Medium frequency induction furnace equipment operation and debugging process
Ⅰ:Boot and shutdown process
A:Boot step
1.Turn on the circulating water. Check that each control valve is in the correct open/close position, check that the water pressure meets the pressure requirements, and the power supply cabinet 0.1-0.2Mpa,induction furnace 0.15-0.2Mpa.
2.Pressing the closing button to let breaker work, and keeping this state.
3.Open the control switch,Let the control loop be charged.
4.Put the power potentiometer in the “0” position and turn on the reset switch.
5.Slowly adjust the power potentiometer, start the intermediate frequency power supply, start melting, and adjust the power according to the requirements of the melting.
B:Shutdown step
1.Turn the power adjustment potentiometer to the “0” position
2.The reset switch is rotated to the stop position
3.Close the control switch to the off position
4.Stop breaker work
Ⅱ:Empty furnace debugging limit voltage
In the empty furnace state(Empty induction coil—Do not knotted furnace lining and do not put materials), after starting up according to the normal power-on sequence, slowly turn the power adjust button to observe the DC voltage meter and the MF voltage meter display value.Making the MF voltage / DC voltage between 1.3–1.5.After the power adjust button is rotated to the maximum, the DC voltage is ≥ 500V, 700V ≤ MF voltage ≤ 800V(The best value is 750V).If the MF voltage/DC voltage ratio is <1.3, then adjust W4 button on the main board clockwise , if the MF voltage/DC voltage ratio is >1.5, then adjust the W4 button on the main board counterclockwise.If the power adjust button reaches the maximum, the DC voltage is <500V, then adjust the W2 button on the main board counterclockwise until the DC voltage ≥ 500V, 700V ≤ MF voltage ≤ 800V (preferably 750V).
Ⅲ:Debugging current limit after knotting furnace lining
(Note:The lining knotting and heating oven process is based on the information provided by the lining material manufacturer. This document only show you the debugging sequence.)
After the building the lining, the crucible is filled with 2/3 iron scrap and other charging material.Rotate the power adjust button slowly and observe the indication of the DC current meter so that the indication ≤ rated current (400 kW rated current 800 A, 500 KW rated current 1000 A).Until the power button is rotated to the maximum, if the DC current is > rated current, then rotate W1 button on the main board clockwise, and if the DC current is < rated current, then rotate the W1 button on the main board counterclockwise.
1.The maximum power output starts from 5 to 10 minutes. Observe the displayed values of three meter:DC current, DC voltage, and MF voltage. At this time, the DC voltage is ≥500V, the MF voltage is between 700V—800V, the DC current is within ±5% of the rated current. This indicates that mean the debugging was successful. Continue to observe the 2–3 times melting,if the indications are always normal, then put into normal production use.
2.If the power maximum output exceeds 15 minutes, the DC voltage is always less than 500V, and the DC current is always within ±5% of the rated current,it proves that the amount of input capacitance is too much.It is necessary to remove a part of the capacitor. Generally, removed 0.5pieces of the side of the parallel side and the double-pressure side can meet the requirements.(Note: When the capacitor is removed, the whole equipment should be powered off, pay attention to safe operation).After removing the capacitor, adjust the power supply according to step 1.
Ⅳ:Please pay attention when using for the first time
1.When using at the first time, check the lamp on the main board, if the brightness is the same, and check if the equipment leak water
2.The first furnace should be slowly baked furnace at low power, avoiding wet lining to fire damage to electrical components
