Toro 41188, Service Manual

Page: 177 / 353

Multi Pro 1750 Page 6 − 3 Spray System
Spray System Operation
The Multi Pro 1750 spray system uses a six (6) dia-
phragm positive displacement pump to move spray
solution from the spray tank to the boom nozzles. The
spray pump is self−priming and has a dry crankcase.
The pump is engine driven by a synchronous drive belt
and is engaged with an electric clutch.
The downward stroke of the spray pump’s connecting
rods and diaphragms create suction to allow fluid to be
drawn from the spray tank to the pump through the suc-
tion tube, suction strainer, hoses and connectors. Suc-
tion valves positioned in the pump valve chamber
prevent fluid from being pumped back into the suction
line when the connecting rods change direction. Leaks
in the suction line will cause system problems and often
will be indicated by erratic suction line jumping, erratic
pressure gauge reading and pump noise.
Once to the spray pump, the fluid is pushed by the up-
ward stroke of the pump’s connecting rods and dia-
phragms to the pressure side of the spray system
through hoses, connectors, control valves and spray
nozzles. Pressure valves positioned in the pump head
prevent fluid from being drawn back into the pump. Max-
imum pressure in the system is limited by a pressure re-
lief valve located at the rear of the sprayer. A pressure
gauge on the operator control console indicates spray
system pressure.
The machine operator controls the spray system on the
Multi Pro 1750 with electrical switches located on the
spray console. Switches include a spray pump ON/OFF
switch, an application rate switch, an agitation control
switch, a master boom switch, three (3) individual boom
control switches and two (2) boom lift switches. These
switches control the agitation valve motor, the regulating
(rate control) valve motor, the master valve motor, three
(3) boom valve motors and the hydraulic boom lift sole-
noid coils.
When the spray pump is on, the application rate (in-
crease/decrease) switch allows the operator to adjust
electrical current to the regulating (rate control) valve
motor located behind the spray tank. Higher current res-
ults in a pressure rate increase and lower current results
in a pressure rate decrease. Desired spray pump pres-
sure should be based on boom nozzle selection and in-
tended sprayer ground speed. See the Nozzle Selection
Guide (Toro Form No. 3351−389) for information re-
garding boom nozzle selection.
When the spray pump is engaged and the agitation con-
trol switch is ON, the agitation valve motor located be-
hind the spray tank is opened. This open valve directs
system flow to three (3) agitation nozzles in the spray
tank. When the agitation switch is OFF, the agitation
valve motor is closed so no flow is directed to the tank
agitation nozzles.
An in−line flowmeter in the pressure side of the system
directly before the boom control valves measures flow
to the spray booms. The InfoCenter display can be used
by the operator to monitor information regarding spray
system operation.
The master boom valve located behind the spray tank
is controlled by the master boom switch on the spray
console. When the master boom switch is ON, system
flow is available for the spray boom sections (left, center
and right).
The spray boom switches (left, center or right) allow the
operator to control individual spray booms. When a
spray boom switch is ON, an actuator for that boom con-
trol valve opens the valve. This open valve directs sys-
tem flow to the spray nozzles located on the boom
section. An adjustable boom bypass valve exists in each
of the boom valve motors to prevent system pressure
changes when a boom section is shut off. Flow in excess
of control valve settings is directed back to the spray
tank. When a boom control switch is OFF, the boom con-
trol valve is closed so no flow is available to that spray
boom section.
Battery current for spray system fuses, switches, relays
and other components is provided by the main power re-
lay when the machine ignition switch is in the START or
RUN position. For spray system electrical component
information and test procedures, see Chapter 5 − Elec-
trical System in this manual.
Spray
System