Honeywell 5701 Operating Instructions Manual page 94

MAN0443.P65 Issue 13 Aug 04
05701-M-5001 A02279
CHAPTER 4 - INSTALLATION INSTRUCTIONS
13.4 4 - 20mA Transmitter Connections
The power provided by the Single Channel Control Card is derived
from the dc input to the System 57 (18V to 32V). Check that the
transmitter to be connected is compatible with the actual supply
voltage used.
The maximum current that may be sourced from the field terminals
of an individual Single Channel Control Card to power a field
device is 500mA, however, the total current sourced from all the
channels should not exceed the maximum backplane load current
of 8A.
Transmitters powered from the Single Channel Control Card require
either three or four wire connections and the sensor documentation
will indicate the 0V and +24V power connections and the positive and
negative loop connections.
At the System 57 end of the field cable the sensor wires should be
connected to the S, 01, NS, 0V or 24V terminals on the Field Interface
or Relay Card that is attached to the required Single Channel Display
Card. The exact terminals used vary depending upon whether three or
four wire topology is used, and the requirement for loop current source
or sink configuration. Link options must also be set correctly on the 4-
20mA Sensor Drive Module (see Section 12.3).
The sensor cable screen should be connected to the system earth at
the Field Interface/Relay Card, using the GROUND terminal, or where
the cable enters the cabinet using a metal cable gland, or by other
suitable means.
CAUTION
4 - 31
5701 Control System