Induction furnace intermediate frequency power cabinet electrical interlock, safety interlock description

1.1 Waterway interlocking. If the IF power supply suddenly loses water, the IF power supply will stop after 8 seconds delay.

1.2 Current and voltage double closed loop system When the voltage or current exceeds the limit value of the protection circuit, the system immediately cuts off the control power.

1.1 Electrical Control Design The self-locking device prevents system failure during misoperation.

1.4 When the plant suddenly loses power and the main power supply suddenly loses power, the standby diesel generator set will automatically start after the delay, and supply power to the water supply pump and hydraulic pump station in the furnace area.

1.5 The central control cabinet is equipped with an emergency stop device, which can be interlocked with the high-voltage vacuum switch at the front end of the transformer. In an emergency, the high-voltage power supply to the furnace area can be cut off immediately.

1.6 Leakage furnace alarm system is to detect the leakage current of the furnace lining. If the leakage current is greater than the upper limit, the centralized control cabinet will emit an audible and visual alarm signal. When the leakage current exceeds the upper limit, the intermediate frequency power supply can be directly turned off.

1.7 When the hydraulic pressure suddenly leaks or the hydraulic pipe suddenly bursts, the furnace body can be locked or slowly lowered by the shut-off valve.

1.8 When the centralized control cabinet detects that the hydraulic pressure is insufficient, the intermediate frequency power supply cannot be started.

1.9 Each branch inspection instrument can monitor the temperature of the main components. If the temperature exceeds the upper limit, the centralized control cabinet will give an audible and visual alarm. If the upper limit is exceeded, and the delay is passed, the intermediate frequency power supply can be cut off.

7.1.10 Console Door The main disconnect switch is not in the "off" position and the console door cannot be opened.

1.11 When the grid voltage is high, the grid voltage is low, the water temperature is high, the water pressure is low, etc., the IF power supply does not stop immediately, but the protection signal is first indicated. If the protection signal still exists after 10 seconds, the shutdown enters the protection state. .

1.12 In the intermediate frequency power cabinet, a sensor for measuring the air temperature is also provided. When the temperature inside the power cabinet exceeds 40 °C, the alarm will automatically stop.