Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS - Manual (Page 52)

Installing the Assembly
Chapter 6
6Ć2
Avoiding Backplane Power Supply Overload
For each module you plan to install in the I/O chassis, add up it current
load on the backplane power supply. Be sure that this total current is not
so large as to overload the backplane power supply.
The backplane power supply current load of the servo positioning
assembly is:
1771ĆM3
controller
1771ĆES
expanders
Total
Current
1 1 3.45A
1 2 5.15A
1 3 6.85A
Note that if you add the total current draw of one 1771-M3 controller,
three 1771-ES expanders, and either an I/O adapter or mini-processor
module, the total would exceed 8A. In that case you could not use a
1771-P1 or 1771-P2 power supply because they are rated at 6.5A.
If the total current exceeds 6.5A, you can use Power-Supply Modules (cat.
no. 1771-P3, -P4, -P5) to provide 8A, 11A or 16A. The following table
lists the number of axes you can control with a servo positioning system
in a 1771-A4 I/O chassis, based on power requirements and compatibility
of other components used with the 1771-A4 I/O chassis.
I/O Adapter or MiniĆProcessor Module Cat. No.
Power
Supply
Cat. No. 1771ĆAL 1771ĆAS 1772ĆLS 1772ĆLSP 1771ĆLV
1771ĆP1 1 Axis
1771ĆP2 2 Axes 2 Axes
1771ĆP3 2 Axes 1 Axis
1771ĆP4 3 Axes 3 Axes 3 Axes
1771ĆP4 plus
1771ĆP3 or
a second
1771ĆP4 3 Axes 3 Axes