PowerBoss Nautilus Hi-Dump PB45HDSL, Service Booklet

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VACUUM IMPELLER HYDRAULIC MANIFOLD
The vacuum impeller hydraulic manifold performs the following functions:
Pressure relief
Vacuum impeller on and off
Location and operation of the individual vacuum impeller hydraulic valves:
The solenoids that control vacuum impeller functions receives hydraulic pressure and flow from the
center auxiliary pump which has a displacement of .66 cu. In./rev. and supplies a flow of 6.8 gpm.
Hydraulic fluid that powers the vacuum impeller enters the manifold through PORT P.
PRESSURE RELIEF VALVE RV1 in port 9.2 provides pressure relief. This valve allows a maximum pressure
of 2500 psi.
This valve dumps to tank through port T
SOLENOID VALVE SV1 (Impeller on-off) in port 7.2 is a 2-position 2-way normally-open control valve.
When de-energized this valve allows fluid to by-pass the impeller motor and return to tank.
When energized this solenoid closes the return to tank and directs the pressurized fluid flow to the
vacuum impeller motor inlet through port VF OUT.
The outlet side of the impeller motor goes to port VF IN and back to tank through port T.
DETAILED SYSTEM OPERATION:
Scrub brushes:
The “ALL ON-OFF” rocker switch (green switch)and the “BRUSHES OFF” rocker switch, which is
downstream and in series with the “ALL ON-OFF” switch, always apply electrical power to and remove
power from solenoid valves SV2, SV3, SV4, SV5, and SV6 at the same time.
When both of these switches are closed solenoid valve SV2 (all off) is energized and blocks the fluid flow
to tank.
Solenoid SV3 (main brushes on) is energized directing pressurized fluid to the scrub brush motors. The
brushes begin to rotate.
Solenoid valve SV6 (main brushes up-lock) is energized which un-locks the scrub head from its raised
position and allows fluid flow to and from the piston-end of the scrub head cylinder.
Solenoid SV5 (main brushes down) is energized allowing regulated hydraulic pressure to the rod-end of
the scrub head lift cylinder causing the scrub head to lower.
Proportional reduction valve SV4 (Main brush force) is energized and regulates the hydraulic pressure
applied to the rod-end of the scrub head lift cylinder. This provides the variable brush force against the
floor.
Controlling brush pressure: