Heat Treat oven problems

Yeah basically I have decided that if I couldn't get it to work this time calling a electrician. Problynsomething stupid too.
 
If it is running properly and the hum isn't a loud buzz, then it is probably OK.
Humming is normal with current flowing through any resistive load. It is called "60 cycle hum". That is how I can tell my oven is cycling on......I hear the hum. If you listen, you can hear it in a large building like a warehouse when the lights are on and it is quiet.

If it still isn't running you should get someone who is familiar with these things to come over with a good meter and take a look.
 
Well made a call. Turns out a electrician lives 4 houses away. Just going to leave it to the pro. Thank you everyone for trying to walk me through this. I know it wasn't easy. I will update what was wrong when it is fixed.
 
It will be interesting to see whats wrong, I certainly have done a bit of skull scratching over this LOL
 
I'm just lucky he lives just down the road. I'm quite off the beaten path. I will keep you in the loop.
 
Kieran, this won't fix what ails you, but I just wanted to make sure you had heat sinks under your SSRs. I think I see them in the pic but can't tell for sure. If not, the rating of your SSRS is less than 50% of what's claimed. Will run good for a while, then they will fail. Also, like Stacey said, solder or crimp lug those wires to the back of your switch and then make sure that any bare wires are reinsulated.
 
Thank you for your concern. I do have heat sinks in the ssr's. I took it all apart since I have a guy coming over to look at it.
 
Kieran Klein said:
I appreciate your effort on trying to make it work. I feel uncomfortable overloading that ssr.
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Jumping one out isn't going to effect the load on the SSR, so unless you are increasing the current draw that shouldn't overload one, provided they are sized correctly for the load. What jumping one out will do is mean that the coils are always live and not being turned off by the door switch. Or rather they go from being a completed 220 circuit to a open 110. This is not how you should run it, but it shouldn't effect if you are over loading an SSR or not.
 
Ok I got the low down from the electrician. First off I had it wired correctly but a series of events compiled on each other. First he said I had a dead short from my elements to the box I guess it was touching. My bad. Second I only had 12ga wire to the shop which he said was not good enough to handle the load couple that with someone splicing it to a 14ga wire in the house I had no chance. My fix is to get the elements better insulated and get 8-10ga wire up to the shop. Then I should be good to go.
 
The "dead short" concerns me a lot. I can't imagine that the electrician didn't look for the short. I would suspect either the screws where the wires and coils are connected, or the pins holding the coils to the firebrick are touching the case. This needs to be corrected and fully checked before anything is done. DO NOT PLUG THE OVEN IN until you have that solved. My biggest concern is that the oven did not trip the breakers with a short to the case. I thought you had the case grounded? If not, you are lucky you did not get badly shocked or killed.

With your previous diagnostic problems, I worry that you don't have the skills needed to find and fix this. I would have the electrician check the entire oven over when you are ready to try plugging it in again.

As for the shop wiring, he is right that you need bigger wiring to the shop, but that wasn't the trouble with your oven. Be glad he told you this, as running a lot of current through a 14 gauge wire can easily cause a fire. There should be a dedicated circuit from the power panel to the shop wired in 8 gauge. I don't know how far the shop is from the power box, or how much lighting and other equipment are in the shop, but it could even need heavier wiring than 8 gauge.
 
bladsmth said:
The "dead short" concerns me a lot. I can't imagine that the electrician didn't look for the short. I would suspect either the screws where the wires and coils are connected, or the pins holding the coils to the firebrick are touching the case. This needs to be corrected and fully checked before anything is done. DO NOT PLUG THE OVEN IN until you have that solved. My biggest concern is that the oven did not trip the breakers with a short to the case. I thought you had the case grounded? If not, you are lucky you did not get badly shocked or killed.

With your previous diagnostic problems, I worry that you don't have the skills needed to find and fix this. I would have the electrician check the entire oven over when you are ready to try plugging it in again.

As for the shop wiring, he is right that you need bigger wiring to the shop, but that wasn't the trouble with your oven. Be glad he told you this, as running a lot of current through a 14 gauge wire can easily cause a fire. There should be a dedicated circuit from the power panel to the shop wired in 8 gauge. I don't know how far the shop is from the power box, or how much lighting and other equipment are in the shop, but it could even need heavier wiring than 8 gauge.
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I will address some of these issues. I was on my phone posting this so was a pain to put in all the detail.

Anyway we didnt find the dead short at first due to the ssr's not being high enough amps to take the load. So they were stopping the load going to the box. Total load was 25.853 amps through the math. So that was a problem. And also why the breaker never tripped. It never got far enough to power the ssr's. Now when we hooked the elements directly to the 220v to see what the real amps were. That is when the dead short appeared and tripped the breaker. I do have the box grounded though maybe not well enough?

As for upgrading the shop wiring. The box in the house it getting ripped out here soon anyway with a new one and the shop will be upgraded with a 100amp wire with a ground at the shop with 6ga. That way I can use more equipment while actually using the oven. He told me 10ga would max it out and would need 8ga or bigger.
 
The SSRs don't know how much current going through them. You can burn them out with too much current load, but that isn't the situation here. They are merely an ON-OFF switch that is electronically controlled. If the power was getting to the SSRs, and the SSRs were turned ON by the PID, the short would have been the same as it was when you directly connected the power. The breaker would have blown in milliseconds. So, either one or both of the SSRs is wired wrong, is not operating ( defective), or is burned out.
 
Well I'm sure glad you didnt touch the box when it was energized, that would have been a shocking experience LOL

And this thread reminded me of something I seen a while back ;0)



Don't get mad I'm just poking a little fun


 
Its ok I am glad I called someone and hope anyone that has a similar problem will learn from my mistakes. When I get the box insulated from the short upgrade to 40 amp ssr's and update the shop wiring I should be set.
 
Kieran,
I am not sure you understood what I was saying.
The wiring short was clearly a problem, and the shop wiring has to be addressed.....but the problem with the coils not working in your previous testing is something else. If everything was wired and running right, there would have been smoke and a blown breaker when you turned on the PID. If there was not blown breaker ( or smoke) then the SSRs never energized.

I wish it was less than a ten hour round trip to Floyd, or I would come over and take a look.
 
I wish that too. I forgot to mention that we did a continuity test on the elements and all was good there and one of the ssr's was indeed dead.
 
This couldn't come at a better time- I'm just beginning to build mine!
I wish everyone who ever made one of those helpful wiring diagrams for building HT ovens would be sure to include, in big red letters, a reminder to GROUND THE HOUSING.
 
Kieran Klein said:
I will address some of these issues. I was on my phone posting this so was a pain to put in all the detail.

Anyway we didnt find the dead short at first due to the ssr's not being high enough amps to take the load. So they were stopping the load going to the box. Total load was 25.853 amps through the math. So that was a problem. And also why the breaker never tripped. It never got far enough to power the ssr's. Now when we hooked the elements directly to the 220v to see what the real amps were. That is when the dead short appeared and tripped the breaker. I do have the box grounded though maybe not well enough?

As for upgrading the shop wiring. The box in the house it getting ripped out here soon anyway with a new one and the shop will be upgraded with a 100amp wire with a ground at the shop with 6ga. That way I can use more equipment while actually using the oven. He told me 10ga would max it out and would need 8ga or bigger.
Click to expand...

Some of this depends on the format of the wire. 8 Guage wire is rated for 40 amps when in some forms but 55 when in armored cable. So setting up a dedicated 50 amp plug like you would do for a stove or oven would solve this problem.

Also as I understood it SSR's are more likely to fail closed that fail open. So if you over load them they essentially are always on. Be careful.
 
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