electric cooktop wiring


  #1  
Old 06-22-24, 02:04 PM
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electric cooktop wiring

I am replacing an old electric cooktop with a new one. The new cooktop manual says red wire connects to red wire and black wire connects to black wire. Upon upon the junction box I'm a little confused. See below picture of the current connection. The house was built 1980's so the color coding may not same as current. The black wire from old cooktop is connected to the brownish wire from the power supply (point A), the red wire from the old cooktop is connected to the black wire from the power supply (point B), the green wire from the old cooktop is connect to the bare wire from power supply (point C). There is a 4th wire from the power supply (point D) that is not been used.

Is the current connect correct? I used contactless voltage tester which shown both point A and point B have voltage while the cooktop is off.

Assuming the current connection is correct, then for the new cooktop, I should do the same as current connection, the black wire from cooktop goes to point A, the red wire from cooktop goes to point B and the bare wire from the cooktop goes to point C (with bare wire from power supply). Is this correct?

Thank you!




 
  #2  
Old 06-22-24, 03:17 PM
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A and B are the hots, C is the ground and D is the neutral.

Assuming the current connection is correct, then for the new cooktop, I should do the same as current connection, the black wire from cooktop goes to point A, the red wire from cooktop goes to point B and the bare wire from the cooktop goes to point C (with bare wire from power supply). Is this correct?
Correct. If the new cooktop only has 3 wires, and none of them are white, you will connect it as you described.
 
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Old 06-22-24, 03:19 PM
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Whether you connect black to black or black to red makes no difference. The white is neutral, which is not used for a 240V (only) appliance.
 
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Old 06-22-24, 03:26 PM
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Shouldn't he also connect the ground to the box to be safe?
 
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Old 06-22-24, 04:44 PM
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Technically the box is grounded via the metal cable but it couldn't hurt to connect the green to the box also.
It would be easiest to get a ground screw with green wire and then add it to the green splice.
Grounding pigtail.....
 
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Old 06-22-24, 07:52 PM
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Thanks for all the response. I also talked to a neighbor for this. We decided to follow the manual that black connects to black and red connects to red (according to Luke it doesn't matter in this case). The cooktop worked fine. Please let me know if this is not correct. Thanks all.
 

Last edited by fei2010; 06-22-24 at 10:17 PM.
  #7  
Old 06-23-24, 05:40 AM
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Greenfield is not a means to ground the box. A grounding conductor is needed and should connect to the box and any other grounds.
 
 

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