Beijer Electronics BFI-P2 V1.21 - Manual (Page 25)

User Guide Revision 1.121
www.beijerelectronics.com
25
4.10.7. “STO“Electrical Installation
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 4.1.1 “Recommended installation for EMC compliance. should also be
followed.
The drive should be wired as illustrated below; the 24Vdc signal source applied to the “STO” input can be either from the 24Vdc on the drive or
from an External 24Vdc power supply.
4.10.7.1. Recommended “STO” wiring
Using an External 24Vdc Power Supply. Using the drives on‐board 24Vdc supply
‐ Twisted‐Pair
‐ Shielded cables
1213
0V
+24Vdc
Safety relay
Protective Capped Trunking
or equivalent to prevent
STO Cable short circuit to an
external Voltage source.
External
Power
Supply
Note : The Maximum cable length from Voltage source to the drive terminals should not exceed 25 mtrs.
4.10.8. External Power supply Specification.
Voltage Rating (Nominal) 24Vdc
STO Logic High 18‐30Vdc (Safe torque off in standby)
Current Consumption (Maximum) 100mA
4.10.9. Safety Relay Specification.
The safety relay should be chosen so that at minimum it meets the safety standards in which the drive meets.
Standard Requirements SIL2 or PLd SC3 or better (With Forcibly guided Contacts)
Number of Output Contacts 2 independent
Switching Voltage Rating 30Vdc
Switching Current 100mA
Wires should be
protected
against short
circuits as
shown above