TM 9-4120-405-13&P
4-12. GROUNDING.
WARNING
Do not operate the equipment until it has been properly grounded. Serious injury
or death by electrocution can result from operating this equipment when it is not
grounded.
The trailer-mounted, generator-set powered, air conditioner must be grounded prior to operation. The ground can be, in
order of preference: (1) an underground metallic water system, (2) a driven metal rod, or (3) a buried metal plate (refer to
figure 4-6). If the effectively grounded portion of the buried metallic water pipe is less than 10 feet due to insulated
sections or joints, this preferred grounding method must be supplemented by an additional driven metal rod ground or a
buried metal plate ground. A driven ground rod must have a minimum diameter of 5/8 inch of solid or 3/4 inch of pipe, and
driven to a minimum depth of 8 feet. A buried metal ground plate must have a minimum area of 9 square feet, minimum
thickness of 1/4 inch, and be buried to a minimum depth of 4 feet. The ground lead must be at least No. 6 AWG
(American Wire Gauge) copper wire. If a driven ground rod is used, install and connect it as follows.
a.
Installation.
(1)
Remove ground rod and ground driver/puller from the storage box.
(2)
Connect a ground rod coupler (1) to ground rod section with pointed tip (2).
WARNING
Nuts must be securely connected to ground rod driver/puller. Faulty connections
could result in death or serious injury.
CAUTION
Impact disk must be tightened to end of threads on ground rod driver/puller. Also
lockwasher and nut must be tightened firmly against impact disk. If not tightened
properly, damage to threads and impact disk could result.
(3)
Ensure that impact disk is tightened to end of thread on rod of ground rod driver/puller.
(4)
Ensure that lockwasher and nut are tightened firmly against impact disk.
(5)
Ensure that nut and other end of ground rod driver/puller are tightened to end of threads.
CAUTION
Ground rod driver/puller and ground rod must make firm contact inside ground rod
coupler. If not in firm contact, damage to ground rod, coupler, and driver/puller
could result.
(6)
Connect impact disk end of ground rod driver/puller to ground rod coupler that was installed in step b.
Tighten so that end of ground rod driver/puller makes firm contact with end of ground rod inside coupler.
(7)
Use ground rod driver/puller to drive ground rod into ground. Drive ground rod until coupler is just above
surface.
4-13
