Emerson Net Safety SC311, Reference Manual

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Reference Manual Installation
MAN-0091, Revision 8 June 2016
Installation 7
2.6.2 Sensor separation distance
The maximum separation distance between the sensor and the transmitter is limited by the resistance
of the connecting wiring, which is a function of the gauge of the wire being used. It is recommended
that sensor separation must not exceed 2000 feet (610 meters) while using 16AWG (1.31mm
2 ) wire.
Refer to 0 for wire gauges and resistance values.
2.6.3 Installation to transmitter or junction box
The SC311 sensor is supplied with a 3/4” NPT male conduit connection and is intended to be mounted
directly to an available 3/4” NPT conduit entry on a Millennium II Transmitter or remotely using a
certified junction box. There is an available offering of certified junction boxes designed specifically to
work with this sensor. Please contact your local Emerson Process Management representative for
further information.
2.6.4 Sensor wiring
Do not open the transmitter, sensor, or junction box enclosure when in a classified area or when an
explosive atmosphere may be present unless the power to the sensor has been removed.
When connecting cable wires, use a small flathead screwdriver to gently press down and hold the
spring connector open. Insert the appropriate wire into the open connector hole, releasing the
screwdriver to secure the wire. Refer to
Figure 2-5 below.
Figure 2-5 Terminal connection
Connect the sensor wires to the Millennium II Transmitter or junction box as per the appropriate
transmitter or junction box manual. Figure 2-6 outlines the connections to a M21 Millennium II
transmitter.
Table 2-1 outlines the wire colors and their purpose.
Table 2-1 Sensor wire colors and terminal definition
Wire color White Red Blue Black Green
Marking +Vdc Sig A Sig B COM
Function 10.5-32 Vdc
Connection
Communication
signal A
Communication
signal B
Common / supply
ground
Earth ground