G-Tek Corporation Private Limited
11
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.
Special 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 LmNet 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
LmNet line power filters.
6.
All local electrical codes of practice must be followed when installing any instrumentation.
Check for proper Earthing:
Proper Earthing is necessary for best performance of the LmNet. Follow the steps mentioned below
to check whether the earthing given to the LmNet is proper or not:
▪
Find out the Phase line of connection with the help of “Tester with Neon Lamp.”
When Neon
Lamp glows, it is an indication of the phase line.
▪
Once Phase is found, the other hole which is in line of phase is the Neutral line.
▪
The third hole which is apparently bigger in diameter is the Earthing line.
▪
Now take the voltmeter with appropriate measurement range (normally 750VAC or higher)
and put the probes into PHASE and NEUTRAL line and take reading.
▪
The voltage across PHASE and EARTH, and NEUTRAL and EARTH.
▪
The voltage between Neutral and Earth Should not be more than 6V. If by any chance it is
more than 30V, it is a serious fault on earth line. And must immediately be corrected.
Proper Earthing is essential for safety of the personnel and for the proper functioning of the
equipment.
Note:
If connecting the instrument in the panel, panel and LmNet both should be at the same earthing
potential.
