MIL-HDBK-1027/1B
APPENDIX A (Continued)
SEQUENCE OF OPERATION:
1. SUPPLY POWER TO MOTOR CONTROLLER CONTROL TRANSFORMER. THE WHITE
POWER AVAILABLE LIGHT (IL 1) IS LIT. BOTH SELECTOR SWITCH ONE (SEL 1)
AND SELECTOR SWITCH TWO (SEL 2) ARE IN "NORMAL" POSITION AND BOTH AFFF
CONCENTRATE AND BACK PRESSURE GAGES SHOW NO PRESSURE.
2. IN NORMAL MODE BOTH SEL 1 AND SEL 2 SHOULD BE IN "NORMAL"
POSITION, MASTER SOPV CONNECTS SUPPLY PORT TO PORT #2 WHICH SUPPLIES
PRESSURE TO (2) WATER CONTROL VALVE (PRESSURE TO CLOSE) AND CONNECTS
DRAIN PORT TO PORT #1 WHICH RELIEVES PRESSURE TO (3) AFFF CONCENTRATE
DISCHARGE CONTROL VALVE (RELIEF TO CLOSE). (4) BACK PRESSURE
REGULATING VALVE IS IN FULL RECIRCULATING MODE TO AFFF TANK.
3.
TO START PUMP
A. LOCAL OPERATING MODE: PLACE "NORMAL/LOCAL RUN" SWITCH (SEL 1)
IN THE LOCAL RUN POSITION THE PUMP WILL START AND GREEN MOTOR RUN
LIGHT (IL 2) ON THE CONTROLLER IS LIT.
B. REMOTE OPERATING MODE ( (7) HOSE STATION PUSHBUTTON):
MOMENTARILY PUSH HOSE REEL PUSHBUTTON. THE PUMP WILL START AND GREEN
MOTOR RUN LIGHT (IL 2) ON THE CONTROLLER IS LIT. IN ORDER TO ENERGIZE
SOLENOID #2, MOMENTARILY PRESS THE PUSHBUTTON. THE PURPOSE OF THE
LOCAL MODE IS TO ALLOW THE AFFF PUMPS TO RUN, READY FOR ACTION,
WITHOUT INJECTING FOAM INTO THE WATER MAIN. WHEN THE FOAM REEL
STATIONS ARE READY FOR FOAM, THE TRAINEE PRESSES THE REMOTE
PUSHBUTTON.
4. WHEN PUMP IS RUNNING, THE MOTOR CONTROLLER ENERGIZES SOLENOID #2
OF THE (5) MASTER SOPV, WHICH CONNECTS SUPPLY PORT TO PORT #1 WHICH
SUPPLIES PRESSURE TO (3) AFFF CONCENTRATE CONTROL VALVE WHICH GOES TO
FULL OPEN POSITION AND CONNECTS DRAIN PORT TO PORT #2 WHICH RELIEVES
PRESSURE TO (2) WATER CONTROL VALVE WHICH GOES TO FULL OPEN POSITION.
SOLENOID #2 IS DEENERGIZED AT THE END OF ITS STROKE.
5. THE (4) BACK PRESSURE REGULATING VALVE SHOULD SELF REGULATE SO
THAT THE PRESSURE OF THE AFFF CONCENTRATE IS EQUAL TO THE WATER AT THE
FLOW PROPORTIONER.
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Figure A-21G
AFFF Station
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