How many elements can I use?

[4birdman]

I'm planning out my oven build, but I'm not sure how far I can go. I want to build a large one, but I realize that isn't gonna happen in my current shop.

My shop is currently almost maxed out as far as power goes, since it is attached to my house and I don't want to bother having a subpanel run since I will hopefully be moving to a bigger shop in the next few years.

So, the size of my oven will basically be dictated by how many elements I can throw in this sucker.

I currently have a 30 amp breaker on a standard household 220 outlet running my current household oven.

I'd like to build an oven that is 7'x3'x2' inside dimensions to fit the spot I have in the shop. I want to run two elements, one at the top and one at the bottom and be able to run the top one independent of the bottom one so I can partition it in half and only use one element if I only need half the oven size.

Would two elements work in an oven this size, or would it be better to have three? I plan to run a fan to get some heat to the center of the oven, or would this even be necessary with an oven this size and with a top and bottom elements?

Any advice?

[ed_denu]

You're limitation is going to be the 30 amp circuit you have available. You're probably looking at around 5800 watts maximum.

80% of maximum load is a good target so: 30 Amps * .8 = 24 amps max

24(amps) * 240(volts) = 5760 watts

How you divide the watts between 2 or 3 elements may depend on how you design the oven. I think you can get good heating results with your planned size of oven(42 sq ft).

IMO a recirculating or a convection fan always helps.