KNOWLEDGEBASE

Why does the kiln's breaker keep tripping?

  1. Breakers can trip on the kiln for a couple different reasons. What is important to know is, when does it trip?
  2. Does it trip as soon as you turn the toggle switch on?
  3. Does it trip as soon as the relays engage?
  4. Does it trip after the kiln has been on for a while?
  5. Another important thing to know is what happens when the breaker is reset.
  6. Does it not let you reset it at all?
  7. Does it immediately trip again as soon as you re-start the program?
  8. Does it wait a while, like 20 minutes, and then trip again?
  9. Does it trip as soon as you turn the toggle switch on? This means there is a short to ground in the control circuit.
  10. Does it trip as soon as the relays engage? This means the short to ground is somewhere after the relays. Often it can be where the element wire passes through the wall of the kiln. On older kilns there are ceramic bushings on the outside of the hole the element wire passes through to keep the element from touching the stainless steel kiln case. They can come off allowing the element to touch the stainless case.
  11. Does it trip after the kiln has been on for a while? This means there is poor connection between the power wires and the breaker (check the tightness of the wires at the breaker) OR it means the wrong size wire was used, OR it means that the breaker itself is worn out or just no good. There is NEVER a problem with the kiln when the breaker just trips after being on for a while, and when you reset it the kiln can come back on.
  12. Does breaker not let you reset it at all, even when the kiln is completely off? This means there is a short to ground somewhere between the breaker and the line side of the relays OR maybe in the first part of the control circuit.
  13. Does it immediately trip again as soon as you re-start the program? This means there is a short to ground somewhere after the relays, like where the ceramic bushing may have fallen out.
  14. Does it wait a while, like 20 minutes, and then trip again? This means for sure that there is either a poor connection between the wires and breaker OR the wrong size wire used, OR a bad breaker.
  15. To find a short, use the multimeter's continuity tester with the power OFF. When you read from Hot to Ground there should be no continuity. In a circuit where there is a short you will get continuity from Hot to Ground. Isolate parts of the circuit and see if there is still continuity from Hot to Ground. Keep isolating a smaller and smaller area in the circuit until you find where the short is.