Scroll compressor reverse phase and high discharge temperature protection

A low side scroll compressor is protected from both the potentially damaging effects of improper electrical hookup and the development of high discharge temperatures by apparatus disposed in a passage which communicates between the suction pressure portion and a discharge pressure portion of the compressor. The apparatus operates to permit gas flow from the suction to the discharge pressure portion of the compressor through a protective passage, such as when the compressor runs backwards due to miswiring, so as to avert damage to the scroll members. The apparatus permits the flow of gas from the discharge to the suction pressure portion of the compressor through the passage when the temperature of the discharge gas produced by the compressor exceeds a predetermined temperature indicative of an abnormal compressor operating condition. The resulting gas flow in the latter case causes the compressor motor to de-energize.