INVT Goodrive350 Series Operation Manual page 414

Goodrive350 IP55 High-ingress Protection Series VFD
Reference standards: IEC 61508-1, IEC 61508-2, IEC 61508-3, IEC 61508-4, IEC 62061, ISO
13849-1, and IEC 61800-5-2.
You can enable the safe torque off (STO) function to prevent unexpected startups when the
main power supply of the drive is not switched off. The STO function switches off the drive
output by turning off the drive signals to prevent unexpected startups of the motor (see the
following figure). After the STO function is enabled, you can perform some-time operations
(such as non-electrical cleaning in the lathe industry) and maintain the non-electrical
components of the device without switching off the drive.
Control
circuit
E.1 STO function logic table
The following table describes the input states and corresponding faults of the STO function.
STO input state
H1 and H2 opened simultaneously
H1 and H2 closed simultaneously
One of H1 and H2 opened, and the
other closed
Appendix E STO function description
+24V
UDC+
PWM+
Drive
circuit
PWM-
The STO function is triggered, and the drive stops running.
Fault code:
40: Safe torque off (STO)
The STOP function is not triggered, and the drive runs
properly.
STL1, STL2, or STL3 fault occurred.
Fault code:
41: Channel H1 exception (STL1)
42: Channel H2 exception (STL2)
43: Exception to both channel H1 and H2 (STL3)
Switch, relay, etc.
H1
H2
COM
U/V/W
Note:
The contacts of the safety switch must be opened
or closed within 250 ms; and the cable that
connects the VFD to the safety switch cannot be
longer than 25 m.
UDC-
Corresponding fault
-396-
STO function description