ALLEN BRADLEY 1747-L551 PLC Processor

3–4
System Installation Recommendations
!
ATTENTION: The 1746 chassis, the enclosure, and
other control devices must be properly grounded. All
applicable codes and ordinances must be observed
when wiring the adapter system.
Ground connections should run from the chassis and power supply
on each adapter and expansion unit to the ground bus. Exact
connections will differ between applications.
Europe: Reference EN 60204 for safety information on grounding.
Also, refer to Allen-Bradley Programmable Controller Grounding
and Wiring Guidelines, Publication Number 1770-4.1.
United States: An authoritative source on grounding requirements
for most installations is the National Electrical Code. Also, refer to
Allen-Bradley Programmable Controller Grounding and Wiring
Guidelines, Publication Number 1770-4.1.
In addition to the grounding required for the adapter and its
enclosure, you must also provide proper grounding for all controlled
devices in your application. Care must be taken to provide each
device with an acceptable grounding path.
This figure shows you how to run ground connections from the
chassis to the ground bus. Two acceptable grounding methods are
shown; we recommend using a ground bus because it reduces the
electrical resistance at the connection.
Earth Ground
(#8 AWG)
wire
5.2 mm 2 (10 AWG)
2 mm 2
(14 AWG)
2 mm 2
(14 AWG)
Note: Keep wire
length as short as
possible.
2 mm 2
(14 AWG)
5.2 mm 2 (10 AWG)
Preferred Grounding Method
Publication 1747-6.2