Rockwell Automation Allen-Bradley Guard master 442G-MAB Series - Page 24

24 Rockwell Automation Publication 440G-UM001B-EN-P - May 2016
Chapter 3 Installation and Wiring
Safety in Case of Faults
• The operating voltage UB is reverse polarity protection.
• The safety inputs (FI1A/FI1B) and safety outputs (FO1A/FO1B) are
short circuit-protected.
• A short circuit between FI1A and FI1B or FO1A and FO1B is detected
by the device.
• A short circuit in the cable can be excluded by laying the cable with
protection.
Fuse Protection for Power Supply
The power supply must be provided with fuse protection depending on the
number of devices and current required for the outputs. The following rules
apply:
Maximum current consumption of an individual device
I
max
=I
UB
+ I
UA
+ I
FO1A+FO1B
I
UB
= Device operating current (80 mA)
I
UA
= Load current of monitoring outputs OD, OT, OL, and OI 
(4 x max. 50 mA) + solenoid + switches
I
FO1A+FO1B
= Load current of safety outputs FO1A + FO1B 
(2 x max. 200 mA)
Maximum current consumption of multiple devices connected in series
I
max
=I
FO1A+FO1B
+ n x (I
UB
+ I
UA
)
n = Number of connected devices
Requirements for Connection Cables
Observe the following requirements regarding the connection cables:
ATTENTION: Incorrect connections can result in equipment damage or
malfunction.
Parameter Value Unit
Wire cross-section minimum 0.13 (26 AWG) mm
2
R maximum 60 Ω/km
C maximum 120 nF/km
L maximum 0.65 mH/km