Rockwell Automation 21G PowerFlex 750 Series Safe Torque Off - Manual (Page 30)

30 Rockwell Automation Publication 750-UM002F-EN-P - July 2013
Chapter 4 Description of Operation
Example 2 - PowerFlex 750-Series Drives, Frames 1…10 Safe Torque
Off Connection with Coast-to-Stop Action, Dual Channel
Figure 3 - Stop Category 0 – Coast
Circuit Status
Circuit shown with guard door closed and system ready for normal drive
operation.
Operating Principle
This is a dual channel system with monitoring of the Safe Torque Off circuit and
drive. Opening the guard door will switch the input circuits (S11-S12 & S21-
S22) to the Minotaur monitoring safety relay unit. The output circuits (13-14 &
23-24) cause the drive Enable circuit to trip and the motor will coast to stop. To
restart the drive, the Minotaur safety relay must first be reset followed by a valid
start command to the drive.
Application Considerations
When the hazard analysis for the overall machine determines the need for
external mechanical brakes or other stopping means, the external means shall be
activated after the removal of power for Stop Category 0.
If the Safe Torque Off option sticks ON, the motor will stop on command due to
the enable input. The system cannot be reset when this fault condition exists.
GuardMaster
Trojan
A1 S21 S11 S52 S12
A2 X1 X2
13 23
14 24
S33
Y2
S34
Y1 X3
37 47 57
38 48 58 X4
S22
Y39 Y40
Minotaur
MSR138DP
SP+
SE+
Sd
SP–
SE–
Sd
Gate
24V DC
Common
External
+24V DC
AC Line
Input Power
Motor
Gate Control
Circuit
Gate Control
Power Supply
Jumpers:
ENABLE Installed
SAFETY Removed
24V DC Common
Start/Stop Common
Start
Stop
+24V DC
PowerFlex
750-Series
Stop
Start External
+24V DC