Consider this: the compressor moves close to 1,000 pounds of refrigerant an hour when operating at a 50ºF evaporator saturation temperature. At a 45º saturation evaporator, it is near 800 pounds of refrigerant. The metering device moves the same amount of refrigerant in a liquid form that the compressor moves in a superheated form. Think of the work that takes place to move that much liquid and vapor gas. The compressor must receive a low pressure cold superheated gas at around 60º and move each molecule to a high pressure superheated gas to near 190º. Therefore, keeping the oil clean and void of moisture is a must. Allowing the compressor to operate in as little time as possible in the in-rush amperage mode is very important.
I recommend a start kit to accomplish a short start-up period. All of the high efficiency compressors that have expansion valve metering devices use start kits. The compressor must overcome the pressure difference at start up when the expansion valve is a positive shut-off valve. In my opinion, the start kit is an aftermarket item that should be offered to every client. The life of the compressor depends on it. I recommend a three-wire hard start kit the HVAC technician can carry, since he typically services most makes of air conditioning compressors.