Wiring Oven

[TemperanceCoaters]

Ok, heres the deal. Me and my buddy have been powdercoating for a while now but keep running into some trouble here and there. And i finally found a good site to come to. I will post some pics of our oven a little later today after i wake up.
But, on to the dilemma. We have a kitchen oven next to our homemade oven. We switch back and forth between the two ovens depending on parts. Our large oven is 6x4x3 in feet that is. We have 4 elements mounted into our oven, but we dont use all 4 because we dont think our oven can handle it. Is there a better way of hooking the elements up? Right now we just take the wires out of the back of the small oven and hook them up to the elements in our large oven. Is there thermostats and what not we can buy so we dont need to switch back and forth?
Any info would help out.

http://www.powdercoatoven.4t.com/construction%20page.html

That guy has a nice picture of wiring but i dont know what a definite purpose contactor is.
Any help is appreciated and ill get pics later today.
Heres one i found


Now our oven is vertical and has a rack on wheels.

[Crimson]

Re: Wiring Oven




The Contactor

http://www.famousparts.com/c25bnf240aco.html

[jrow]

Re: Wiring Oven

TemperanceCoaters,

The contactor is a 240V switch activated by a 120V source. The "S" in the diagram activates the contactor. By the way thats a real good price for a contactor.
If you can got to an 'electrical contractor vendor' and look at a contactor like the one that he used, it will become self explanitory!

I think Gary Brady should be complemented on his drawings and the construction of his oven. It's a real bute.


John

[TemperanceCoaters]

Re: Wiring Oven

Ok, the one you showed me is 40 amps but 120 coil? Dont we want it set up on 220 for out oven? Im gonna go get pics of the oven right now and post em up so you guys can help me a little more.

PS, im 19 and have no electrical background, i dont understand that drawing either.

[cdaeme]

Re: Wiring Oven

The Contactor
http://www.famousparts.com/c25bnf240aco.html

I'm no electrician so if I am not 100% correct someone please chime in. If you can print off the diagram so you can follow the connections as I explain them.

If you look at the drawings. L1, L2, N, G. is your incoming power. 220v power is comprised of 2 110v lines a neutral wire and a ground. Lets focus on L1 first its 110v and it branches off, one wire goes directly to the (C) contactor and the other goes to the (S) switch (This will be your on/off switch) then to the (T) thermostat (temperature control) then to the coil on the contactor. This part of the circuit works like this - You have 110v to the Switch when you turn the switch on it now flows 110v to the thermostat if the temperature is below the thermostat setting then the 110v flows to the contactor coil which will engage the coil (more on this in a minute). When the temperature reaches the setting on the thermostat the thermostat will break contact and no longer sent 110v to the coil as the temperature drops below the thermostat setting it will make contact again energizing the coil again.

Now for the contactor as you can see L1 and L2 go directly through the contactor and out the other side. On the inside of the contactor the circuit is not made until the coil is engauged (in other words the connection is broke inside until the coil is engauged). When the coil is engauged you now have 110v on L1 and L2 going to your elements. L1 should go to one side of each element and L2 to the other.

The (N) neutral completes the 110v circuit for the coil which works like a magnent with 110v it will pull the contacts into place and complete the circuit for L1 & L2 through the contactor.

The (G) ground is for your protection if something with voltage shorts out or makes contact with the frame it will trip the breaker. Without the ground if something shorted you might not know it until you touched the oven and suddenly became the ground. (This is not fun!!)

The connections on the elements should be self explanitory if not let me know and I will try to help with them also.

It's good to see young people taking some innitative. Take your business seriously be honest and always wear the white hat and you will go far. If you would like to contact me directly contact info is on my site.


Jason Williams

https://www.autocyclepc.com

[TemperanceCoaters]

Re: Wiring Oven

Thanks, that helped alot. Will that contactor shown work? If so im going to order it. Also, how do i figure out how much power my elements are pulling. Im uploading pics of the oven right now.

Heres the pics of the oven.



It was made out of 2" Insulated sheet metal with a concrete like finish on the inside. Works very nicely and we dont lose very much heat.

And we do take this seriously, me and my buddy hope to open up an actual shop and do this for a living.

[cdaeme]

Re: Wiring Oven

The amperage draw goes a little above what I can explain but if you will do a forum search for element size or amperage you should get some posts that have discussed that alraedy. I will look myself and if I find them I will post some links. I too am just getting started and hope to expand into a full shop of my own. I'm 34 now and only wish I had started something like this at 19..


Jason

[cdaeme]

Re: Wiring Oven

About halfway down this thread is the formula you need. http://forum.caswellplating.com/show...t=element+size With 4 elements you will probably need a 60 amp breaker and the contactor will need to be 60 amps also for that price on a contactor you could probably buy two and separatly wire 2 of the elements on another switch. That would give you the option to only run 2 elements if you want. Nice oven buy the way I wish I had one that size already!!.

