During the regular inspection of the vector inverter, please cut off the power supply, stop the operation of the vector inverter, and remove the outer cover of the vector inverter. The main inspection is the places that cannot be inspected without stopping the operation or the places where problems are difficult to find in daily inspections, as well as the inspection and adjustment of electrical characteristics.

After the vector inverter is powered off, there is still a high charging voltage on the filter capacitor of the main circuit. It takes a certain amount of time to discharge, usually 5-10 minutes. Before starting the inspection, you must wait for the charging indicator to go out and test with a voltmeter to confirm that the voltage is below the safe value of 25V DC.

1: Check whether the cooling system is normal and clean the dust on the dustproof net.

First, clean the internal parts of the vector inverter. Use a vacuum cleaner to absorb the internal dust. Use a soft cloth to wipe things that cannot be sucked. Since dust and foreign matter may fall during operation, it should be cleaned from top to bottom. The leads of the main circuit components, the insulated terminals and the ends of the capacitors should be carefully wiped with a soft cloth. The cooling fan system and the air duct should be carefully cleaned to keep the inside of the vector inverter clean and the air duct unobstructed.

2: Due to the temperature rise and vibration during the operation of the vector inverter, the terminals and leads of the main circuit components and the control circuit are often loose, resulting in corrosion, oxidation, poor contact and disconnection. Therefore, it is necessary to check whether fasteners such as screws and bolts are loose, and tighten them as necessary. For welded parts and crimped terminals, check for corrosion, discoloration, cracks, breakage, etc. In addition, check whether the frame structure is loose and whether the conductors and wires are damaged.

3: Vector inverter Check whether the connection on the control circuit board is loose, whether the capacitor is leaking, whether the line on the circuit board is rusted or broken, etc. Generally, the actual capacity of the capacitor on the control circuit cannot be measured, and its performance and life can only be inferred based on its surface condition, working condition and surface temperature rise. If there is no abnormality on the surface, it can be judged as normal. Check the resistors, inductors, relays and contactors on the control circuit, mainly to see if there is looseness or broken wires, whether the terminal block is damaged, and whether the contacts are rough.

4: Check whether the filter capacitor is leaking and whether the capacitance is reduced. High-performance vector inverters have the function of automatically indicating the capacity of the filter capacitor. The capacitance and initial value of the capacitor at the factory can be displayed on the panel, and the capacity reduction rate and estimated life of the capacitor can be displayed. If the vector inverter does not have this function, a capacitance meter is needed to measure the capacitance. The measured capacitance should be greater than 85% of the initial capacitance, otherwise it must be replaced. For the surge absorption capacitors and resistors in the surge absorption circuit, check whether they are abnormal, whether the diode limiter, nonlinear resistor, etc. are discolored and deformed.

5: Check whether the insulation resistance is within the normal range. The vector inverter has been tested for insulation when it leaves the factory, and users usually do not perform insulation tests again. However, after a period of operation, when the insulation resistance needs to be measured during maintenance, the following steps should be followed, otherwise the vector inverter may be damaged. Before measuring, all wires of the vector inverter should be removed.