Dc Brake With External Zero-Speed Sensor; Soft Brake - Danfoss VLT MCD 600 Operating Manual

Operating Guide | VLT® Soft Starter MCD 600

9.9.5 DC Brake with External Zero-speed Sensor

For loads which may vary between braking cycles, install an external zero-speed sensor to ensure that the soft starter ends DC braking
at motor standstill. Using a sensor prevents unnecessary motor heating.
Configure DC brake for the longest braking time required, and also set parameter 7-1 Input A Function to Zero Speed Sensor. When the
motor reaches a standstill, the zero-speed sensor opens the circuit across DI-A, COM+ and the soft starter terminates the stop.

9.9.6 Soft Brake

For applications with high inertia and/or variable load requiring the maximum possible brake power, the soft starter can be configured
for soft braking.
The soft starter uses a changeover relay to control forward run and braking contactors. While braking, the soft starter reverses the
phase sequence to the motor and supplies reduced current, gently slowing the load.
When motor speed approaches 0, the zero-speed sensor (A2) stops the soft starter and opens the braking contactor (K2).
Soft braking can be used with both the primary and secondary motor sets and must be configured separately for each.
Parameter settings:
Parameter 2-9 Stop Mode: Set to Soft Brake.
•
• Parameter 2-17 Brake Current Limit: Set as required to slow the load.
• Parameter 2-18 Soft Brake Delay: Controls the time the soft starter waits after a stop signal is received, before it begins to supply
braking current to the motor. Set to allow time for K1 and K2 to switch.
• Parameter 7-1 Input A Function: Set to Zero Speed Sensor.
• Parameter 8-1 Relay A Function: Set to Soft Brake Relay.
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Operation
AQ262141844215en-000202 / 175R1174