Analysis of Frequently Asked Questions about SCR Power Regulator

A group of electric heaters tripped individually

Cause analysis: over-temperature inside the body, over-temperature of the thyristor, control component and circuit failure.

Troubleshooting: The maintenance interlock trip conditions of a single group of heaters include over-temperature inside the body, over-temperature of the thyristor, control component and circuit failure. When a group of heaters trips, you should quickly find and confirm it to eliminate the fault point, otherwise it will affect the Until the unit is operating normally. In the design of the electrical control circuit, each tripping condition corresponds to a central relay. The tripping condition can be determined through the central relay indicator light. If the indicator light of the central breaker lights up, it means that the corresponding tripping condition has been triggered. When an over-temperature fault occurs inside the body, you should check immediately to verify whether the temperature measuring point and the thermostat are working properly. At the same time, increase the air pressure and flow rate, and wait until the temperature drops to the interlock trip value before putting it into operation. When a thyristor over-temperature occurs, If there is a thermal failure, you should check and replace the cooling fan of the SCR power regulator. Control component and circuit failures are mostly caused by loose fuses, central relays, and connecting wires. Replace the damaged fuses, central relays, and tighten the connecting wires of the circuit.

4 sets of electric heaters tripped together

Cause analysis: operator misoperation, improper adjustment of equipment parameters, heater outlet overtemperature, system interlock maintenance tripping, control components and circuit failures.

Troubleshooting: Operators should control the equipment correctly according to the unit working conditions, check and restore the interlocking parameters of the equipment to not exceed the set values, check and verify the heater outlet temperature measuring point and thermostat, check and replace the central relay.

Load voltage is abnormal

1. Check whether the power supply: control board and load power supply are normal. The control board power supply should be in the same phase as the load power supply.

2. Check the load: whether it is no-load and running with light load. Transformer load: the secondary side cannot be no-load and must be fully loaded.

3. Manual check: If the manual control is normal, it is initially judged that there is no problem with the voltage regulator. Otherwise, connect a dummy load and continue checking.

4. Automatic viewing: When the control input changes by 420mA, the voltage change range of R2 terminal should be 05V.

5. The output voltage can only be adjusted to half of the load power supply: one arm of the thyristor module of the voltage regulator is damaged.