Analysis of Common Faults in IF Furnace Maintenance

Posted by adela li on February 4th, 2017

1. If debugging buffer speed is not ideal, can be adjusted by W5 to fine-tune, anti-clockwise adjustable buffer time shorter. And vice versa tone buffer longer.
2. Light load operation, such as the emergence of reactor power low-end tremor, is a limiting pressure radical, may be refractory lining appropriate to enlarge the limiting pressure value, or clockwise adjustment W5 until the tremolo elimination.
3. Maintenance in case of over-voltage over-current action at the same time the phenomenon should be handled with refractory raw material caution, must not blindly enlarge the protection value, should focus on checking the following aspects:
1) small angle is too small;
2) commutating inductance ignition;
3) Inverter silicon soft breakdown;
4) Reactor turn-to-turn short circuit;
5) water cable bad contact;
6) main circuit to ground refractory materials for furnace    (including sensors);
7) Inverter triggering loop insulation (such as pulse transformer, intermediate frequency transformer primary and secondary leakage);
4. In the boost line, in a particular case, the isolation capacitor and the IF transformer resonant, there will be irregular over-voltage over-current, temporary short-circuit capacitor can be shorted to verify the (must ensure that the effusion Reactance, or IF frequency transformer will burn soon). If the verification is true, can be Refractory company changed by changing the value of series capacitance (or in the capacitor and then a vibration resistance 500 ~ 5K / 5W) to eliminate the resonance phenomenon.
5. If the phenomenon occurs when feeding over-current, may be appropriate to enlarge the over-current value (generally over-current limit is 1.2 times) can be. Similarly, over-voltage phenomenon can also be handled by the method.
6. Protection action sub-overload protection and fault protection,
Overload protection is caused when the charge changes in the protection action, this protection action, the reactor is not too much impact sound;
Failure protection refers to the inverter subversion, phase loss, undervoltage, component breakdown and other equipment is not refractory material caused by the normal protection action, fault protection reactor shock sound great, must not blindly amplify over-current over-voltage value, otherwise it will increase malfunction.
7. For the equipment running in the phenomenon of burning silicon can be divided into the following circumstances:
A: fixed position burning silicon for several reasons:
1) cooling is not good, can be judged by the test component operating temperature, treatment approach is to clear water or replace the water jacket;
2) pulse transformer primary and secondary insulation breakdown, the kind of reason will usually cause the corresponding power amplifier tube damage;
3) corresponding to the pressure resistance or RC absorption circuit damage or poor contact;
4) side by side silicon poor performance (not normal opening or shutting down), the phenomenon is often overlooked by maintenance personnel, burn a lot of silicon, until the silicon is also burned, changed after the return to normal.
B: no regular burning silicon protection system is generally faulty, should focus on checking the over-voltage, the main circuit contact problems and insulation problems. Of course, inverter fault trigger circuit will cause irregular silicon burning.
8. The device can not be started normally in the following two cases:
1) Equipment failure - the breakdown of the inverter components, water cable open circuit, the sensor inter-turn short circuit, compensation capacitor breakdown, the trigger circuit is not normal and other reasons, for the kind of failure, only repair damaged parts can be restored;
2) The load impedance does not match, heavy load is not good start, by increasing the reactor clearance, reducing the value of commutation inductance, resonant circuit socketed magnetic ring, reactor inverting side and then contact the magnetoresistance (20 / 3KW) , The reactor ends and then bypass resistance (20 / 3KW), change the constant current start value (adjust W10 or W5), increase the center frequency VCO voltage (5 ~ 7V) and other methods to solve, but the best way Is to reduce the compensation capacitor or increase the number of turns inductor to adjust the load impedance.
Small angle problem: As the commutation inductance and inverter output to the presence of compensation capacitor lead inductance, heavy load, the load impedance of the inverter current time increases, the original tune a good small angle will become smaller, this time may rise power to Half of the inverter subversion, so no-load small angle, it should be too large for the better (generally Ua / Ud = 1.2 ~ 1.3)
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