TM 5-4930-230-13
Section III. OPERATING UNDER USUAL CONDITIONS.
The instructions in this section are for personnel who operate the tank and pump unit. How the unit is started and
stopped in normal weather conditions is described.
Before you operate.
Always keep in mind the CAUTIONS and WARNINGS.
Filling 600-Gallon (2271 Liter) Tanks.
if tank and pump unit is mounted on any vehicle other than a 5 ton vehicle,
extreme caution must be taken when filling the tanks to avoid exceeding
cross-country payload limits.
a. Be sure that suction hoses connecting tanks to the pump assembly are properly secured. Ground
pumping assembly before starting to fill the 600-gallon (2271 Liter) tanks.
b. Bonding and grounding procedures areas follows:
DEATH or serious injury may result if proper grounding procedures are not
followed prior to operating the equipment.
(1) Bonding is the process that equalizes the charge on two unlike objects such as an aircraft and a
refueling nozzle. it is done in order to prevent arcing, in the presence of flammable vapors, as the two objects
are joined.
(a) Extend the grounding cable from the ground reel assembly so the plug (if present) can be
inserted into the vehicle receptacle. Otherwise, attach one of the grounding dips to a bare metal surface of the
receiving vehicle. Attach the remaining dip to the grounding rod. Bond before the dust cap or gas tank cap is
removed to prevent a spark occurring when fuel vapor is present. Do not disconnect the bond until refueling is
complete and the gas tank cap and nozzle dust cap are replaced.
(2) Grounding of equipment is a means to provide a conductive path into the ground so a static charge
isn’t trapped on the surface of the equipment where it could discharge as a spark.
(a) Insert the grounding rod into the soil to the required depth (refer to table 2-2). Drive the rod
into the soil to reach below the permanent ground moisture level.
(b) If the top of the rod is level with the surrounding surface, scoop out an area around the top to
allow attachment of the ground dips to the rod. Attach the dip from the grounding wheel to the exposed
portion of the grounding rod. The refueler and vehicle are now grounded and the refueling process may begin.
Table 2-2. Required Depths for Ground Rods
Type of Soil
Depth of Ground Rod
Coarse ground, cohesionless sands and gravels
6 feet
Inorganic clay, claying gravels, gravel-sand-
4 feet
clay, claying sands, sandy clay, gravelly clay,
and silty clay
Silty gravel, gravel-sand-silt, silty sand, sand,
3 feet
silt, peat, muck, and swamp soil
(3) Methods of Grounding. There is no quick or easy way to test the adequacy of a ground. The testing
procedures (See FM 10-66 Appendix E) are complex and the equipment is bulky and expensive; therefore,
several levels or methods of grounding and bonding are required to meet the various operational needs of the
Army. The three methods/levels are listed in order of preference.
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