Rockwell Automation Publication 1769-UM021G-EN-P - October 2015
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Connect Power to the Series A L1 CompactLogix 5370 Controllers
Appendix C
6.
Connect the wire that is connected to the 24V DC- terminal on the
external 24V DC power source to the VDC- terminal, that is, the terminal
that is second from the top, on the removable connector.
IMPORTANT
If your application requires a power control device, for example, a
switch or relay, between the external 24V DC power source and the
CompactLogix 5370 L1 controller to control when the controller is
powered, you must install the power control device at the VDC+
terminal on the removable connector.
If you install the power control device at the VDC- terminal, the
CompactLogix 5370 L1 controller can have problems powering up or
powering down properly.