
MERLIN LEGEND Communications System Release 6.1 | Issue 1 |
Installation | August 1998 |
Installing the Control Unit | Page |
AC Power and Grounding | |
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WARNING:!
An improper ground can cause equipment failures, service outages, and electrical shock. Verify that the AC power uses an approved ground for its primary ground, that all
Approved Grounds
Approved grounds are listed below, in order of preference:
■Building Steel. The most preferred ground.
■Acceptable Water Pipe. Must be a metal, not plastic or vinyl,
underground water pipe at least ½ in. (1.27 cm) in diameter, and in direct contact with the earth for at least 10 ft. (3 m).
It must be electrically continuous so that the protector ground is uninterrupted. (Check for insulated joints, plastic pipe, and plastic water meters that might interrupt electrical continuity.)
A metallic underground water pipe must be supplemented by the metal frame of the building, a
—Other local metal underground systems or structures, such as tanks and piping systems, but not gas pipes
—Rod and pipe electrodes, a
—Plate electrode, a minimum of 2 square ft. (61 square cm) of metallic surface exposed to the exterior soil
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