Power unit: Undervoltage when opening the brake

What does A30054 mean?

The power supply voltage for the brake has dropped below 21.6V (24V - 10%) when the brake is commanded to open. The alarm value (r2124) indicates the detected voltage. This undervoltage can prevent the brake from opening properly, leading to mechanical binding, potential damage to the brake mechanism, or a failure to start the motor.

• Insufficient 24VDC supply voltage for the brake control circuit, dropping below 21.6V (as read in r2124) during brake opening.
• High resistance or poor connection in the brake power supply cabling, leading to voltage drop under load (e.g., brake coil current draw).
• Overloaded 24VDC power supply, causing sag when the brake coil draws current or other components simultaneously activate.
• Faulty brake coil or wiring that draws excessive current, causing the supply voltage to drop.

Click steps to track your progress.

1. 1

   Measure the actual voltage at the brake coil terminals (e.g., X110/X111) using a multimeter during the brake opening command.

2. 2

   Inspect the wiring connection points for the brake power supply (e.g., terminals 30, 31, 32 on the power unit) for loose connections or corrosion.

3. 3

   Verify the capacity and stability of the external 24VDC power supply unit, checking if other loads are drawing excessive current.

4. 4

   Adjust parameter P0007 if a different brake voltage threshold is required, ensuring it remains within safe operating limits.