Ss1 Ramp; Ss1 Ramp Slope - Danfoss VLT Safety Option MCB 150 Installation Manual

Installation Guide | VLT® Safety Option MCB 150/151
6 Parameter 42-49 S-ramp Ratio at Decel. End
Illustration 9: SS1 Delay with S-ramp Stop Profile

3.5.4.3 SS1 Ramp

The SS1 Ramp function can only be used when an encoder is connected to the safety option.
This Safe Stop type allows access to the hazard area immediately after motion is detected as stopped rather than waiting until a
specific time has elapsed.
The safety option monitors the following functions
• Braking ramp:
- In the MCT 10 Set-up Software Safe Plug-in, the braking ramp is specified and monitoring is activated. The braking period
depends on the speed of the motor when braking is started. The braking ramp can be monitored via a maximum speed error
specified in the MCT 10 Set-up Software tolerable in parameter 42-45 Delta V.
• Braking ramp in normal operation:
- The drive starts with the configured braking ramp when safety function Safe Stop 1 has been activated. Once the speed is at 0
speed limit, STO is activated.
• Safety function STO is activated when the configured limit value for the position error is exceeded.
A standstill threshold 0 speed (parameter 42-46 Zero Speed) for activating the safety function STO can be specified in MCT 10 Set-up
Software.
Safety function STO is activated when 0 speed is achieved.

3.5.4.4 SS1 Ramp Slope

For the stopping process, the safety option initiates a stop signal to the drive and monitors the controlled braking by monitoring the
braking ramp. The admissible deceleration ramp is specified in parameter 42-44 Deceleration Rate. If the safety option requests a Safe
Stop 1, the drive must decelerate at least with the steepness of this deceleration ramp, even under heavy load. If the drive does not
fulfill the admissible deceleration ramp during a Safe Stop 1 requested by the safety option, an STO is triggered immediately. The
motor then performs an uncontrolled stop. This action prevents the drive from continuing to run or even accelerating if an error
occurs.
Table 4: Parameters for SS1 Ramp Slope
Parameter
Parameter 42-44 Deceleration Rate
Parameter 42-45 Delta V
Parameter 42-46 Zero Speed
Danfoss A/S © 2018.09
N O T I C E
Unit Range
RPM/s 1–30000 RPM/s
RPM 1–10000 RPM
RPM 1–600 RPM
Functions and Systems Overview
Default
1500 RPM/s
120 RPM
10 RPM
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