Robotics in Manufacturing
SRVO-251

SRVO-251: DB relay abnormal

The dynamic-brake relay inside the servo amplifier - the relay that shorts the motor windings to brake the axis electrically when servos drop - tested abnormal.

What it means

The dynamic-brake relay inside the servo amplifier - the relay that shorts the motor windings to brake the axis electrically when servos drop - tested abnormal. No ladder: amplifier replacement.

Common causes

Ranked by what technicians most often find, most likely first.

  1. Failed DB relay in the servo amplifier.

How to fix it

  1. Replace the servo amplifier with the controller de-energized and locked out, then power-cycle to clear.
  2. Until it is replaced, treat the axis's stopping behavior as suspect. The dynamic brake is part of how the robot stops when power drops.