Rockwell Automation 1771-OW16/B Electro Mechanical Relay Contact Output Module - Manual (Page 6)

Publication 1771-IN069B-EN-P - November 2005
6 Electromechanical Relay Contact Output Module
Load Characteristics
Inductive or high current loads cause arcing of the relay contacts, resulting in
shortened contact life. Use a resistor-capacitor network (RC) across the
contacts to suppress arcing. Failure to use an RC filter network could result in
generation of electromagnetic noise (EMI) which can disrupt nearby electrical
equipment, including your 1771 I/O chassis. Connect the RC filter across the
contacts at the field wiring arm connections. If this is not possible, an alternate
(but not as effective) solution would be to place the RC network across the
load.
Allen-Bradley Suppressors
Calculate Power
Requirements The module receives its power through the 1771 I/O chassis backplane from
the chassis power supply. This supply also provides the necessary power to
energize the coils of the module’s relays. The maximum current required from
this supply with all coils energized is 1.3 A.
Add this current to the requirements of all other modules in the I/O chassis to
prevent overloading the chassis backplane and/or backplane power supply.
ATTENTION
Wirewound resistors do have some inductance associated
with them and may require an RC Filter network.
Allen-Bradley Equipment Suppressor Catalog Number
Motor Starter Bulletin 509 599-KD4
Motor Starter Bulletin 709
1401-N10 1
Relay Bulletin 700 Type N or P 700N5/700N9
Miscellaneous
700-N24
2
1
For starters with 120V ac coils.
2
Bulletin 700-N24 is a universal surge suppressor. You can use it on electromagnetic devices with the limitation of
35 sealed VA, 150V.