Circuit status, Operating principle, Fault detection – Rockwell Automation 21G PowerFlex 750 Series Safe Torque Off User Manual
Page 29: Figure 2 - stop category 0 – coast

Rockwell Automation Publication 750-UM002F-EN-P - July 2013
29
Description of Operation
Chapter 4
Example 1 - PowerFlex 750-Series Drives, Frames 1…10 Safe Torque
Off Connection with Coast-to-Stop Action, Dual Channel
Figure 2 - 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) will cause the Safe Torque Off option and 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.
Fault Detection
A single fault detected on the Minotaur safety input circuits will result in the
lock-out of the system at the next operation and will not cause loss of the safety
function.
A1 S21 S11 S52 41 13 23 33
A2 S22 S12 S34 42 14 24 34
Minotaur
MSR127TP
GuardMaster
Trojan
SP+
SE+
Sd
SP–
SE–
Sd
Gate
E-Stop
Latching
Button
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