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Installing the assembly chapter 6 – Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS User Manual

Page 80

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Installing the Assembly

Chapter 6

6Ć30

Figure 6.17

Shielded Cable Grounding Connections

1771 -ES

Expander

8 to 15V dc

Power Supply

for input

Circuts

(customer

supplied)

27K

Motor

Encoder

Tach

Bulletin 1388

DC Servo

Controller

Drive

Twisted pair

with shield

or conduit

8 AWG wire to

central ground bus

I/O Chassis

Ground Bus

Shielded cables are not

required for these discrete

inputs. However, they can

improve noise immunity.

2

1

3

NOTES:

Belden 8761 or equivalent.
Belden 8723 or equivalent.
Belden 8725 or equivalent.

12304

Drive Disable

+ 15V dc

For DAC

(Customer Supplied)

+ Return-

1

1

1

1

2

3

Connecting AC Power

Figure 6.18 shows ac power connections. Incoming ac connects to the
primary of the bulletin 1388 power transformer. Both the 120V secondary
and the 35.5V secondary connect to the bulletin 1388 dc servo controller
drive.

Incoming ac also connects to the primary of an isolation transformer. The
secondary of the isolation transformer connects to:

the power supply for the input circuits
the power supply for the I/O chassis backplane
the power supply for the analog output circuit

Figure 6.18 shows a grounded ac system; the low side of the isolation
transformer is connected to the central ground bus. Figure 6.18 also