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Rockwell Automation Publication 1769-UM021G-EN-P - October 2015
Chapter 7
Use I/O Modules with CompactLogix 5370 L1 Controllers
Embedded Input Points
The embedded input points on the CompactLogix 5370 L1 controllers support
2-wire and 3-wire input devices. You can wire the input devices to be powered in
one of the following methods:
•
By using an
external power supply
, as shown in
- In this case,
you can monitor the input devices even if field power is interrupted, for
example, by the MCR.
This method is required if you must continue reading data from the input
devices when the embedded output terminals are disabled, for example,
when the use of a Master Control Relay (MCR) disrupts output power.
•
By using the
V terminal
on the embedded I/O module, as shown in
- In this case, you cannot monitor the input devices even if field
power is interrupted, for example, by the MCR.
show examples of how to power 2-wire and 3-wire input
devices in your application.
IMPORTANT
, use the following guidelines:
•
With this wiring configuration, you can monitor the input devices even if
field power is interrupted, for example, by the MCR. The FP- connection
must be maintained as a reference for inputs to function.
•
With this wiring configuration, the controller does not help protect field-
side devices from overcurrent draw conditions.
•
Design your application so that power consumption does not exceed the
power supply ratings.
•
The following figure is a wiring example that complies with the National
Electrical Code (NEC) standard for isolation between system and field
power.
•
The FP+ terminal on the removable connector is the voltage connection.
•
The FP- terminal on the removable connector is the common connection.
•
The MCR must be closed for the removable connector to provide power to
the embedded I/O module.
•
Install a user-replaceable fuse with overcurrent protection of 4…6 A @
52.5…68.25 A2t in line between the incoming power and the FP+
terminal.
For series A L1 controllers
only
, you must use a separate, dedicated Class 2
power supply for the CompactLogix 5370 L1 controller and a separate power
supply for the embedded I/O module (see
).
