MERLIN LEGENDCommunications System Release 6.1
System Planning
555-661-112
Issue 1
August 1998
Before You Begin
Page 1-4Confirming the Location of the Control Unit
1
Grounding Requirements 1
Proper grounding of the installation site is essential for correct and safe
functioning of the system. Grounding protects the system against:
■ Lightning
■ Power surges
■ Power crosses on outside lines/trunks
■ Electrostatic discharge (ESD)
The telephone company is responsible for providing protection of outside
lines/trunks at the entrance to the site. The protection should consist of:
■ Carbon blocks or gas-discharge tubes connected to an approved ground
■ Adequate bonding of the outside line/trunk protector ground and the
power-company ground
!
CAUTION:
Improper ground can result in equipment failures and service
outages. Verify that the AC power uses an approved ground for its
primary ground and that all voltage-limiting devices are attached to
an approved ground. Approved grounds are as follows:
■
The metal frame of the building
■
A metal water pipe connected to an underground water pipe
that is in direct contact with earth
■
An electrode encased by at least 2 inches (5 cm) of concrete
and located within and near the bottom of a concrete
foundation or footing in direct contact with earth
■
A copper ring that encircles a building and is in direct contact
with earth
For most surge occurrences, the following standard grounding requirements
provide adequate lightning and power surge protection:
■ Properly wired, grounded, and bonded outside line protectors
■ Properly wired and grounded AC outlet
■ Properly grounded single-point ground bar
■ Properly wired connection between single-point ground and power supply
