About Locked Rotor Amps Calculator (Formula)
A Locked Rotor Amps (LRA) Calculator is a useful tool for assessing the electrical characteristics of electric motors when they start up and experience a locked rotor condition, meaning the rotor is prevented from turning. LRA is a critical parameter for motor selection and circuit design to ensure safe and reliable operation. Here’s an overview of the formula used in a Locked Rotor Amps Calculator:
Locked Rotor Amps (LRA) = Voltage (V) / Impedance (Z)
Where:
- Locked Rotor Amps (LRA) is the current drawn by the motor during startup under locked rotor conditions, measured in amperes (A).
- Voltage (V) is the supply voltage provided to the motor, measured in volts (V).
- Impedance (Z) is the total impedance of the motor and the connected circuit at startup, typically expressed in ohms (Ω).
Calculating LRA is crucial for ensuring that the electrical system, including circuit breakers and fuses, can handle the initial surge in current when a motor starts. It helps prevent electrical overload, equipment damage, and potential safety hazards during motor startup. Electricians, engineers, and maintenance professionals often use this calculator to determine the appropriate circuit protection and power supply for motors in various applications.