Air compressor motor burned Case Analysis - short circuit caused by metal debris

Inclusion winding metal chips are short circuit and ground insulation value is low culprit. Vibration during normal operation of the compressor, as well as every time you start winding by electromagnetic force and twist, will promote inclusion in between the winding and winding enameled metal shavings between the relative movement and friction. Sharp edges will scratch enameled metal shavings insulation, causing a short circuit.

Sources include the construction of metal shavings left behind brass scrap, slag, compressor damage internal wear and spare parts (such as broken valve) is falling metal chips. For full-hermetic compressors (including hermetic scroll compressor), these metal shavings or crushed will fall on the windings. For semi-hermetic compressors, some particles with the gas flow in the system and the lubricating oil, and finally gathered since the magnetic windings; and (produced such bearing wear and motor rotor and stator wear (sweep chamber) when) some metal shavings will directly on the winding. Winding metal shavings gathered after the short circuit occurs just a matter of time.

We need to draw particular attention to the two-stage compressor. In the two-stage compressor, the return air and return to normal oil directly into the first level (low level) cylinder, compressed by the pressure tube into the motor winding cooling chamber, and then, and ordinary single-stage compressor, as the second stage (high-grade cylinder). Back gas with oil, so that the compression process has been skating on thin ice, if we have back to liquid, the first stage of the cylinder valve can easily be broken. Broken valve after the pressure tube can enter the winding. Thus, two-stage compressor motor short circuit occurs due to metal shavings easier than single-stage compressors.

Unfortunately, things are often conspire, compressor problem at boot time news channel analysis is often lubricating oil burning. Badly worn metal surface temperature is very high, and the lubricating oil 175 & ordm; C over at the beginning of coking. System, if there is more moisture (vacuum pits is not ideal, lubricants and refrigerants large water content, air enters negative return pipe rupture, etc.), lubricants may occur acidity. Acidic oil will corrode the brass and the winding insulation, on the one hand, it can cause copper phenomenon; on the other hand, the poor performance of copper atoms containing insulation acidic lubricating oil provided the conditions for the winding short.