Conduit Requirements - Meridian Nortel 1 Option 11C Mini Installation Manual

Page 54 of 332 Chapter 3 — System and site requirements

Conduit requirements

553-3021-209 Standard 3.00
Chassis powered by different service panels
For each Main Chassis, connect a #6 AWG (#40 Metric Wire Gauge) ground
wire from the chassis to the NTBK80 grounding block. See Table 10 on
page 49 for grounding wire requirements specific to some areas. If any
chassis cannot be powered from the same service panel, ground it separately
from the other chassis back to the service panel that supplies it. Power each
Main Chassis and Chassis Expander pair from the same service panel.
Note 3: If a chassis requires a separate ground, ground it using the same
method that you use for a system with one chassis.
Note 4: In the UK, you can connect the grounding wire from the chassis
to an NTBK80 grounding block or through a Krone Test Jack Frame.
Grounding multiple pieces of equipment in a rack/cabinet
You must ground each piece of equipment in a rack/cabinet. If a piece of
equipment does not have a ground lug, then ground the whole rack/cabinet.
Conductive conduit linking panels and equipment are legal for use as a
grounding network in most countries. For all system ground paths for the
Option 11C Mini, use the correct size of insulated copper conductors routed
inside conduit when possible. A ground link that depends on conduit can
defeat the improvements made by installing dedicated panels and
transformers. The following are the reasons why:
• Personnel who service different equipment can separate conduit links. If
this separation occurs between the Option 11C Mini system and the
building ground reference, the conduit cannot provide a ground path.
This situation is a hazardous.
• Metal conduit often corrodes, especially at threaded connections.
Corrosion increases resistance. This problem becomes worse when
multiple links are involved. If you apply paint over the conduit, it is
possible that the corrosion process will occur more quickly.
• Always fasten conduit to secure surfaces. Often, conduit is bolted to
structural steel members, which can function as ground conductors to
noisy equipment (for example, compressors and motors). The coupling
of these noisy signals into the Option 11C Mini grounding system can
damage its performance. The resulting intermittent malfunctions can be
difficult to trace.
April 2000