Soft Brake - Danfoss VLT MCD 600 Operating Manual

VLT® Soft Starter MCD 600
Operating Guide
1 Parameter 2-10 Stop Time
2
Parameter 2-16 Brake Time
Parameter settings:
•
Parameter 2-9 Stop Mode: Set to DC Brake.
•
Parameter 2-10 Stop Time: This is the total braking time (1) and must be set sufficiently longer than the brake time (in parameter
2-16 DC Brake Time) to allow the prebraking stage to reduce motor speed to approximately 70%. If the stop time is too short,
braking will not be successful and the motor will coast to stop.
•
Parameter 2-15 DC Brake Torque: Set as required to slow the load. If set too low, the motor will not stop completely and will coast
to stop after the end of the braking period.
• Parameter 2-16 DC Brake Time: Set this parameter to approximately 1 quarter of the programmed stop time. This sets the time
for the full brake stage (2).

9.9.5 Soft Brake

For applications with high inertia and/or variable load requiring the maximum possible brake power, the soft starter can be config-
ured 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.
1
1/L1 3/L2
2
2/T1 4/T2
K2
M1
Illustration 37: Wiring Example of Soft Braking
Danfoss A/S © 2020.12
5/L3 A7 A8 A9 COM+ DI-A
6/T3
3
23 22 21
4
K2 K1
K1
3 Coast to stop time
A2
5
Operation
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