TM 10-5410-228-24
b. STATIC Mode. When A4S8 is in the "ON" position, 24 VDC is supplied from A4CB2 through A4S17-
B contacts 21 and 22, A4K16 contacts A2 and A3, A4K17 contacts A2 and A3, A4S8 closed contacts
10 and 4 to light A4DS12 "STATIC" lamp and the CBPS system operates in the "STATIC" profile
mode. The same 24 VDC is routed to A1SV2 through cables 1A4W6, 1A4A1W1 and 1A4A1W3. A
ground is supplied to opposite side of A1SV2's coil through the same cables. This energizes (opens)
A1SV2 while A1SV1 de-energizes (closes) during static mode operation increasing hydraulic fluid
flow through hydraulic system. With A4S8 in "ON" (STATIC) position, contacts 8 and 1 also close
and 24 VDC from A4CB3 is applied across A4S15 contacts 8 and 5, NBC "OFF", through relay A4K7
closed contacts A2 and A3 and cables 1A4W6, 1A4A1W1 and 1A4A1W3 to A1SV6. A ground is
supplied to opposite side of A1SV6's coil through the same cables. This causes A1SV6 to open
(energize) to reduce NBC fan speed during static Non-NBC mode of operation.
24 VDC from ESS MODE switch A4S17-A pin 11 is applied to rib fan switch A4S13 through relay A4K18
closed contacts D2 and D3 if A4K18 is de-energized. A4K18 is de-energized during static mode of CBPS
operation. A4K18 prevents air beam inflation during mobile mode of operation. If rib air pressure is below
1.5 psi, setting the RIB FAN switch to the ON position, applies 24 VDC through A4PG2 LO-SET switch
closed contacts C and B to light RIB AIR PRESSURE LOW lamp A4DS17 (green). 24 VDC from LO-SET
switch contact B is also routed through A4D1 to energize relay A4K9 and apply 24 VDC to 600 SECOND
DELAY relay A4TD2. Once A4K9 is energized it keeps itself energized through a lock-up circuit consisting
of A4K9 contacts A2 and A1 and A4PG2 HI-SET switch contacts H and J. A4K9 remains energized until
A4PG2 contacts H and J open. 24 VDC is also applied to A1SV8 solenoid in the hydraulic manifold to
reposition A1SV8 allowing hydraulic fluid to be ported through the RIB FAN motor. A4TD2 energizes only
after 600 seconds of continuous RIB FAN operation. Energizing A4TD2 closes its contacts 1 and 4 and lights
RIB FAN EXTENDED OPERATION lamp A4DS31 (red). It also sounds unmutable alarm A4LS2. If the
RIB FAN enters EXTENDED OPERATION there is probably a leak in the air beam system or a malfunction
of the electrical circuits controlling rib fan operation. Temperature sensor A19TS1 senses air temperature in
rib inflation manifold. If rib manifold air temperature rises above 175 F, A19TS1 closes and connects 24
VDC from A4D1 to light RIB AIR OVERTEMP lamp A4DS30 indicator (red) and sound unmutable audible
alarm A4LS2. A4D11 and A4D12 isolate the RIB FAN EXTENDED OPERATION circuit from the RIB AIR
OVERTEMP circuit so either circuit can individually sound A4LS2.
NOTE
Rib air pressure must be less than the lo-set point to activate the rib air fan when switching
A4S13 to "ON". One or more dump caps may be removed and then installed to achieve low
rib air pressure during maintenance functions.
As pressure in the air beams and manifold rises above the 1.5 psi low set point A4PG2 LO-SET switch
changes position. Contact C breaks from B and makes contact with D. This applies 24 VDC to light RIB
AIR PRESSURE NORM lamp A4DS16. It also interrupts the 24 VDC to turn out the RIB AIR PRESSURE
LOW lamp A4DS17. When pressure in the air beams and manifold passes the hi-set point, normally 2.9 psi,
A4PG2 HI-SET changes position. This opens contacts H and J which interrupts the 24 VDC to keep A4K9
and A1SV8 energized. A4K9 and A1SV8 de-energize and the rib fan stops operation. If the RIB FAN switch
A4S13 is left in the "ON" position, the sequence will automatically begin again as soon as the air pressure in
the air beams and manifold drops below the low-set point.
1.15.12 NBC Operation.
CBPS system can be safely used in a contaminated area. Selecting NBC mode and closing all exits and
entrances to the LMS and ABS allows the shelter to over-pressurize. During NBC mode, the NBC fan speed
is increased to achieve over-pressurization.
