IDA-201 Unit 19 Motor Controls Flashcards (CRF)

Front

full-load amperage (FLA)

Back

A mathematical calculation used to get Underwriters Laboratories (UL) approval for a motor that was used by compressor manufactured before 1972. FLA value was replaced with a rated-load amperage (RLA) value after 1972. It should not be used to determine the proper refrigerant charge, or to determine if a compressor motor is running properly.

Front

locked-rotor amperage (LRA)

Back

The current an electric motor draws when power is applied to the motor, but its rotor is not yet turning. A rule-of-thumb often used by service technicians is that the LRA is normally five times the rated-load amperage (RLA).

Front

relay

Back

A small electromagnetic device to control a switch, motor, or valve.

Front

contactor

Back

A large version of the relay. It can be repaired or rebuilt and has movable and stationary contacts.

Front

solder pot

Back

A device using a low-melting solder and an overload heater sized for amperage of the motor it is protecting. The solder will melt, opening the circuit when there is an overload. It can be reset.