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Glass cooktop wiring

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dborns

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I have a four burner cooktop in my kitchen. We just had the countertops replaced and the guys disconnected the cooktop to install the new counter. They didn’t tell me which wires went to which, and from what I’ve seen on the net, it’s not how I think it should be.
So the outlet box on the wall has three wires; red, black, white, and ground.
The cooktop only has three wires; red, black, and green.
The guys put the wire nuts and romex connector in the box, and there were only three wire nuts, so I’m guessing the ground from the house gets wrapped around one of the screws on the outlet box, but what about the others?
Thanks in advance.
 

afjes_2016

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They should have reconnected it for you since they disconnected it.

Anyway, you say you have three wires in the box but tell us four wires. Please confirm.

Do you have a make and model# of the cook-top to give us. It may be a 240v according to what you describe but we need to be sure. Colors of wires do not always tell the complete story.

Can you take a clear picture of the inside of the box (if you feel comfortable doing it and you know the breaker is off)..

Also, the cook top should have a metal name plate on it somewhere telling the electrical specs. Can you take a picture of this metal name plate.
do you know for sure which circuit breaker poweres this cook-top. If so is it a two pole etc, what is the number stamped on the breaker handle.
 

dborns

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Hello. Thanks for the reply.
I have three wires from the cooktop; black, red, and green. I have four wires in the outlet box; red, black, white, and ground. Sorry, I noticed my incorrect info in the first post.
There are no markings as far as model number, but it is a JennAir. It’s on two 30 amp breakers.
There is a wiring diagram, but I might as well be reading japanese.....
I’ll try to post pics again, because when I did, it showed “security error”, and wouldn’t let me.
 

dborns

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And there isn’t a metal plate with electrical details, or product info anywhere. Just a sticker showing power usage rating.
 

dborns

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I actually found a model and serial number. Maytag, model JED8430ADB. I’ll start looking for an installation guide online.
Even then, I don’t know how to see what the other wires are in the outlet box. I have a tester for 120 outlets, but I’ve never messed with anything more powerful.
 

bud16415

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If you look on your wire schematic it shows BRW and the end of your conduit you have BRG. My guess is if you go to the other end of the conduit where those wires are connected to the unit you will find the green connected to the screw marked W.



If you feel comfortable checking the voltages at your Jbox you need to make sure the wires are out in the air like you show in the picture, make sure no one is going to mess with them after you turn the power on and then you should measure 120v or there about between the W&R and also the W&B. You should also measure 120v between Ground&R and Ground&B. between R&B you should see around 240v. Make sure your meter is set to a range that is higher than 240v.



The white would in that case connect to the Green wire. The ground if the unit provided a ground connection to the frame could be connected there with another wire, but seeing as how it wasn’t my guess is there isn’t a ground connection.



Another thing you can look at for a clue is the wires in the Jbox to see what ones looked like they had been wire-nut. You should see where the wire nut has scraped up the insulation or even the wire.

I’m not a pro and I’m sure the pro will be back with more advice.
 

kok328

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red to red, black to black, or red to black, doesn't matter. green to white, copper to box.
should be connect to a double pole 30A breaker (which I believe your have) not (2) 30A breakers.
 

dborns

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Ok, I’ll give that a try. And sorry for the numerous incorrect info. It is on a double pole 30 amp breaker, not two as I stated.
 

Eddie_T

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If the conduit is plastic I am surprised that the cook top frame isn't grounded for safety. However it appears that the white wire (neutral) is bonded to the frame at the fan receptacle per the schematic thus making it a three wire system.

My Jenn Air is an older model (not glass top) and I wired it with SE cable so neutral and ground are the same and the pilot light and the fan are the only things that use 120v and the grounded neutral.
 
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dborns

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I temporarily wired it as kok328 suggested, and all burners worked along with the fan. I had to leave, so I turned the breaker off until I can wire it correctly and be home in case there’s an issue.

Eddie, the conduit is plastic, and you’re correct it’s not grounded. If I can reach the wiring box on the cooktop, I’ll open it and see if someone took a shortcut and cut the ground wire for some reason...
 

Eddie_T

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Just try a voltage reading from the hot side of a nearby receptacle to the cook top metal housing. If you get 120v the metal is grounded through the neutral which isn't switched by the breaker.
 

WyrTwister

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Think I am hearing , the junction box on the wall contains a bare earth ground , a red , a black and a white . The " whip " from the appliance contains all of those , except the white .

White is suppose to be neutral . Your appliance is 240 VAC , single phase and there is evidently no 120 VAC load . So the white neutral is not needed and should be " capped off " with a wire nut . The red to red , the black to black and the green to the bare earth ground .

Simple , no sweat .

Best of luck to you .

God bless
Wyr
 

Eddie_T

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There are 120v loads (the fan and the indicator lights) so the neutral is required. However the neutral may bonded to the housing at the fan receptacle. See post #12 for easy way to test.
 

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