Cutler-Hammer D320 PLC, Руководство пользователя

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Chapter 4: Installation and Wiring
31
Fastening the Connector
•
Push the expansion cable connector onto the backplane connector firmly until it clicks into
place. (See the following diagram.)
•
To remove the expansion cable from the backplane, release the locking device by pressing the
spring on the expansion cable connector.
Power Supply Wiring
Power wiring
•
For the 120/240 VAC power supply, the power conversion terminal must be shorted for 110
to 120 VAC, and left open for 220 to 240 VAC.
CAUTION:
Connecting 220 V to power supply with the power conversion terminal
shorted (120 VAC mode) will damage the PLC equipment and generate
excessive heat.
•
When connecting the power cable:
To reduce power loss in the wiring, use at least 14 AWG (2 mm) cable.
To reduce the effect of noise, use twisted, shielded cable.
•
An isolation transformer can be used to further reduce noise and to prevent failures from
power problems such as ground faults.
•
Use the same power source for both base and expansion backplane power supplies.
Grounding
•
In normal low-noise environments such as closed-room control cabinets, it is possible to
operate the PLC without frame grounding. However, it is necessary to ground the PLC for
noisy environments, and is recommended for all installations regardless of electronic noise
levels.
•
For the frame ground, use a cable of at least 14 AWG (2 mm) in size. The ground should be
exclusive to the PLC. Sharing the ground connection with other devices can cause problems
due to ground loops and current feedback.
Connector
Spring