Electric downdraft cooktop installation

[scotw]

I need to finish this project so I can get back to work on the garage!

I currently have a 18 year old JennAir electric downdraft cooktop which no longer works.

I intend to replace it with a Gas unit next year, but purchased a used GE electric downdraft cooktop (Model P389BJ1BB) to use until then. This weeks project is to install it before the holidays.

The current service is a 50 amp 2 conductor + ground 6 gauge aluminum wired directly into the cooktop (no junction box).

The new GE cooktop is 8KW.

The installation instructions are pretty vague (page 34).

http://products.geappliances.com/Ma.../Dispatcher?RequestType=PDF&Name=49-80387.pdf


Here are my questions:

1) What size junction box should I use?

2) What size wire should be used between junction box and cooktop? Is 10 ok or should I use 8?

3) I don't see any wire nuts at local stores that will work with 6 AL and 8 cu. How these connections usually made (polaris connectors?).

4) Does the grounds have to be connected to the junction box? In JennAir's instruction, they are not (page 11)

http://www.jennair.com/assets/product/JED4536WS_Installation Instruction_EN.pdf

5) I do I mechanically connect the grounds and neutrals together? Neutral + ground from the cooktop to ground from service and possibly ground from junction box.


Thanks,

Scott

 

[Stuart in MN]

The picture in step 7 of the instruction manual on page 33 indicates you can make electrical connections directly to the new cooktop. Is the existing wire long enough to reach?

Since your existing circuit is 3 wire, use step 10 of the instruction manual on page 34 for making electrical connections.

 

[scotw]

Step 3 of the instructions say to install a junction box, so I don't believe I can direct wire into the cooktop. I thought a junction box was also a code requirement. Thats what I mean about the vague instructions! I still need a safe way of attaching copper and aluminium wire together and how to handle the grounding of three large wires in the junction box.