Rockwell Automation Publication 440R-UM014D-EN-P - December 2019
17
Power, Ground, and Wire
Chapter 3
• Example 1: A 5-amp load through each of the three output circuits.
5
2
+ 5
2
+ 5
2
= 75 A
From the derating curve, the maximum permitted ambient temperature
is 40 °C (104 °F).
• Example 2: A 2-amp load through each of the three output circuits.
2
2
+ 2
2
+ 2
2
= 12 A
From the derating curve, the maximum permitted ambient temperature
is 60 °C (140 °F).
Surge Suppressors
Because of the potentially high current surges that occur when switching
inductive load devices, such as motor starters and solenoids, the use of surge
suppression is required. Adding a suppression device prolongs the life of the
relay outputs and reduces the effects of voltage transients and electrical noise
from radiating into adjacent systems.
Since this is a safety-related system, the surge suppression device must
connected across the load device. The surge suppression device must not be
connected across the MSR55P relay contacts.
shows examples of output contactors with a suppression device. We
recommend that you locate the suppression device as close as possible to the
load device.
For outputs that use 24V DC, we recommend 1N4001 (50V reverse voltage)
to 1N4007 (1000V reverse voltage) diodes for surge suppression for the OSSD
safety outputs, as shown in
. The diode must be connected as close as
possible to the load coil.
For outputs that use 120V AC or 240V AC, we recommend metal oxide
varistors.
Some devices, like the Bulletin 100S-C
xx
EJ and 100S-C
xx
QJ safety
contactors have built-in suppression, therefore additional suppression devices
are not needed.
Содержание Allen-Bradley Guardmaster 440R-S35011
Страница 12: ...12 Rockwell Automation Publication 440R UM014D EN P December 2019 Chapter 2 Installation Notes...
Страница 40: ...40 Rockwell Automation Publication 440R UM014D EN P December 2019 Chapter 8 Troubleshooting Notes...
Страница 46: ...46 Rockwell Automation Publication 440R UM014D EN P December 2019 Appendix B Regulatory Approval Notes...
Страница 49: ......