Rockwell Automation 8520 9/Series Hardware TAB 5 - Manual (Page 61)

Section 5A
9/440 Resolver–based CNC/Drive System
5A-59
Figure 5A.44
Grounded Power Configuration
As shown in Figure 5A.45, the ungrounded power configuration does not
allow for a neutral ground point. If you determine that you have
ungrounded power distribution in your plant, you need to move the
factory–installed jumper to the ungrounded power distribution position to
prevent electrostatic buildup inside the 1394. Refer to the ground jumper
procedures for the system module you need to configure. For detailed
information about 1394 ungrounded power configuration, refer to your
1394 users manual.