Rockwell Automation 8520 9/Series Hardware TAB 5 - Manual (Page 123)

Section 5B
9/440HR CNC/Drive System
5B-49
Jumper Setting Three Phase Power
J27 to J26 (factory setting) Grounded system
J27 to GND3 Ungrounded systems
Figure 5B.37
Three–phase Jumper (Series A and B)
9/440HR System Module
Open cover
J26
J27
GND3
Wire Jumper