Drying And Maintenance Methods For Ac Reactors When Insulation Resistance Decreases

During the long-term operation of electrical equipment, the internal insulation system of ac output reactor may be affected by changes in ambient humidity and temperature. When the internal humidity of the equipment increases, the insulation resistance value of the windings and insulation structure will decrease. Operation and maintenance records show that this situation is more common in equipment in humid environments or after long-term shutdown and restart. During maintenance, the drying device is usually inspected, and the condition of the silica gel desiccant is an important basis for judging changes in internal humidity. Silica gel gradually loses its moisture-absorbing capacity after absorbing moisture; once the desiccant is saturated, it needs to be replaced with new desiccant in a timely manner to restore the dry conditions inside the equipment.

Analysis of the Causes of Decreased Insulation Resistance in AC Reactors

If the insulation resistance of ac reactor for inverter equipment in operation decreases, it is often related to internal moisture absorption, changes in sealing performance, or material aging after long-term load operation. Desiccants or breathing devices are usually installed inside the equipment shell to control the moisture content in the air. When the silica gel gradually changes color or becomes saturated with moisture, moisture in the air can easily enter the internal space of the equipment, and a moisture deposit may form on the winding surface, resulting in a significant decrease in the insulation resistance value during measurement. Equipment maintenance personnel usually make a comprehensive judgment based on insulation resistance testing and observation of the desiccant condition during regular inspections.

Silicone Drying Material Replacement and Maintenance

During maintenance of electrical line reactor systems, when a decrease in insulation resistance is detected and an increase in internal humidity is confirmed, the common procedure is to replace the silica gel with a new one. The maintenance steps typically include powering off the equipment, opening the drying unit, removing the moisture-absorbing silica gel filler, refilling with desiccant, and restoring the sealing structure. After the new silica gel is put into use, the internal air humidity of the equipment will gradually decrease, improving the insulation system environment. Insulation resistance data will also be re-measured in the maintenance record to determine the operating status after maintenance.