Hi All,
I am building a mid-size powder coating oven to cure some parts until I can get time to build a larger one.

I have pulled the elements and harness from an the smaller side of a dual oven.
This gave me two 1500 Watt elements, power light, thermostat and safety thermostat all in one harness.
The oven was the old three wire hot - hot - neutral setup with the neutral (white) wire bussed to the steel cabinet of the oven.

The schematics I have for this side of the oven wiring have no connections to neutral but it does have one grey wire that joins with the black hot wire coming off the back of the thermostat control that attaches to an electronic control board. The neutral line only seems to make connections for the fluorescent light ballast, the internal oven lights, the oven door lock motor and the electronic control board. Should there be a connection into this portion of the oven wiring? There is a gray wire that couples with black coming off the thermostat control and plugs into the circuit board not shown in the diagram below.

Also, since I have to wire a plug/cord onto this I would like to upgrade with a 4 wire connection I have already wired my shop for.
Below is the portion of the wiring diagram dealing with the smaller oven side I pulled the parts and harness from. The black hot line is depicted on the left, the red hot line on the right and the white neutral on the outside right.
The grey wire mentioned above was the only one I had to cut loose from the rest of the harness, all other wires are separate.
If needed I can post the rest of the diagram, I am just trying to keep the file size down for the posting.

This 48352

Thanks.
Trent

Hi Trent,
I'll let others comment on your wiring questions as my first concern is are you aware of
the dangers of power coating operations? Have you or will you make your production available to your local construction office for their inspection?
I will appreciate your response...

I am building an oven 18" x 18" x 3' oven to cure parts larger than will fit into a toaster oven. This is not a commercial operation, just home small parts use.
If I need to do anything larger than will fit into this oven I can take it to a machine shop that has a walk in oven for large parts. Dangers for powder coating revolve primarily around chemicals used in part prep, ventilation during application and ventilation of fumes from the oven during curing. I am well aware of them.