be performed by a licensed electrician -- for good reasons.
Sorry Kellye,
I could not resist quoting from an old movie
1983 ....Mr. Mom starring Michael Keaton as Jack
Ron: [about rewiring the house] Yeah? Are you gonna make it all 220?
Jack: Yeah. 220... 221, whatever it takes.
Kellye,
10g copper wire is rated for 30 amps. If your oven is rated at 7800 W @ 240 volts, that is a current draw of 32.5 amps (7800/240 = 32.5). That requires 8g conductors.
That's a good one John....221, whatever it takes. I haven't seen the movie but now you have my curiosity up.
Martin and Robert, thank you. Your information is helpful and we now know exactly what we need to do.
Kellye,
Make sure you really do "know exactly what you need to do", which is to hire a competent licensed electrician to do this work safely.
Some ovens require 4-wire connections, some only 3-wire. Some require both 240V and 120V power, which needs two current-carrying conductors, one common conductor and one grounding conductor. Some appliances must be bonded to ground at the carcass.
It's not worth making a mistake with wiring. I could result in a home fire or death by electrocution.
Robert, I appreciate your words of caution. Can you tell me, does it make a difference if you use solid or stranded wire?
Kellye,
I may know more about electricity than you do and I know enough to hire an electrician.
That was the point of my "Mr Mom" humor
Kellye,
No. The ampacity of a cable is determined by the type of metal (copper vs aluminum), the type of insulating jacket (thermoplastic vs thermoset), the temperature rating, and the gauge.
Conductors larger than 10g are generally stranded because they would be unmanageable if solid, but the total cross-sectional area of metal is the same and hence the ampacity.
But the fact that you're continuing to ask questions that indicate your lack of experience with electrical matters deepens my concern. You should contact an electrician.