Rockwell Automation 1758-RTU202 DataSite Hardware User Manual - Manual (Page 27)

Publication 1758-UM001D-EN-P - June 2011
Wiring the Controller 27
If the outputs are DC, we recommend that you use an 1N4004 diode for surge
suppression, as shown below. For inductive DC load devices, a diode is
suitable. A 1N4004 diode is acceptable for most applications. A surge
suppressor can also be used. See
Recommended Surge Suppressors on page 28
for recommended suppressors. As shown below, these surge suppression
circuits connect directly across the load device.
Suitable surge suppression methods for inductive AC load devices include a
varistor, an RC network, or an Allen-Bradley surge suppressor, all shown
below. These components must be appropriately rated to suppress the
switching transient characteristic of the particular inductive device. See
Recommended Surge Suppressors on page 28 for recommended suppressors.
+24V DC
IN4004 Diode
Relay Or Solid
State DC Outputs
24V DC common
VAC/DC
Out 0
Out 1
Out 2
Out 3
Out 4
Out 5
Out 6
Out 7
COM
(A surge suppressor
can also be used.)
Surge suppression for inductive AC load devices
Output Device Output device Output device
Varistor RC network
Surge
suppressor