Electric leakage of furnace (over-current)

You have to pay attention to the alarm lamp during you use CVD.

• Over-current occurs when the thermocouples are inserted too much and contacted with the electric wire of the electric furnace.

• The alarm warns occurrence of over-current by yellow lamp light and beeping sound (You can not hear it from the main room).

• In that case, you should stop running the furnace immediately. Building staffs will come to investigate our lab room. Please explain them.

• Sometimes, this further causes uncontrollable heating of the furnace. The maximum output power is applied to the furnace and temperature keep increasing even if the output power shown in the controller is 0% or the controller is not Run state but Reset state. In that case, pull out the plug of thyristor (furnace).

Log

• 2009/10/xx

  • Over-current.

• 2011/12/13

  • Over-current.

• 2012/01/xx

  • Over-current several times.

  • The thermocouples were fixed to the furnace by screws.

• 2012/07/19

  • Over-current.

• 2014/09/26

  • Over-current.

  • The thermocouples were fixed to the furnace by compression fitting and protected by insulator and cement.

• 2015/11/24

  • Over-current. Probably not due to the furnace but due to the ribbon heater. Short circuit of the ribbon heater probably occurred when it touched water of the water bath.

• 2019/10/31

  • Over-current. Probably due to loosened thermocouple (left). The left thermocouple was fixed again by compression fitting.

  • 2022/10/15

    • Over-current. It stopped when the thyristors were unplugged. The cause is now under investigation...

• 2023/05/10

  • • Over-current. It has been back to the normal state after stopping to use the furnace.