TM 10-5410-228-24
Placing the control switches in the position corresponding to the above modes opens solenoid valve SV2 by
applying +24 Vdc to the coils. The principle of operation for the hydraulic system is the same for both
internal power and external power (ECV engine or 10 kW TQG). The principal physical difference is that
25 hp is delivered by the engine and pump belt drive system versus 7.5 hp delivered by the external powered
electric motor. This means that not all functions can be performed when using the limited external power.
To ensure that operation of the NBC system remains intact, all other hydraulic power requirements are
removed from the circuit. This allows the hydraulic fluid to flow through the condenser fan motor, M1C,
bypass the recirculation fan motor, and to flow back to the reservoir.
Valve
SV1
SV2
SV4
SV5
SV6
SV7
SV8
SV9
Energized State
OFF
ON
OFF
OFF
OFF
OFF
OFF
OFF
Position
Closed
Open
Closed
Closed
Closed
Open
Closed
Open
Figure 1-26. Static Mode, External Power, Vent Mode, Full NBC