Danfoss VLT Safety Option MCB 150 User Manual

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A Actual frequency
1 Activation of SS1 Ramp Time
3 Parameter 42-47 Ramp Time
5 Parameter 42-46 Zero Speed
7 Activation of failure function STO
B SS1 ramp
2 Activation of STO
4 Parameter 42-45 Delta V
6 Safety function monitors
Illustration 11: SS1 Ramp Time
3.5.5 Safely Limited Speed
NOTICE
The Safely Limited Speed function can only be used when an encoder is connected to the safety option.
This function is used to limit a machine speed. The main goal is to monitor the motor speed and to adjust the speed to a setpoint.
There are 2 types of Safely Limited Speed:
• SLS without ramp: Monitors the motor speed and, depending on the setting of parameter 42-52 Fail Safe Reaction, trips in Safe
Torque Off or Safe Stop 1 if an overspeed occurs.
• SLS with ramp: Limits the motor speed to a setpoint and, depending on the setting of parameter 42-52 Fail Safe Reaction, trips in
STO or Safe Stop 1, if an overspeed occurs.
The Safe Limited Speed is given as speed limit in parameter 42-51 Speed Limit. The value for the cut-off speed partly depends on the
motor that is being used. A suggested value from the MCT 10 Set-up Software calculates a value for which Danfoss guarantees
functionality. This value is called delta speed limit and is added to the selected speed limit and suggested as value in parameter 42-50
Cut Off Speed.
Functions and Systems Overview
Installation Guide | VLT® Safety Option MCB 150/151
AQ279747441421en-000101 / 130R0292 | 27
Danfoss A/S © 2018.09

Danfoss VLT Safety Option MCB 150 Specifications

General

Brand	Danfoss
Model	VLT Safety Option MCB 150
Category	Control Unit
Language	English