Regular dust removal check whether the fan air inlet is blocked, and clean the air filter cooling air duct and internal dust every month.
Regular inspection should be carried out once a year: check whether the screws, bolts and plug-ins are loose, whether the grounding and phase-to-phase resistance of the input and output reactors are short-circuited, and should be greater than several tens of megaohms. Whether the conductor and the insulator are corroded, if necessary, wipe it with alcohol in time. Measure Switching Power Supply Output the smoothness of each circuit voltage, such as : 5V, 12V, 15V, 24V and other voltages. Whether the contact of the contactor has a fire mark, it is necessary to replace the new contactor of the same model or larger than the original capacity; confirm the correctness of the control voltage, perform the sequence protection action test; confirm that the protection display circuit is not abnormal; confirm that the inverter is The balance of the output voltage when operating alone.
Carefully do the daily maintenance and repair of the inverter, the main contents include:
(1) Regularly dedusting the inverter, focusing on the rectifier cabinet, the inverter cabinet and the control cabinet. If necessary, the rectifier module, the inverter module and the circuit board in the control cabinet can be removed for dust removal. Whether the air inlet and upper air outlet of the inverter are dusty or blocked due to excessive dust accumulation. The frequency converter has a large amount of ventilation due to its own heat dissipation. Therefore, after a certain period of operation, the surface area dust is very serious and must be cleaned regularly.
(2) Open the front door of the inverter, disassemble the rear door, carefully check whether the AC and DC busbars are deformed, corroded, oxidized, whether the screws at the joints of the busbars are loose, and whether the screws at the fixed points are loose or not. Whether the insulating sheet or the insulating column for fixing has aging cracking or deformation, if it should be replaced in time, re-tighten, and the busbar that has been deformed must be corrected and reinstalled.
(3) After dust removal of circuit boards and busbars, carry out the necessary anti-corrosion treatment, apply insulating varnish, and remove the burrs from the busbars where partial discharge and arcing have occurred before processing. For insulation boards that have been insulated and penetrated, the damaged parts shall be removed, and the insulation boards of the corresponding insulation grade shall be insulated in the vicinity of their damage, and the insulation shall be tightened and tested and deemed to be qualified before being put into use.
(4) Whether the fan running and rotating in the rectifier cabinet and the inverter cabinet are normal. When the machine is stopped, turn it by hand to observe whether the bearing has stuck or noise, and replace the bearing or repair if necessary.
(5) Thoroughly inspect the input, rectification and inverter, and DC input fast-melting, and find that the burning is replaced in time.
(6) capacitor in the intermediate DC loop Whether the casing is inflated, bubbling or deformed, and whether the safety valve is broken, conditional can be Capacitance capacity, leak current Test withstand voltage, replace the capacitor that does not meet the requirements, and passivate the new capacitor or capacitor that has not been used for a long time. The usage period of the filter capacitor is generally 5 years. If the usage time is more than 5 years, the capacitance capacity, leakage current, and withstand voltage are obviously deviated from the detection standard, and should be replaced partially or completely as appropriate.
(7) diode, GTO for rectification and inverter Conduct electrical testing with multimeter to determine forward and reverse The resistance value, and carefully record in the form prepared in advance, to see if the resistance between the poles is normal, the consistency of the same type of device is good, and replace if necessary.
(8) Check the main contactor and other auxiliary contactors in the A1 and A2 incoming cabinets, and carefully observe whether the contactors of the contactors have arcing, burrs or surface oxidation, unevenness, and find such problems. The corresponding moving and static contacts are replaced to ensure that the contact is safe and reliable.
(9) Carefully check whether the terminal block is aging or loose, whether there is a hidden fault in the short circuit, whether the connection of each cable is firm, whether the wire is damaged or not, and whether the plugs of each circuit board are firmly connected. Whether the connection to and from the main power line is reliable, whether there is heat generation and oxidation at the connection, and whether the grounding is good.
(10) Whether the reactor has abnormal squeaking, vibration or odor.