Rockwell Automation T3464 ICS Regent AC Guarded Digital Output Module - Manual (Page 9)

(T3464) AC Guarded Digital Output Module
P D - 6 0 2 1 M a r - 0 6
9
current flows through the neutral wire, so it is important to
size both the line and neutral wiring to enable them to handle
this fault current.
Modules report a open load fault when an output is
commanded on and no user load is connected. All output
circuits in service must have load connections for proper
diagnostic operation. Unused outputs can be left unconnected
so long as they are never commanded to be on. These modules
do not test for load faults when an output circuit is
commanded off.
Blown fuse detection is independent of user load connection or
output circuit on/off state. However; when operating in a fault
tolerant configuration, the module will report an “OC” (open
circuit) fault instead of a “BF” (blown fuse) fault if both
outputs are on and only one of the two outputs has a blown
fuse.
The module should not be used in applications where a one-
time 200 millisecond load bump (turn-on) cannot be tolerated.
Fail-Safe Configuration
As shown in Figure 3, the fail-safe configuration uses a single
Guarded module. In this configuration, the worst case failure
will cause the output to fail to the off state.
In a fail-safe configuration, removing the module disables all
outputs.
Figure 3. Fail-Safe Configuration.