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Lower Mode Of Operation - Gravity
Down and Float
Actuating the ’Lower’ switch on the hand-held controller
sends a signal to the control circuit board on the plow.
This actuates the coil for the ’B’ valve and (if a down
pressure plow) the ’F’ valve, allowing hydraulic fluid to
flow from the lift cylinder to the reservoir.
Once the ’Lower’ switch has been actuated, the system
will stay in this mode until the ’Raise’ function is actuated
or control is shut off, allowing hydraulic fluid to flow
between the reservoir and the lift cylinder. This allows the
lift cylinder to extend and retract as necessary to follow
ground contours while plowing.
Down Pressure (DP) System
This system operates only when both the ’DP’ switch and
the ’Lower’ switch on the hand-held controller are
actuated.
Actuating the ’DP’ switch actuates the pressure switch,
the ’B’ valve coil, the ’E’ valve coil and, through the
pressure switch, the start solenoid as required. When the
’E’ is actuated and the hydraulic pump operates, hydraulic
fluid is directed to the rod end of the lift cylinder, retracting
the cylinder and forcing the plow down.
The pressure switch in this system senses the pressure of
the fluid in the lift cylinder and closes when the pressure
becomes low, allowing the motor and the pump to pump
fluid into the rod end of the cylinder. When the pressure
reaches the proper level the switch opens, shutting off the
motor and the pump.
The system is protected by a relief valve, which relieves
excess pressure if the plow is forced up, such as by a
bump or obstacle in the roadway. Once any obstacle is
cleared, the plow can return to a lower position, which will
also lower the pressure. If the pressure becomes too low,
the pressure switch will activate the motor and pump as
mentioned above to return pressure to normal levels.
The down pressure system is overridden any time the
plow control is placed in the ’Raise’ mode, but will resume
when placed back in the ’Lower’ position.
Also, note that the ’E’ valve is deactivated anytime an
angle function is activated, but returns to its previous
condition as soon as the angle function is completed.
Angle Left or Right Mode of Operation
Actuating the ’Angle Right’ switch on the hand-held
controller sends a signal to the control circuit board on the
plow. This actuates the start solenoid and the coil for the
’A’ valve, allowing hydraulic fluid under pressure to flow
through the ’A’ valve to the swing cylinder. At the same
time, the hydraulic fluid passing through the ’A’ valve
unseats a check valve in the circuit for the ’D’ valve,
allowing hydraulic fluid to flow from the opposite swing
cylinder through the ’D’ valve and back to the reservoir.
Actuating the ’Angle Left’ switch on the hand-held
controller sends a signal to the control circuit board on the
plow. This actuates the start solenoid and the coil for the
’D’ valve, allowing hydraulic fluid under pressure to flow to
the swing cylinder. This fluid also unseats a check valve
in the circuit for the ’A’ valve, allowing fluid to flow from the
opposite swing cylinder through the ’A’ valve and back to
the reservoir.
The angle circuits are protected by a crossover relief
valve set to relieve pressure on the circuit a 2000 PSI. If
the blade of the plow contacts an obstacle during plowing
operations, the crossover relief valves will allow fluid to
flow out of the swing cylinder on the side encountering the
obstacle, allowing the cylinder to retract and allowing the
blade to adjust its angle to relieve the force from the
outside.
Fuse
A fuse is located near the battery in the primary 12V DC
positive power circuit and is in place to protect the
electrical system against direct shorts. A high amp draw
condition will cause the element in the fuse to interrupt
current flow to the plow. The fuse will need to be replaced
after interruption.
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