REED B50HPG, Technical Manual, Page: 28 / 235

OPERATION and MAINTENANCE
Rev 1.2 27 of 80
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AUXILIARY CIRCUIT
The auxiliary circuit has been designed and installed for the purpose of operating the
hydraulic function of the auxiliary equipment on the unit, primarily the agitator. This
function is that of the agitator rotation for mixing the material in the hopper and feeding of
the concrete cylinders.
The flow and pressure requirements for the auxiliary circuit are met by employing the
second stage or section of the same tandem pump used on the s-tube shift circuit. With
the engine running and throttle set to maximum RPM, the flow from the tandem pump is
directed to a single spool directional control valve. This circuit also utilizes a solenoid
valve cartridge or dump valve, designed as a safety valve with the purpose of preventing
flow to the auxiliary circuit as commanded by the emergency stop circuit. At start up, the
normally open cartridge directs the oil flow from the tandem pump to tank, prohibiting
function of the auxiliary circuit. When the emergency stop circuit is reset, an electrical
signal is generated to energize the solenoid, closing the cartridge, and blocking flow
directly back to tank, instead allowing the flow to the single spool directional control valve
for operation. The directional control valve has relief cartridge to protect the system
against excessive pressure
When the valve lever is activated the agitator will rotate in forward direction as hydraulic
fluid is
directed to that side of the motor. Rotation can be reversed by moving lever in other
direction.