Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 426)

Section 7C
Power Distribution and Wiring Guidelines
7C-8
For a three-phase ac inductive load, connect noise suppressors across the
individual phases as shown in Figure 7C.9.
Figure 7C.9
Three-phase AC Inductive Load
3-phase AC inductive load
C R
C R
C R
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For a small DC inductive load, such as a miniature relay operated by a
switch, connect the diode as shown in Figure 7C.10. The diode must have
a peak voltage rating higher than two times that of the applied voltage.
Figure 7C.10
Small DC Inductive Load
Diode
Load
Small DC inductive load voltage
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Devices used for surge protection should be connected as close to the load
device as possible. When Allen-Bradley relays, contactors, and motor
starters are used, refer to Table 7C.A.