MSA General Monitors S4100C - Interconnecting Cable Guidelines; Installation of Sensor

Model S4100C
8
3.4 Interconnecting cable Guidelines
• The Smart Transmitter requires an interconnecting cable with an overall screen
(shield) and armour. Cables to BS5308 Part 2, Type 2 or equivalent are suitable.
• Interconnecting cables should be segregated from power and other “noisy”
cables. Avoid proximity to cables associated with radio transmitters, welders,
switched mode power supplies, inverters, battery chargers, ignition systems,
generators, switch gear, arc lights and other high frequency or high power
switching process equipment. In general, maintain a separation of at least 1m
between instrument and other cables. Greater separation is required where long
parallel cable runs are unavoidable. Avoid running instrument cable trenches
close to lightning conductors earthing pits.
• Complete all cable insulation tests before connecting the cable at either end.
• General Monitors do not recommend the use of cable shoes or crimps on any
junction box or housing wiring terminals. Poor crimping can cause bad
connection when unit experiences temperature variations. We therefore
recommend good practice is to just terminate cable or sensor wires as is,
especially in remote sensor applications.
3.5 Installation of Sensor
General Monitors sensors are machined to a ¾ NPT thread for fixing into the junction
box, through a suitably machined entry. Each sensor requires a suitable O’Ring and
Lock Nut to ensure correct assembly. To assemble the sensor into the junction box
the wires should be placed through the O’Ring, over the ¾ NPT thread until it rests at
the end of the machined thread. The sensor is then placed through the entry of the
junction box and held in place by fitting the ¾ NPT Lock Nut. The sensor should be
tightened sufficiently to ensure a good seal, but not over tightened to damage the
O’Ring. The colour coded wires should then be connected into the corresponding
locations of the connector which is installed and labelled in the junction box. Care
should be taken not to tighten the connection on the insulation of the wires.