Nortel Meridian 1 option 11C Planning And Installation Manual page 43

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Note: A separately grounded cabinet is grounded the same as a
single-cabinet system.
Conductive conduit linking panels and equipment are legal for use as a
grounding network in most countries. It is recommended that properly sized,
insulated copper conductors routed inside conduit for all Option 11C system
ground paths be used whenever possible. A ground link dependent on conduit
may compromise or defeat the improvements made by installing dedicated
panels and transformers. Here are the reasons why:
• Conduit links may be separated by personnel servicing unrelated
equipment. If such a separation occurs anywhere between the
Option 11C system and the building ground reference, the conduit is
incapable of providing a ground path. This is a hazardous situation.
• Metallic conduit is liable to corrode over time, particularly at threaded
connections. Such corrosion will increase resistance significantly. This
problem is compounded when multiple links are involved.
Application(s) of paint over the conduit may accelerate the corrosion
process.
• Conduit is required to be anchored to secure surfaces. Often, it is bolted
to structural steel members, which may function as ground conductors to
very noisy equipment, such as compressors, motors, and so on. The
coupling of these noisy signals into the Option 11C grounding system
may seriously impair its performance. The resulting intermittent
malfunctions can be difficult to trace.
The Option 11C system is available in both AC-powered and DC-powered
versions.
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The AC-powered version is presented in two separate sections in this
Chapter:
• Optimal AC-powered installation
• Alternative AC-powered installation
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