Installation
2-8 Manual # 42-02-1P21
General Wiring Guidelines
Basic wiring practices and grounding requirements are discussed in this section.
Proper Grounding Procedures
A proper ground is essential to trouble free operation. Ground is defined as a direct connection
to EARTH GROUND. This type of ground is not always available from the electrical supply
panel.
The electrical conduit is not a sufficient ground for the system. Electrical ground should be
obtained and certified from the electrical contractor. If this is not available, keep the following
in mind when seeking an adequate connection to EARTH GROUND:
1. Building steel is not always earth ground. In most cases, building beams rest on concrete
beam pockets, and the earth connection is inadequate.
2. Sprinkler system water pipe is not
adequate because the sprinkler system is, in most
cases, isolated from a free flowing earth water source.
If either of the two methods above are chosen for ground, and a true electrical ground is later
introduced to the system, a difference in potential can occur between the assumed ground and
the actual earth ground. This may lead to unsafe operating conditions and the possibility of
electrical shock to passengers or personnel.
3. A water pipe is an adequate ground only if the water in the pipe is connected to a contin-
uous city water source.
Wiring Connections for Properly Grounded Systems
1. An uninterrupted ground wire of at least #8 AWG should be run from each car control-
ler cabinet chassis or back plate to earth ground. The connection at the car controller
must be free of paint so the ground connection is made to the bare metal of the enclo-
sure. The car controller should read less than 1-ohm to ground with the power off.
2. Ground straps, or short loops of ground wire, should be run from the controller ground
connection to the primary duct connections.
3. An uninterrupted #8 AWG ground wire should be run from the hoist motor frame to the
controller ground. The ground connection to the hoist motor must be free of paint.
4. An uninterrupted ground wire of minimum #14 AWG should be run from a termination
point on the cab to the controller ground.
5. An uninterrupted ground wire should be run from the cab enclosure to the ground ter-
minal on the cab to protect passengers and personnel from electrical shock.
6. An uninterrupted ground wire should be run from each car operating panel to the
ground terminal on the cab to protect passengers and personnel from electrical shock.
7. An uninterrupted ground wire should be run from the dispatch cabinet chassis or back
plate to earth ground. The connection at the dispatch cabinet must be free of paint so
the ground connection is made to the bare metal of the enclosure.
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