Grounding Requirements - Nortel Meridian 1 Planning And Installation Manual

Page 30 of 590 Chapter 3 — System and site requirements

Grounding requirements

553-3021-209 Standard 1.00
Before you install an Option 11C Mini and before you apply AC power,
measure the impedance of the building ground reference. An ECOS 1023
POW-R-MATE or similar meter is acceptable for this purpose. If the ground
path connected to the Option 11C Mini has an impedance of 5 Ohms or more,
make better grounding arrangements. Make any improvements to the
grounding system before you install the Option 11C Mini.
The following are additional grounding requirements:
Never connect the single point ground conductor from the Option 11C
Mini system to structural steel members or electrical conduit. In
particular, never tie this conductor to a ground source or grounded
electrode that is not hard-wired to the building reference conductor.
• Ground conductors for the Option 11C Mini system:
— must not be smaller than #6 AWG (#40 metric) at any point (see
Table 6 on page 31 for a list of grounding wire requirements specific
to certain regions)
— must be routed through the same conduit as the phase conductors
serving the system
— must not be smaller than any phase conductor in the same conduit
— do not carry current under normal operating conditions
• All ground conductors in the building:
— must be isolated from the neutral bus except at the service entrance
to the building
— must be hardwired to the main ground reference
• Avoid spliced conductors. Continuous conductors have lower impedance
and are more reliable than spliced conductors.
July 1999
CAUTION