Common faults and troubleshooting methods for customized high vacuum brazing electric furnaces
10-13-2025 Author: KJ technology
The possible vacuum degree abnormalities and other common faults and troubleshooting methods that may occur during the operation of customized high vacuum brazing electric furnaces are as follows:
1. Abnormal vacuum degree
Unable to reach the maximum vacuum degree or decrease in vacuum degree
Possible reasons:
The aging, damage, or improper installation of sealing components can lead to furnace leakage.
Vacuum pump malfunction, such as low pumping efficiency, oil contamination, and shaft seal wear.
There are air leakage points in the vacuum system, such as poorly sealed valves and loose pipeline connections.
Release gas from materials inside the furnace, such as the inner wall of the furnace shell, insulation materials, and the surface of the heat exchanger, after adsorbing gas.
Vacuum gauge malfunction, such as damage to resistance gauge and ionization gauge.
Exclusion method:
Check and replace aging and damaged seals to ensure proper installation.
Inspect or replace the vacuum pump to eliminate issues such as oil contamination and wear.
Perform leak detection on the vacuum system, identify the leak points and repair them, such as replacing valve seals, tightening pipeline connections, etc.
Bake the materials inside the furnace to remove adsorbed gases.
Replace the gauge of the vacuum gauge.
Unstable vacuum degree
Possible reasons:
The working status of the vacuum pump is abnormal.
The operation of Roots pump and diffusion pump is poor.
There are small air leakage points in the vacuum system.
Exclusion method:
Check the working status of the vacuum pump to ensure its normal operation.
Check the operation of Roots pumps and diffusion pumps, and replace or repair them in a timely manner.
Use a leak detector to conduct a comprehensive leak detection of the vacuum system, identify and repair small air leakage points.
2. Abnormal temperature control
The temperature cannot be stabilized at the set value, fluctuates greatly, or the displayed temperature does not match the actual temperature
Possible reasons:
Thermocouple wire breakage, damage, or incorrect installation position.
Temperature control instrument malfunction.
Heating element aging, damage or insufficient power.
Exclusion method:
Replace the thermocouple with a new one and ensure that its installation position is accurate.
Perform maintenance or replacement according to the temperature control instrument manual.
Check the heating element, such as whether the graphite heating tube is contaminated and whether the resistance value has increased. If there is a problem, replace it in a timely manner and ensure that the resistance of the new heating element matches the voltage regulator.
Slow heating, heating power not reaching rated value or unable to heat up
Possible reasons:
Magnetic regulator malfunction.
The heating element is short circuited or open circuited.
The power supply voltage is unstable or lacks phase.
Exclusion method:
Inspect the magnetic voltage regulator and check for loose wiring and normal contacts.
Check the resistance value of the heating element and replace the short circuited or open circuited heating element.
Use a voltage regulator to stabilize the power supply voltage and check for any phase loss issues in the electrical circuit.
3. Mechanical transmission failure
The transmission components are not flexible in operation and have abnormal noise
Possible reasons:
Gear wear and poor lubrication.
Motor malfunction.
Loose coupling or different shafts.
Exclusion method:
Replace worn gears and add lubricating oil to improve lubrication.
Repair the motor to ensure its normal operation.
Tighten the coupling and adjust its coaxiality.
Limit failure or inability to reach the predetermined position
Possible reasons:
The limit switch is damaged or improperly adjusted.
Transmission components are stuck.
Exclusion method:
Replace the damaged limit switch and adjust its position.
Check the transmission components and remove any obstructions.
4. Other common faults
Poor flow of cooling water
Possible reasons:
The water pump and pipeline are blocked.
The water tank and pipes are blocked.
Exclusion method:
Check if the water pump and pipeline are unobstructed and conduct timely maintenance.
Check if the water tank and pipes are blocked and clean them in a timely manner.
The surface of the processed parts is not shiny
Possible reasons:
The cooling gas is impure.
The vacuum degree is too low.
Exclusion method:
Ensure that the purity of nitrogen (argon) gas is above 99.9996%, with a water and oxygen content of less than 5ppm.
Check the vacuum system and cooling system of the vacuum brazing furnace to increase the vacuum degree.
