What is the overload setting for a motor with a nameplate rating of 480 Volt - 3-phase, 5 HP, and 4 Amps at a 50°C temperature rise?

To determine the overload setting for a motor based on its nameplate rating, you typically use a factor derived from the motor's full load current (FLC) at its rated voltage and horsepower. For a 5 HP, 480 Volt, 3-phase motor, the full load current can be calculated using standard motor FLC tables or formulas.

For a 5 HP motor at 480 Volts in a 3-phase system, the FLC usually falls around 4 to 4.5 Amps. In this case, since the ambient temperature is specified at a 50°C temperature rise, this impacts the thermal characteristics of the motor. Motors are typically rated for certain conditions, and if the temperature is exceeding standard ratings, it’s crucial to adjust overload settings accordingly to accommodate the heat dissipation characteristics of the motor.

The overload setting is generally determined by taking the full-load current and multiplying it by a factor to account for any thermal ratings. A common criterion is that the overload setting is often set at 125% of full-load current for continuous operation. If the calculated full-load current is 4 Amps, 125% of this value would be 5 Amps, which suggests that the overload setting needs to account for