Figure 1-17. Static Mode, Internal Power, Heat Mode, Full NBC

TM 10-5410-228-24

1.16 HYDRAULIC SYSTEM Continued.

1.16.9 Static Mode, Internal Power, Heat Mode, Full NBC.

Placing the control switches in the positions corresponding to the above modes opens solenoid valves SV2

and SV5 and closes solenoid valves SV7, SV9, and valve PD1 by applying +24 Vdc to the coils. All remaining

solenoids remain in their normal de-energized positions. The engine driven pump, through a combination of

gravity and suction, draws fluid from the hydraulic reservoir in the ECU and supplies pressure to the

hydraulic control manifold. Fluid flows through the vent (NBC) fan, M3. The fluid is returned to the

manifold where it is divided by flow control, FP3. Part of the fluid is supplied to the recirculation fan, M2,

and the balance is diverted around the motor in order to maintain proper speed control. With solenoid valve

SV5 open and solenoid valve SV7 closed, the fluid is blocked from returning to the reservoir. This forces the

fluid over the heating system relief valve, RD2. The hydraulic fluid pressure at this point is approximately

2,600 psi. As the fluid passes over the relief valve (from the high pressure side to the low pressure side) heat

is generated in the fluid. The hot fluid then flows through the heating coil, HX-1A, where air flowing across

the coils picks up heat from the hot hydraulic fluid to warm the interior of the CBPS. After the fluid passes

through the heating coil, HX-1A, it is routed to the oil cooler, HX-2, filter, F1, and reservoir.

SV1

SV2

SV4

SV5

SV6

SV7

SV8

SV9

Valve

Energized State

OFF

Position

Closed

Open

Closed

Open

Closed

Figure 1-17. Static Mode, Internal Power, Heat Mode, Full NBC