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PACMotion VFD AC Variable Speed Drive User Guide
GFK-3111A
“STO” Function Response Time
The total response time is the time from a safety related event occurring to the components (sum of) within
the system responding and becoming safe. (Stop Category 0 in accordance with IEC 60204-1).
• The response time from the “STO” inputs being de-energised to the output of the drive being in a state
that will not produce torque in the motor (“STO” active) is less than 1 ms.
• The response time from the “STO” inputs being de-energised to the “STO” monitoring status changing
state is less than 20 ms.
• The response time from the drive sensing a fault in the STO circuit to the drive displaying the fault on the
display/Digital output showing drive not healthy is less than 20 ms.
“STO” Electrical Installation
WARNING
The “STO” wiring shall be protected from inadvertent short circuits or tampering which could lead to failure
of the “STO” input signal, further guidance is given in the diagrams below. In addition to the wiring guidelines
for the “STO” circuit below, section Figure 26: Recommended Installation for EMC Compliance on page 34
should also be followed. The drive should be wired as illustrated below; the 24 V DC signal source applied to
the “STO” input can be either from the 24 V DC on the drive or from an External 24 V DC power supply.
Figure 28: Recommended “STO” Wiring
- Twisted-Pair
- Shielded cables
1213
1213
Protective Capped Trunking
or equivalent to prevent
STO Cable short circuit to an
external Voltage source
.
1
7
Safety relay
Protective Capped Trunking
or equivalent to prevent
STO Cable short circuit to an
external Voltage source
.
Safety
relay
Protected
shielded cables
0V
+24Vdc
External
Power
Supply
- Twisted-Pair
- Shielded cables
1213
1213
Protective Capped Trunking
or equivalent to prevent
STO Cable short circuit to an
external Voltage source
.
1
7
Safety relay
Protective Capped Trunking
or equivalent to prevent
STO Cable short circuit to an
external Voltage source
.
Safety
relay
Protected
shielded cables
0V
+24Vdc
External
Power
Supply
+24 V DC
Wires should
be protected
against short
circuits as shown
above
NOTE
The maximum cable length from Voltage source to the drive terminals should not exceed 25 mtrs.
Using an External
24 V DC Power Supply
Using the Drives On-board
24 V DC Supply