BR data

What does A794 mean?

One or more of the brake resistor data settings (parameters 43.08 … 43.10) are incorrect or missing. This prevents the drive from correctly calculating brake resistor operation and protection. Incorrect data can lead to improper braking or resistor damage.

• Brake resistor nominal resistance (`P43.08` (Brake resistor resistance)) or power (`P43.09` (Brake resistor power)) values are either `0` or outside the valid range.
• Brake chopper activation voltage (`P43.10` (Brake chopper ON voltage)) is set to an illogical or out-of-range value (e.g., below `DC bus undervoltage limit`).
• Typographical error during manual parameter entry via the control panel or PC tool.
• Corrupted parameter memory within the drive causing incorrect default or saved values for brake resistor data.

Click steps to track your progress.

1. 1

   Retrieve the nameplate data from the physically installed brake resistor for its nominal resistance (Ohms) and rated power (Watts).

2. 2

   Enter the correct nominal resistance value into drive parameter `P43.08` (Brake resistor resistance).

3. 3

   Enter the correct rated power value into drive parameter `P43.09` (Brake resistor power).

4. 4

   Verify the brake chopper activation voltage `P43.10` (Brake chopper ON voltage) is set to a reasonable value, typically `700VDC` for a `400V` class drive.

5. 5

   If parameters were previously saved, try reloading a known-good parameter set from a PC tool (e.g., `DriveManager`).