ating times. Consider installation of the tanks
underground if the installation will be longer than
temporary. Locate the tanks as near the shelter
as practicable and be certain that the bottoms of
the tanks are not lower than four feet (120 centi-
meter) from the fuel pump on the installed gener-
ator set. Connect the fuel line from the external
source to the auxiliary fuel valve.
(5) Support. Be certain that the bearing sur-
face used can support the weight of the generator
(6) Foundation. Since the unit is of the porta-
ble type, no foundation should normally be re-
quired. However, position the unit on reasonably
firm, dry ground using planks, timbers, or a suita-
ble gravel base, as available conditions warrant.
Provide for water drainage away from the unit.
(7) Mounting. Position the unit so that it is
situated in a level plane and so that the frame is
supported on its entire bottom surface. If neces-
sary, the frame may be secured to a suitable base.
c. Grounding Procedure.
Do not rely on grounding or safety
devices to prevent accidents. Electrical
circuits and equipment are potentially
hazardous. Personnel should always ex-
ercise caution to prevent injury or pos-
sible death due to electrical shock.
Generator sets shall be grounded in
order to prevent shock due to defective
insulation, or external electrical faults.
Poor grounding can endanger person-
nel, may damage equipment, and can
create interference in communication or
(1) Install one of the following items as a
(a) Drive a ground rod to
(b) Drive a ground pipe,
steel, to a depth of at least 8
underground pipe may be used
a depth of at least
3/4 inch copper or
feet. An existing
in an emergency.
(c) Bury a 1/4 inch thick iron or steel plate,
approximately 18 inch x 18 inch size, with ground
cable attached, to a depth of at least 4 feet.
(d) Bury a 1/16 inch thick aluminum or cop-
per plate approximately 18 inch
x 18 inch size,
with ground cable attached, to a depth of at least
(e) Position a 1/4 inch thick iron or steel
plate, or 1/16 inch thick aluminum or copper plates,
approximately 18 inch x 18 inch size, on the hard
ground or bedrock beneath the trailer stand or
roll the wheel of a trailer or truck until it comes to
rest on top of the grounding plate.
(f) Saturate the area around the grounding
device with water to increase conductivity.
(2) Ground cables should be copper. Braided
cable is the best, but No. 6 AWG gauge (or larger)
copper wire will suffice.
(3) Connect the ground cable from the
grounding device to the generator set frame
ground stud (figs. 11 and 1-3) and tighten the nut
d. Electrical Connections. All internal electrical
connections for proper operation of the generator
sets have been made by the manufacturer. If it
appears that changes have been made in the
wiring, refer the matter to Direct Support (Inter-
(1) Power transmission cables (model MEP-
015A) (AC unit). Use cable with a minimum wire
size of No. 12 AWG. This size will give a voltage
drop of about 1 volt per 25 ft. (750 centimeters) of
cable when the unit is operated at full load. If the
distance to the load is great, increase the wire size
to No. 10 or No. 8 to minimize voltage drop.
(2) Power transmission cables (model MEP-
025A) (DC unit). When the DC unit is used for
battery charging, the battery cables will normally
be both adequately sized and short. However,
other installations may at some time be made.
Use, as a minimum size, cable of No. 4 AWG for
distances up to 25 ft. (750 centimeters). For longer
distances, No. 3, No. 2, or No. 1 AWG sizes should
(3) Power output connections. Turn the load
switch (AC Unit) or circuit breaker (DC Unit) to
the OFF position and connect the power transmis-
sion cables at the load terminals. Refer to figure
When connecting the power cables on
the DC unit, observe the polarity mark-
ings on both the load and the generator
set and make the connections in the
correct relationship (+ to + and to ).
When connecting the AC Unit, the ter-
minal relationship (LI and L2) to the
equipment may be important to some
equipment with which the unit may be
used. When the relationship is impor-
tant, match the terminals to the load (Ll