Compressor Rated Load Amperage (RLA)

The RLA as stated on a refrigeration compressor represents the “rated load amperage” and not the “running load amperage” of the compressor. 

The actual running load amperage of a compressor has nothing to do with RLA. RLA is a mathematic calculation to meet UL standards.

Compressor manufacturers must run a series of tests to determine the Maximum Continuous Amps before the overload trips. Once that has been determined, UL says divide the MCC by 1.56 to determine the RLA.

Copeland and Carlyle use a different factor. They divide the MCC by 1.44.  Tecumseh does use the 1.56 factor

If the RLA has any value it is to determine at what amperage draw the compressor overload will trip and to determine the fuse/circuit breaker size and the wire size. Trying to determine if a compressor is good or bad using RLA is a mistake, it has nothing to do with the actually running load amperage of a compressor.

Disclaimer:  The information contained in this tech-tip is intended for qualified, and if required, licensed technicians who possess an adequate background in the RHVAC industry.  Attempts made to repair RHVAC equipment may result in serious injury and property damage.  The producers/writers of this tech-tip cannot assume any liability for interpretation of this information, nor can we assume any liability in conjunction with its use.