Frequency converter in the work after a period of time, it is necessary to regular maintenance, usually once a year, mainly check whether screws, bolts and plug-ins are loose, conductor corrosion and other problems on the site, so what are the specific maintenance and maintenance work content? 

Dust the inverter regularly, especially the rectifier cabinet, inverter cabinet and control cabinet. If necessary, remove the circuit boards in the rectifier module, inverter module and control cabinet and dust them. Whether the lower air inlet and upper air outlet of the frequency converter accumulate dust or are blocked by too much dust.  Because the heat dissipation of the frequency converter requires a large ventilation volume, the dust on the surface area is very serious after a certain period of operation, and it must be cleaned and dusted regularly. 

Open the inverter at the front door, back door open, carefully check the ac and dc bus without deformation, corrosion and oxidation, bus joint screw is loose, the installation of fixed point of solid screw is loose, fixed with insulation or insulating column with and without cracking or deformation, if any should be replaced in a timely manner, to tighten, the bus has occurred deformation must be adjusted. 

After dusting the circuit board and bus, carry out necessary anti-corrosion treatment, brush insulation paint, and remove the burr of the bus that has partial discharge and arc pulling before processing.  For the insulation board which has been broken down, the damaged part shall be removed, and the insulation board of the corresponding insulation grade shall be used for isolation treatment near the damage, and the insulation shall be tightened and tested and deemed qualified before it can be put into use. 

Whether the operation and rotation of the fans in the rectifier cabinet and inverter cabinet are normal, turn them by hand when stopping the machine, observe whether the bearings are stuck or noisy, and replace the bearings or repair them if necessary. 

Intermediate dc circuit of capacitor with and without leakage, shell expansion, bubbling or deformation, the relief valve is broken, conditional on the capacitance, leakage current and withstand voltage test, does not meet the requirements of the capacitance for replacement, for new or long-term idle unused capacity, change the former must be on the passivation treatment.

Carefully check whether the terminal block is aging or loose, whether there is a short circuit hidden fault, whether the connection line is firmly connected, whether the wire skin is damaged, whether the circuit board plug is firmly connected. Whether the connection of the main power line is reliable, whether the connection is heated and oxidized, and whether the grounding is good.