Kiln Failure

Houston, we have a problem! Last night’s glaze fire did not proceed according to plan. When I arrived to check on it a little bit ago, the controller was showing PF - Power Failure. Further examination shows melting on the plug and socket! :scream: I think the planned repair bill may be going up a bit in price. :cry:

I disconnected the cord from the socket and turned off the breaker. I placed a note over the socket and over the breaker indicating both are out of service. There was a hot plastic kind of smell when I opened the breaker box. I don’t know if this is new / related or not since I don’t routinely go sniffing the breaker box.

Suggested to-dos for approval by whomever is allowed to approve them:

  • I think we should have an electrician out to look at the plug, socket, breaker, and wiring to determine if there is an obvious reason for this failure outside the kiln.
  • We need to pop open the controller housing on the kiln to determine if there is an obvious reason inside the kiln. I think we should engage Evans to come and do that for us (the owner has been very helpful and knowledgeable and has shown an interest in our success and working with us).
  • When we’ve got feedback from both of those we can move forward with a repair plan and also determine if we need to consider firing some pieces somewhere else in the interim if it looks like there will be a significant delay (hopefully that’s not the case).

Please let me know how to proceed.



The firing did not progress very far. The temperature inside the kiln was perhaps 80-90 degrees. Glazes look ‘untouched’ and the witness cone hasn’t started moving, just changed color.

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With as many folks as are using the kiln, we need to get it fixed right away. Why don’t you go ahead and give Evans a call to see if they can come out and take a look. In the meantime, whether the problem is due to the kiln or the external wiring, we’ll need an electrician to come and repair the circuit. I can call someone to come out, unless you’d rather choose who it is. Either way is fine. When we did our budget last year, we expected to need repairs done on our equipment, so we’ll just bite the bullet and get it done immediately. I can make time to meet repair folks as long as I have a bit of notice. Let me know if you’d prefer that I found an electrician, but I’ll leave it to you to contact Evans.

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I consider us lucky that this didn’t start a fire. We definitely need to make sure that it is properly repaired and that our alarm system is online.

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Here’s a discussion of some things to consider: http://www.potters.org/subject40917.htm

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Thanks for that, Curt. It may very well be a localized hotspot due to poor contact. Perhaps we should consider removing the plug and wiring directly to a dedicated breaker box/cutoff switch while we have an electrician out. I would definitely be in favor of having a licensed electrician perform the work. I know that there are a lot of folks who are perfectly capable of doing the work, but if we do have a fire at some point down the line, I’d hate to have the insurance company try to deny a claim because we weren’t willing to spend the money for a repair by a licensed and insured electrician.

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I feel like we may have just lost one of our nine lives. Where are we in the count?

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I’ll get in touch with Evan’s tomorrow. I don’t feel comfortable suggesting an electrician to use. Perhaps there’s someone we’ve used before that we can call?

I’ll find someone. I’ll start calling to see who is available in the morning.

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Another post with similar advice: http://community.ceramicartsdaily.org/topic/12725-wiring-for-kiln/

So we’re on the schedule for an electrician to come by ASAP, which means Monday unless they have a cancellation. They will give me a call if they do, otherwise they’ll call me on Monday when they’re 20 minutes away.

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What about replacing both the plug and receptacle with a disconnect switch?

A new plug and receptacle of that size are both expensive and probably would need to be special ordered. Also, a disconnect is easier to operate in an emergency and can be fused for additional protection. You could also put anti-corrosion compound on the contacts easily enough to prevent a similar situation. And finally, if there was a similar failure again, it would be inside of a steel enclosure instead of in the open environment.

I have a 60 amp fused disconnect I’d donate if you want.

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A disconnect is our current plan, and your donation would save us some money. The electrician is supposed to call me on Monday, 20 minutes before they head over. Is there a way you can either drop it off or we can make arrangements for me to pick it up?

Thanks Logan!

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I brought it to the ceramics room and put it on top of the kiln so you won’t miss it. The powder coat is a little faded, but the internal parts are sound and it is new enough to have a safety interlock that prevents you from opening the cover when the circuit is energized. It is complete with a set of 60 amp cartridge fuses already installed.

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Thank you, @Logan!

I have not been back to ceramics in a while. When I am in next I will take a look. Are there any smoke detectors in ceramics?

Is the kiln back up and running?

The electrician was out and got us wired up with the box that Logan kindly donated. We’re back to making things all hot and melty… inside the kiln, not outside. I don’t think there are smoke or heat detectors in the studio itself. There are outside in the metalshop.

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