TM 1-1520-238-T-7
10–108
Change 2
10–18. FUEL CROSSFEED/BOOST SYSTEM – WIRING INTERCONNECT DIAGRAM (cont)
10–18
1-2,4-5
CLOSED
NORMAL
TO
28 VDC
CROSSFEED/SHUTOFF VALVE, AS SELECTED.
2-3,5-6
CPG - FROM AFT: PILOT AFT TK
2-3,4-5
CPG - FROM FWD: PILOT FWD TK
NORM (CPG AND PILOT)
TERMINALS CONNECTED
PROVIDES 28 VDC TO NORMAL OR CLOSED CIRCUITS OF ASSOCIATED
SELECTS FUEL TANK (CELL) TO SUPPLY FUEL TO ENGINES.
ENABLES AND DISABLES PILOT AND CPG FUEL PANELS.
OFF
ON
POSITION
SWITCH
3.
SWITCH POSITION
2.
1.
NOTES:
4.
USED ONLY FOR STARTING ENGINES AND HIGH
ALTITUDE FLIGHT. (HOLDING COIL HOLDS SWITCH
AT BOOST POSITION IF AFT TANK IS SELECTED BY S1).
5.
S2 AND S3 (NORMALLY CLOSED) PROVIDES 28 VDC
TO S5 AND S6 ON PILOT FUEL PANEL FOR NORMAL
OPERATION. (WHEN EITHER CPG FIRE HANDLE IS
PULLED THE 28 VDC IS ROUTED THROUGH ASSOCIATED
PILOT FIRE HANDLE (NOT SHOWN) AND S5 AND S6
OF PILOT FUEL PANEL TO CLOSE SELECTED ENGINE
FUEL CROSSFEED/SHUTOFF VALVE).
6.
PROVIDES 28 VDC THRU S5 AND S6 ON PILOT FUEL
PANEL TO CLOSED TERMINAL OF SELECTED ENGINE
FUEL CROSSFEED/SHUTOFF VALVE, WHEN EITHER OF PILOT OR
CPG FIRE HANDLES ARE PULLED, S2 AND S3 (NORMALLY OPEN).
7.
PROVIDES 28 VDC TO BOOST PUMP AIR VALVE (L15) DURING EITHER
ENGINE START OR WHEN BOOST PUMP SWITCH IS ON.
8
CLOSES WITH BOOST PUMP PRESSURE TO APPLY 28 VDC TO LIGHT
BOOST PMP ON INDICATOR.
9.
ELECTRICAL SYSTEM (TM 1-1520-238-T-6).
10.
M DESIGNATES A SOFT SPLICE WHICH MAY BE DISCONNECTED
FOR A WIRING CHECK.
11.
REFER TO PARAGRAPH 10 - 49. FUEL QUANTITY INDICATION /
TRANSFER - WIRING INTERCONNECT DIAGRAM.
12.
DELETED
13.
POWER PLANTS (TM 1-1520-238-T-4).
14.
UTILITY SYSTEM (TM 1-1520-238-T-8).
15.
AUXILIARY POWER UNIT (TM 1-1520-238-T-8).
HIGHWAY USE: THE ALPHA CHARACTER IDENTIFIES A SPECIFIC LINE, AND THE NUMBER IN
PARENTHESIS IDENTIFIES THE SHEET NUMBER WHERE THE SIGNAL TERMINATES.
M70-002-6A
SHEET 6 OF 6
