Grounding 19" Rack-Mounted Baseplates; Programmer Grounding - GE 90-30 PLC Series Installation And Hardware Manual

All baseplates grouped together in a Series 90-30 PLC system must have a common ground
connection. This is especially important for baseplates that are not mounted in the same control
cabinet.

Grounding 19" Rack-Mounted Baseplates

There are two Adapter Brackets used for mounting a 10-slot Series 90-30 baseplate to a 19" Rack.
Regardless of which of the two Adapter Brackets is used, the 19" Rack should be grounded as per
the instructions in "System Grounding Procedures," including Figure 2-10. (For details on the
Adapter Brackets, see the "Mounting a Baseplate to a 19" Rack" section earlier in this chapter.)
Nineteen-Inch Rack-mounted PLC baseplates should be grounded according to the guidelines in
the "Baseplate Safety Grounding" section, using a separate ground wire from the PLC baseplate as
shown in the previous figure (Fig. 2-11).

Programmer Grounding

For proper operation, the computer (programmer) running the PLC software must have a ground
connection in common with the CPU baseplate. Normally, this common ground connection is
provided by ensuring that the programmer's power cord is connected to the same power source
(with the same ground reference point) as the baseplate. If it is not possible to ensure this common
ground scheme, use a port isolator (IC690ACC903) between the programmer and PLC serial
connection. If the programmer ground is at a different potential than the PLC ground, a shock
hazard could exist. Also, damage to the ports or converter (if used) could occur when the
programmer serial cable is connected between the two.
GFK-0356Q Chapter 2 Installation
If using the Recessed Mount Adapter Bracket (IC693ACC313), the ground wire can be
installed as shown in Figure 2-11 with the ground attached to the Recessed Mount Adapter
Bracket. An additional ground wire connecting the Adapter Bracket to a solid chassis ground
on the 19" Rack should be installed. Use the same or equivalent hardware and paint removal
scheme as shown in Figure 2-11.
If using the Surface Mount Adapter Bracket (IC693ACC308), the ground wire should be
run from the baseplate as shown in Figure 2-11, to a solid chassis ground on the 19" Rack.
Use the same or equivalent hardware and paint removal scheme as shown in Figure 2-11.
Failure to follow programmer grounding recommendations could result in
personal injury, equipment damage, or both.
Warning
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2-13