The 139-H-FLC is designed to record memory for up to 30 minutes electronically to simulate the heat build-up in the motor.  If an overload does not occur during those 30 minutes then the memory will be refreshed. If however an overload or a motor start-up occurs the circuit remembers those conditions and is able to reduce the time available for future overload conditions. If the motor enters a trip condition due to excessive heating the relay will lock out the restart for at least 30 minutes to allow for motor cooling. Motor start trip conditions and overload conditions are the two that may cause motor heating and therefore have a thirty minute lockout time. Jam-rapid trip, short circuit, unbalance, or ground fault conditions do not cause heating and are able to allow the rotary to perform an immediate system reset.

The user has the ability to choose from up to fifteen different run curves of the 139-H-FLC Multilin General Electric motor protection relay. Four switches are used to select the desired run curve. The user can locate the manufacturer data of the motor to plot data on the run curve for custom adaptation of the 139-H-FLC to the motor in need of protection.