Rla is rated load amps as applied Fla is full load amps that the motor is capable of Lra is locked rotor amps Fla is not listed on a hermetic compressor, the mfg would have to provide that information if needed. It is an issue on drive and starter selections for commercial and industrial equipment since both fla & rla must be known for selections and setup. Chillers in particular may have ...
RLA= Rated load amps or running loads amps depending on mfg. FLA= Full load amps LRA= Locked rotor amps.
I consider rla to be a maximum load. Therefore I always make sure the compressor is drawing less than rla when operating under NORMAL conditions. That way there is a little leeway for things like dirty condenser coils or high ambient conditions. And a quick rule of thumb is lra ÷6 = rla. That formula isn't exact but it gets you really close.
This one bothers me. Technicians think the compressor RLA is the maximum current it will draw. To see how that isn't true, first we need to found out what the RLA is. RLA is short for Rated Load Amperes, and it is a calculated value based off of the MCC. What's that? MCC stands for Maximum...
RLA is a mathematical calculation required to meet Underwriters Laboratories (UL) approval. The compressor manufacturer must run a series of tests to determine the Maximum Continuous Amps (MCA) before the overload trips.
(RLA IS NOT RUNNING AMPS) as many are reading RLA to be running amps, Copeland and possibly Tecumseh have been removing them from labels because thinking these are running amps can mis-diagnos a compressor. Trouble shooting with RLA has no value. so a formula to get RLA from LRA is useless and doesn't jive with the newer compressors.