Innotech Omni C14, Installation Instructions Manual

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Page 33
Omni Installation Instructions
© Mass Electronics Pty Ltd 2017 Chapter 3 – Electrical Installation
Cabling plays an important role in the installation of Omni system. The following general
cabling guidelines should be observed:
In all cases, use electromagnetic-shielded cable for sensor wiring:
• When necessary to protect cabling from physical damage, both shielding and physical protection
may be provided by running the cable in a metal conduit. Alternatively, use steel wire armoured
(SWA) cable, which also contains an electromagnetic shield
• Avoid running cables in the vicinity of high voltage power cables or cables carrying switching
voltages/currents. This especially applies to sensor signal cables
• Power supply and digital outputs cables must have multi-strand conductors with a cross-sectional
area of 1mm² for each conductor
• The earth cable to an Omni System enclosure must be a minimum of 2.5mm², and wired in
accordance with local electrical regulations
• For UIOs, a minimum 16 conductor (0.5mm²) cable is strongly recommended.
• For communications, a minimum 16 conductor (0.5mm²) shielded cable is required.
Table 3-1 provides assistance in determining the cabling requirements for various installation
configurations. It shows the dimensions, wire gauge designations and resistance values per
unit length for common wire sizes. Use this table to determine specific cabling requirements for
your installation.
Conductor Area (mm²) Diameter (mm)
Nearest SWG or
BWG
Nearest
AWG
Ohms per 100
metres
0.5 0.80 21 20 3.44
1.0 1.13 18 17 1.72
1.5 1.38 17 15 1.15
2.0 1.60 16 14 0.86
2.5 1.78 15 13 0.69
Table 3-1:
Nominal Resistance for Wire Sizes at 20°C
• SWG = Standard Wire Gauge, BWG = British Wire Gauge, AWG = American Wire Gauge.
• All SWG, BWG and AWG numbers are for the largest wire if a direct equivalent to the mm² wire size is not available.