Two important inspections before induction melting furnace commissioning
Cooling water circuit inspection must be carried out before induction melting furnace commissioning
Check whether the cooling water is in and out of all parts, cooling water pipes, branches, components
Is there any leakage or water seepage at the joint, and it is obstructed to observe whether the plastic water pipe is folded or bent.
The waterway is smooth. The waterway connection of the intermediate frequency power supply should be connected in series according to the same potential principle, especially
When the water quality is not ideal. A water circuit connection system in series with the potential. If individual branches must be connected in series with different potentials, the branch cooling water plastic tube should have a length of 1.2m or more. Leakage or condensation of the thyristor can cause malfunctions and must be eliminated in time. The specified water pressure of each waterway must be adjusted according to the product specifications.
Induction melting furnace phase sequence inspection before shape inspection
(Thyristor, copper busbar, each reactor, transformer, IF capacitor bank, furnace switch, induction heating coil, water-cooled cable, etc.) are accurate, then phase sequence
an examination. The medium frequency electric furnace power frequency three-phase incoming line must be connected according to the phase sequence specified in the device specification. If the phase sequence is reversed, the rectification trigger pulse timing will be disordered and the equipment cannot operate normally. After replacing the power transformer or the induction melting furnace device in the workshop, the additional power supply site must be replaced.
Recheck the phase sequence. The test phase sequence can be performed by means of a phase sequence meter or an electronic oscilloscope. When using an oscilloscope, connect a 1:1 isolation transformer between the oscilloscope and the oscilloscope's power supply. When this condition is not available, the temporary method is to remove the grounding wire in the oscilloscope power cord plug. At this point, note that the oscilloscope case is live during use and must be insulated from the ground; at the same time, the human body cannot touch the oscilloscope case. When used, the oscilloscope's trigger selection is placed in “Power Trigger”. When using a dual trace oscilloscope, be aware that the ground of the two y-axis input probes must be at the same potential, or only one probe ground wire should be used, and the other probe ground wire should not be used. At the same time, the unused ground wire should be properly handled to avoid contact with other circuits or the ground. When measuring the strong electric phase sequence, the oscilloscope probe ground wire is connected to the intermediate frequency electric furnace cabinet shell, and the test head is connected to any phase of the power frequency grid to see the phase voltage waveform. It is checked that the A phase of the power grid is connected to the A phase of the induction melting furnace device, and the B and C phases can be treated in the same manner. If the phase sequence of the power grid does not match the phase sequence of the intermediate frequency electric furnace, it can be connected at any two of the three phases of the power frequency incoming line.
