16 S&C Instruction Sheet 768-550
Installation
Connecting Remote Terminal Unit Hardware
Status Inputs
NOTICE
S&C status inputs are dry contacts and S&C Control
Outputs are wetted with 24 Vdc .
Note: The control output contact must be maintained for
a minimum of one second to ensure switch operation .
STEP 13.
When the RTU is supplied by S&C:
All hard ware
status inputs are prewired to the remote terminal
unit. No additional load should be con nected to
these inputs because they are designed for use with
low-power devices and connecting additional load
may cause damage to components.
When the RTU is supplied by others:
Refer to the
included wiring diagrams for status inputs.
Testing the Remote Terminal Unit
STEP 14.
After configuring the RTU (if furnished), testing
functionality of the communication and control
unit and the auto mated switch (if connected to the
communica tion and control unit via the control
cable) can be accomplished with a personal
com puter and suitable user-supplied protocol test
software.
NOTICE
In some computers, the commu
nication port signal
ground is internally con nected to the chassis ground
to reduce electromagnetic interference (EMI) . If such
a computer is used to test a communication device-
equipped communication and con trol unit, a ground
loop is created that will short-circuit one of the battery
packs .
To avoid short-circuiting the battery pack in the
event your computer has this internal connection,
temporarily disconnect the power connector of the
communication device. After the communication
and control unit has been tested, reconnect the power
connector to the communication device.
Test the remote terminal unit in accordance with
the manufacturer’s standards.
