New Oven Build

[frankle8]

Hi everyone, I have been reading alot here. So much info, it can get a little confusing for a newbie! But, I'm forging ahead with a oven build, but I have a couple of questions. 1st off, the oven I am building is a 3'Dx4'Wx7'T (OS Deminsion), actual inside deminsion is 32"Dx40"Wx72"T. I will be using 4-2900W Elements which according to the calc. will be approx 48amps. I will be using a tet-612 controller, and a clion 60 amp relay, with a Dayton #1TDU9 fan, the oven will have 2 40 watt lights . The wiring diagram I will use is one I printed of from a post by Ed. I have one question concerning the relay. I have seen many heatsinks for the lower rated relays, i.e. 25a and 40a, but none for a 60a relay. Where have you guys been purchasing yours from and is there a certain model that works better than the others? Also, I would like to include a timer in the wiring diagram of Ed's, but, I would not know how to hook this up. Any help on the timer and heatsink would be greatly appricated.

This site is great and is very helpful to all. Great job everyone. Keep up the good work!!

[ed_denu]

It looks like you're off to a good start.

An option for the heat sink is to use a computer cpu heatsink with fan. This is what I use for my oven and I've had no problems. It will require that you furnish a small 12VDC power source to drive the fan. Make sure you also use a thermal pasta between the heatsink and SSR. These units can be salvaged from any older PC or found online for minimal $$$$, much less than a good heatsink would cost.

As for a timer I use a spring wound timer from McMaster Carr, model 7014K4. The timer has no input power requirements and would be mounted in the '+' side of the circuit between the pid and ssr. The timer has a manual override setting which you would enable when starting the oven. Once the parts have reached curing temperature you turn the timer to the desired time duration and the circuit will be broken when the time elapses. Another option would be to use a better PID like some of the Watlow's that have built-in timer capabilities.

[duke46]

Looks like you are wanting to use a SSR relay and most guys don't some companies do. But from what I have heard they can go down on you?

I would put in two of these. One for each set of elements. No heat sink needed.
Contactor, 2 pole 40 A [CN-PBC402-120V] - $13.80 : auberins.com, Temperature control solutions for home and industry
and also buy the right controller for this type.
1/16 DIN PID Temperature Controller (Relay Output) [SYL-2342] - $44.50 : auberins.com, Temperature control solutions for home and industry

Install two switches and if you want to cut either set of burners off you can and also if you want to just mess with your controller and not have them come on you can.

I stay on another forum all the time so not sure what is going on here on building ovens. But if you need more info just pm me an I will try to find some post on building one on it.

Not sure if I can post a link to it here or not? Some forum's don't like it a delete your post?

[duke46]

This timer you can set for the amount of time but it is a pain to learn because I have one but I use it for the ramp soak that it is made for.

PID Temperature Controller w/ Ramp/Soak (Relay Output) [SYL-2342P] - $89.95 : auberins.com, Temperature control solutions for home and industry

Remember you are not baking a cake so you just can't cut your oven on and get it to temp and then stick in your coated part and say bake for 10 to 20 min. That is done only on a line that is doing the same parts over and over and they know how long it takes to cure the powder.

Just get a kitchen timer that you can set when the part gets to the correct temp by using an IR gun or a clamp on thermocouple like I use that is connected to an alarm and then you set your timer and clip it on and walk away.

[frankle8]

Ed and Duke,
thanks for the input. I know there will be more questions as I go along, and it's good to know that everybody is so willing to help out.

I think I will stay with the ssr for now and hook up the heatsink and fan. I do have an old computer here that is basiclly dead, and I will pull it out of that. Ed, you stated that I will need a 12vdc power supply. Can you suggest any particular kind? Or, can I just wire in series replaceable batteries to get the 12 volts? Would rather not go the battery route unless I have too.

As I get further along will posts some pics. Thanks again guys.

[ed_denu]

Just look for an old plug-in wall transformer, the kind that are used for cell phones or any rechargeable device. If you don't have one lying around, they can be found on ebay for a few $. A slightly lower voltage model would probably also work, it just may not run the fan with as many rpm's.

Something like this:

http://cgi.ebay.com/SECURITY-SYSTEM-...3%3A1|294%3A50

When you build your control box, just add a 120vac receptacle for the transformer.

[frankle8]

Thanks again Ed. I just happen to have one of them lying around also!