To achieve the best results, the following notes should be considered:
1. Low level signal wiring such as that associated with thermocouples, RTDs and current loops
should always be kept separate from power and control output wiring.
2. Signal input wiring should be twisted pairs/triplets etc. The conductors should be stranded
rather than solid in construction. All signal wiring should use ground-shielded wires or be
routed through grounded conduit to minimize the effects of RFI and ESD.
3. Exceptional care should be taken when wiring to relay or solenoid coils, as large transients are
produced when coils (or any other inductive loads like motors or arc welding equipment’s
etc.) are switched. This problem can be eliminated using suitable suppression devices across
the coil. Coil transients can also be transmitted through the air, so the recorder itself should
be mounted as far as possible from power control devices and/or wiring.
4. When line power is poorly regulated and / or subject to voltage surges or transients,
consideration should be given to the use of a line conditioning/transient suppressing line
power regulator. Process control motors, valves, relays and heaters should not be connected
to the same power lines that are used for instrumentation.
5. The connection of the recorder to a proper safety earth ground is essential. Such a connection
not only reduces the possibility of electric shock, but also provides the required return for the
recorder line power filters.
6. All local electrical codes of practice must be followed when installing any instrumentation.
7. If wall or pipe-mounting to NEMA 4X (IP65) hose down standard is required, suitable cable
glands must be used to prevent water ingress.
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