Jason

[pickleboy]

Re: Wiring Oven

oven looks good for starters my only concern is the mismatched elements. this may be a concern. generally speaking the shape has to do with the design of the original oven they came from. what i am trying to say here is they may not all be the same wattage/ heat range. if this is the case it could cause hot spots in the oven. example: if they were numbered top to bottom left to right, then lets say that 1 is 500 watts, 2 is 400 watts, 3 is 750 watts, and 4 is 600 watts. there might be a time that parts closer to element 3 cure faster or more than parts next to element 2. this can also cause a issue if you wire them in 2 circuits, the circuits should be balanced if/when possible to insure even current flow through the contactors. in the example of 2 circuits running from a 60 amp supply, it should be 2 30 amp sides and not a 40/20 split. i hope this makes sense. also please dont take offense i think you have done a great job so far. i would wire it up and try it out. if you can get a amp probe to test the circuit draw this will help. also when you fire it up for the first time put some scrap metal in the oven at different locations(preferable the same size and material scrap metal. bring them up to temp and check each part with a laser thermometer to see if you have hot spots. i also lastly would think about a fan for circulation.

[TemperanceCoaters]

Re: Wiring Oven

Yea, the elements are out of 4 different ovens, never really thought about the different power levels. Also we had a fan in there but it wasnt made for heat and partially melted causing it to wobble. The oven holds the heat very well, the outside is only 10-15 degrees warmer than the air temp of the shop.

So is there a place that i can buy 4 new elements? Is 4 elements enough for our oven?

[TemperanceCoaters]

Re: Wiring Oven

Ok, looked around a little bit and found this link

http://www.emeraldelectronic.com/store/proddetail.cfm/ItemID/15481/CategoryID/2501/SubCatID/46/file.htm

Those elements are 3100W, how many would i need to efficently heat up my oven? Also, should i order that contactor or look into two of them? But i think we only have one 220 plug in the shop.

Ive gotten more info on this site then searching for the past year, lol.

[cdaeme]

Re: Wiring Oven

Ok here are your choices. The elements in the link are 3100 watts so:

3100w X 3 elements = 9300w/240v= 38.75amps
3100w X 4 elements = 12400w/240v= 51.6amps

Using 2400w elements
2400w X 3 elements = 7200w/240= 30amps
2400w X 4 elements = 9600w/240= 40amps

From the above senairos you have two good choices

3100w X 4 elements = 12400w/240v= 51.6amps
Use two of the 40amp contactors as discussed earlier and order 4 matching elements.

2400w X 3 elements = 7200w/240= 30amps
Use one of the 40amp contactors and get 3 matching elements.

You should also be looking at a vent hole and a fan for even heat circulation.

If you decide to go with the two contactor design let me know and I will take some time later tonight to modify the schematic for the additional contactor (you will use the same 220v service). This will probably be the design I use when I build my oven. The switches and temp controler/ thermostat could be used from a donor oven.

This is a great site for info. Thanks to Caswell for providing it for us.

Jason

https://www.autocyclepc.com

[TemperanceCoaters]

Re: Wiring Oven

Ok, well im gonna have to figure out how big of a breaker we have in the shop right now, im not quite sure.
If i get 4 of those elements at 3100 will i need a 60 amp breaker? Just to have a little extra?
Or will 3 elements at 3100 heat the oven up quick enough?
Also, will we need two lines of 220 ran to run two contactors? Becuase i dont think the shop can handle that much power draw.

Im thinking that it might work out better for us to run 3 elements at 2400, use the one 40 amp contactor shown.

Also what is the difference in 1 pole, 2 pole, 3 pole, 4 pole contactors?

[TemperanceCoaters]

Re: Wiring Oven

Ok, the workshop has a 50 amp breaker, i think thats as big as it can go. So im thinking we should run 4 2400 watt elements, these http://www.emeraldelectronic.com/sto...ID/46/file.htm
So, according to your math that will be 40 amps, so would i be able to use one 40 amp contactor?
So onto the contactor, the one posted here is a 40 Amps, 2 Poles, 120 Coil Voltage, but there is one Contactor, 40 Amps, 2 Poles, 208/240 Coil Voltage. Wouldnt i need the 208/240 one?

Onto the vent and the fan. How do you guys hook up fans inside the oven? And what kind of vent do i need that wont let a lot of the heat out?

[cdaeme]

Re: Wiring Oven

Ok with all the new info you have given I am going to make a recomendation. If this was my situation and oven I would buy three of these http://www.emeraldelectronic.com/sto...ID/46/file.htm and this contactor http://www.famousparts.com/c25bnf240aco.html. The 50amp breaker tells us more about what we need to know with the 10% buffer needed this means the max you need to use on this circuit is 45amps. The three 2700w elements will be a draw of 33.5amps which will work with the 40amp contactor. The max draw for the 40amp contactor with the 10% factor will be 36amps which will still allow room for the draw of the fan motor.

Do you have the switch and thermostat?

You only need the 240v contactor with the 110v coil we will only be applying 110v to the coil to engauge it so the 240v can flow through to to the elements.

If you used the two contactor design you would only need the single 220v source you currently have the contactors would be wired to the internal workings of the oven circuit.

You will only need the two pole contactor because we are only running L1 & L2 through it.

Now the fan. Check out these links this is similar to what you need - http://forum.caswellplating.com/phot...0&ppuser=11900

http://forum.caswellplating.com/photopost/showphoto.php?photo=558&cat=500&ppuser=11900

http://forum.caswellplating.com/photopost/showphoto.php?photo=557&cat=500&ppuser=11900

A normal household oven has a 2-3 inch vent hole that vents up through one of the top eyes something like that should be sufficient.

Wew!! I think that answered them all.

Jason

https://www.autocyclepc.com