Oven Building

sinr98 · 09-13-2008, 01:50 AM

Hi everyone. I am gathering info and parts to build a powder coating oven. The oven is 4'w x 4d x 8't. The oven is made out of galvinized framing studs, with galvinized interior sheets, 3.5" of mineral wool insulation. I have purchased 4 elements for the oven rated at 5000 watts each at 240v. The only part i'm not sure of is the temperature controller and contactor or SSR combination I will need. The main power is a twin pole 60 amp breaker. I need the oven to stay at 400 deg for 30 mins or so and be able to get as hot as 450 deg. Any help on this is appreciated.

frenchelectrican · 09-13-2008, 02:51 AM

There are few issue that it will need your attetion here

• 4 X 5000 watt heating elements = 20,000 watts

• 20,000 watts at 240 volts = 83.33 amps

• 60 amp breaker will handle only 14,400 watts max

So that those item need some change if you are planning using the 60 amp circuit but for the rest of other stuff I will let other guys chime in with few idea along the way.

Merci,Marc

wire_twister · 09-13-2008, 08:09 AM

Sinr98,

For temp. control I would use either a Honeywell chart recorder or a UDC3000 controller and RTD. Both of these will allow you to ramp up to temp, hold, and ramp down if needed. We used alot of these in a plant I worked in to control some ovens and steam dryers, in fact I have several UDC controlers and instruction books and maybe even an RTD. If you decide to go this way pm or e-mail me and we can talk about it. Marc is right on with the electrical requirements, you will need a circuit with more ampacity to carry your heaters. Also you will need 1 large (NEMA 2 or 3) contactor, or 2 smaller (NEMA 1) contactors to control the heat.

sinr98 · 09-14-2008, 12:43 AM

Thanks for your help guys. I am aware that I can't run all four elements on the 60 amp circuit. I forgot to mention that out of the four I was only going to use two which would bring me to 10000 watts. I thought about using three but I don't want to over load the breakers. I just hope that 10000 watts will be enough to heat the oven and keep the oven in about 15 mins or so. If I do run two of these elements, and got two more elements at say 2000 watts each to bring me up to 14000 watts, would I still be able to run a single controller? I am guessing that I would have to use two seperate contactors. One for each set of elements. Thanks again for your help guys.