My oven SCHEMATIC...for new oven builders..

[RNMHRD]

I believe you, but it must be drawing neutral from the grounded oven.

You guys are right on the schematic, i forgot to draw in the Neutral ground strap that goes from the center lug to the box.. Here's a updated pic...lol

[kcenicola]

In older houses, the Neutral and The ground wires are all tied to to the same terminal strip back at the main box. In newer houses the grounds are tied to a terminal that goes to a spike in the earth and the Neutral's go back to the telephone pole outside your house.

The problem with the older setup is that when people are wiring a 240V circuit and they only have 3 wires to connect to their device, they don't take the time to ground their device to the Neutral. So if there is ever a short circuit between one of the 120V hot legs and the device (oven) the oven becomes charged an becomes a shock hazard. If the oven is attached to the Neutral, if there is ever a short between the oven and one of the hot legs, the circuit breaker will trip.

When they changed 240V receptacles to have 4 wires, this forced people to attach the green ground wire to your device to protect against this.

KC

[Mick40]

If anyone is intimidated about building their own controller then they should contact Ken. The controller in the picture was built for me and I have to say it's a work of art and cut down my oven build time significantly. Not to mention, I could have never built anything close to that with all the features. Individual switches for the light, fan and can run one or two elements. I wanted an amp meter because my shop is a long way from the house and the oven runs off a generator. Ken suggested a nifty digital controller that will keep the oven at the exact temperature each and every time. Within the next week I should be ready to fire it up. Anyone looking to use Ken's services I can't say enough good things about him and the quality of his work. Very professional, had a lot of great ideas and incorporated everything I wanted. I have never met Ken in person nor have I ever had any dealings with in prior to this. Honest, trustworthy and knowledgeable, what more can you want?

Thank again Ken,

Mick

[mtumbleson]

You guys are right on the schematic, i forgot to draw in the Neutral ground strap that goes from the center lug to the box.. Here's a updated pic...lol

I have a question about the gauge of wire needed to use this wiring schematic for the elements. When wiring elements together this way, do you need to add the amp draw for ALL the elements to determine wire gauge size?

In other words, I am using 3 elements @ 240 v- 18 ohms- 13.34 amps and 3200 watts each. So, I would assume that I would be pulling 40 amps at the elements, is that correct?

Also, I know that the distance you are pulling the amps also affects the gauge wire needed so how do I factor that in?

Thanks..

[nuttyman]

I followed this schematic when I did my oven & it worked great 1st try! however I just noticed your print out of the celcius to fahrenheit conversions on your box & it ithey are wrong!! better check your conversions! anyway thank you so much for posting your set-up to begin with.

[RNMHRD]

I followed this schematic when I did my oven & it worked great 1st try! however I just noticed your print out of the celcius to fahrenheit conversions on your box & it ithey are wrong!! better check your conversions! anyway thank you so much for posting your set-up to begin with.

The temp setting conversion on my box is correct for my oven only..

When i first fired my oven up , i used Two different temp gauges to check oven temps at different settings with the controller. I know the conversion is off , but there dead on with my oven..

[nuttyman]

oh-that makes sense. so the readings your TC give are not accurate?

[GeneNewcomb]

Why the jumper? Perhaps that is why mine is not tripping the SSR. The insructions leave quite a bit to desire.

[kcenicola]

If you number the black dots on the bottom of the thermostat from left to right #1, 2 ,3 etc.

Think of the connection between 2 and 3 as a switch that gets turned on and off when the thermostat tells it to. When the thermostat tells it to switch on, the connection closes and one of the two hot legs is now present at the A1 connection on the contactor via the jumper wire. Now the contactor is getting 240 Volts, (120 at the A1 side and 120 at the A2 side)

[GeneNewcomb]

Well that worked sorta. I had bought an SSR that I thought would match the small voltage and current that the digital listed as an output, 3-34 volts DC. It wooked for about ten seconds before it smoked.
I don't understand why it list an output voltage if you have to jump over 120 volts and that becomes the output of the internal switch.
I guess I need to get a contact block that will take 220V?
Thanks for the help,
Gene