Inspection method for electrical faults of induction melting furnace
(1) The dangers of electrical equipment must always be fully recognized.
(2) In situations where there are dangerous mixed voltages (DC and AC), such as measuring in coils, DC power supplies, and leak detector systems, you must be especially cautious.
(3) Special attention should be paid to unexpected voltages that may appear in faulty equipment. An open circuit of the discharging resistor may cause dangerous charges to remain on the capacitor. Therefore, you should “turn off” the power supply and discharge all capacitors before removing the bad capacitor, connecting the test equipment or removing the power supply circuit to be tested.
(4) Confirm all voltage sources and current paths before measuring wiring, ensure that the equipment is well grounded and the fuse of the correct value type is installed intact (see the relevant regulations of the national electrical standard), and set the appropriate measurement range before turning on the power.
(5) Before testing with an ohmmeter, open and lock the circuit and ensure that all capacitors are discharged in the cut-off state.
(6) After verifying the phase sequence of the power supply, the electrical components such as the electric switch can be correctly wired. The electric switch can only be operated after the frequency conversion main machine is powered off. It is strictly forbidden to approach or operate the switch when the variable frequency power supply cabinet is energized.