ABB MicroFlex e190 User Manual page 189

Using external 24 V sources:
MicroFlex e190
PWM control
circuit
PWM power
circuit
Drivers
High
U+
V+
W+
Low
U-
V-
W-
Notes:
* The STO function is activated when one or both of the safety circuit contacts open. If the period between
both contacts opening or closing exceeds a predefined value, a fault in the safety circuit or wiring is assumed
and an error is reported.
* The maximum cable length between drive and the safety switch is 30 m (98 ft).
WARNING! The STO function does not disconnect the voltage of the main and
auxiliary circuits from the drive. Therefore maintenance work on electrical parts
of the drive or the motor can only be carried out after isolating the drive system from
the main supply. If the drive was connected to the input power, wait for 5 minutes after
disconnecting the input power.
Safe Torque Off
connections
X4:1
X4:2
X4:3
Common
Integrated
DC+
Power
Module
U
DC-
Appendix: Safe Torque Off (STO) 189
Motor output (U phase shown)
Safety circuit External
(emergency 24 V
stop switch, source.
relay etc.
+24 V
+24 V
+0 V