1.14 GENERAL Continued.
Under full CBPS load conditions, a maximum of 3,412 watts (142 amps) is possible. Since the
system is powered by a 200 amp generator, the remaining 58 amps should be adequate for
ECV systems and battery charging.
(2) External Power. External AC power is normally provided by connecting the 10 kW TQG to LMS
power panel; however, any equivalent or greater 208 Vac, 3-phase external source may be used.
AC input power from 10 kW TQG is applied to CBPS components including AC motor A2M1 in
compartment on passenger side of ECV. The AC motor drives a hydraulic pump P2. Hydraulic
pump P2 pumps hydraulic fluid through selected components of ECU. AC is also applied to
converter 1A4A14 which provides DC operating power for CBPS. Because hydraulic system in
external mode is incapable of providing heat required by the system, AC electric heaters located
in ECU are used to heat CBPS.
b. LMS. During deployment of ABS, LMS crew operates controls and indicators for inflating and
pressurizing ABS and sets environmental temperature within CBPS. LMS crew also monitors alarm
indicators on rear control panel and ensures that air is supplied to ABS.
c. Environmental Control. The ECU components are powered by the hydraulic system. Venting,
heating and cooling equipment housed in ECU is controlled by ESS mode selector switch located on
rear control panel. Outside air is drawn into ECU via NBC fan, directed through dust/water
separator (vortex generator), through a plenum in ECU, to three NBC gas particulate filters.
Filtered air goes into a port where it is mixed with filtered return air from LMS. A recirculating fan
directs air across heating or air conditioning coils for heating or cooling. Air is blown into the soft air
duct of LMS and through cloth duct of ABS. When in cool mode, the air conditioner condenser coil is
cooled by passing air over condenser coil with a condenser fan located on driver's side of ECU.
Also located in the ECU is the rib fan used to inflate air beams. Air generated by rib fan is passed
through a flexible hose in LMS to rib manifold in ABS. The rib manifold connects to each air beam
and contains a check valve and shut-off valve. The check valve automatically stops airflow from air
beam. The shut-off valves can be used to isolate a selected air beam for maintenance purposes. A
small hose from air beam manifold to a fitting on LMS is used for measuring air beam pressure.
d. ABS. The ECV tailgate is lowered and ABS is unrolled, inflated and secured with lines and stakes.
Before the air beams can be inflated, it is necessary to verify that shut-off valves on air beams are
opened and air beam dump caps are properly secured. Under normal conditions, rib fan will be on
when air beam pressure is 1.5 psi or lower and will turn off when pressure reaches 2.9 psi.
For NBC operation, the entire CBPS should be decontaminated. (Refer to FM 3-11.5.) Ambulatory
and TALP entry ways must be kept securely sealed to keep contaminated outer surfaces of ABS from
contaminating interior of ABS or LMS. For protection against contaminants, ABS should not be
inflated lower than 0.5 inches of water, gage (iwg).
Over pressurization (positive pressure) is achieved by supplying a continuous, high volume of
air into CBPS to maintain air pressure that is slightly higher than the outside, ambient air
pressure. This results in a continuous outward flow of air to the atmosphere through vents
and any leaks in ABS, thus preventing entrance of outside contaminants.
Pressure in ABS is measured on NBC shelter pressure gage. It is referenced to atmospheric
pressure by use of a pressure tap mounted on power panel of LMS. A momentary drop in
CBPS pressure may be experienced when door is opened. Airlock (differential) gages located
at entrance of ABS are used to measure pressure in ambulatory and TALP airlocks. To
pressurize ambulatory and TALP airlocks, air must flow through airlocks. This is
accomplished by opening outer and inner door flaps. Opening the flaps also controls over
pressurization within ABS enclosure. A connector on power panel allows for connection of an
external Chemical Agent Monitor (CAM) for monitoring biological contaminants. If
contaminants are detected, the NBC fan will automatically turn on. NBC recirculation filter
fans, provided as on-board components of CBPS, are critical to cleansing air of contaminants
in ABS enclosure when personnel enter or exit ABS and must be connected to receptacle
panel. A hand-held CAM, provided with the system, can be used to measure the amount of
contamination in selected areas of CBPS (e.g., ambulatory or TALP airlocks).