Common faults and troubleshooting methods of vacuum hot pressing furnace:

1. The high vacuum cannot be pumped but does not leak (refers to the vacuum meter does not move for a long time)

Possible reasons: (1) aging of high vacuum gauge; (2) aging of diffusion pump oil.

Solution: Replace the vacuum gauge; replace the diffusion pump oil.

2. The thermocouple automatically enters and exits out of order, and the alarm light alarms

Possible reasons: (1) The inner and outer limits are out of order. (2) The in and out motor does not rotate.

Solution: Adjust or replace the internal and external limit devices; test whether the motor is broken, if it is broken, replace the motor of the same model. (Note) Before heating the electric furnace, observe whether the inner limit indicator light is on, and it should be on.

3. The low vacuum cannot be pumped but does not leak (refers to the vacuum meter does not move for a long time)

Possible reasons: (1) The working current of the low vacuum gauge is incorrect; (2) The mechanical pump oil is aging.

Solution: Adjust the working current of the vacuum gauge; replace the mechanical pump oil.

4. The over-temperature warning light is on and alarms

Possible reasons: (1) The furnace temperature is over-temperature; (2) The instrument setting is wrong.

Solution: reset the over-temperature alarm parameters according to the manual

5. The temperature does not rise after a period of use

Possible cause: The heater resistance value becomes larger.

Solution: Increase the output power of the instrument according to the instrument manual; severe aging can only be replaced with a new heater

6. The over-current indicator on the panel of the control cabinet is on and alarms

Possible cause: the heater has a short circuit

Solution: Open the furnace cover to observe whether the heater has a short circuit and troubleshoot.

7. The water cut indicator light is on and alarms

Possible reasons: (1) did not open the water valve; (2) the water pressure is too low.

Solution: Open the water valve; increase the water pressure.