What is the purpose of performing a 'bump test' on a servo motor?

The purpose of performing a 'bump test' on a servo motor is to quickly verify the motor's basic functionality and wiring integrity before more extensive testing or operation. A bump test involves sending a very brief, small current pulse to the servo motor to cause it to move slightly, or 'bump'. This test allows technicians to confirm that the motor is receiving power, that the wiring is correctly connected, and that the motor is not mechanically seized or obstructed. For example, if a servo motor is suspected of being faulty after a wiring repair, a bump test can confirm that the motor is now at least receiving power and responding to commands. If the motor doesn't budge during the bump test, it suggests a problem with the power supply, wiring, or the motor itself. Additionally, the direction of the 'bump' can be checked to verify that the motor is rotating in the expected direction, confirming that the motor phases are correctly wired. This is a safety precaution often performed after maintenance to prevent unexpected or erratic movements during full operation. The bump test is a preliminary diagnostic step, not a comprehensive test of motor performance, but it can quickly identify obvious problems and prevent further damage.