Earth Connections; Figure 11: System Earthing - Quin Q-drive Installation & User Manual

Q-Drive Installation Manual
5.4

Earth connections

Earthing is very important in any electrical installation. It is an essential safety measure
to prevent electric shock in case of any failure of the equipment, and is also used for
screening between different units. It provides a ground reference point for all units in
the system. Incorrect earth connection can result in erratic operation due to noise or
earth loops, or may prevent the system from operating at all. These problems can be
avoided by careful arrangement of the earth connections, and by techniques such as
isolation.
Control System
8 8 8 8 8
Q U I N
1 ø
Isolating
Transformer
ø 1
ø 2
ø 3
Neutral
Earth
• The earth connections from the isolation transformer or whatever source of
supply is used should be made using a suitable gauge of wire. The IEE 16th
edition wiring regulations (or appropriate local regulations) should be consulted
to determine an appropriate gauge of wire for the earth bonding straps. All the
earth connections should be connected together at one point, preferably on the
electronics cabinet chassis earth connection.
• Do not tie the earth wires together with any low voltage signal cables, or run
them close together in the same conduit or cable duct.
• All screened cables should have their screens connected directly to earth, not via
the system 0V power supply. This is very important, as otherwise noise and
transients picked up in the screen will pass through the system, instead of being
dissipated directly to earth
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Encoder cable
3 ø
Isolating
Transformer
Figure 11. System earthing
Resolver cable
8
Q-Drive
Copyright © 1996 Quin Systems Ltd.
Issue 1.5
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