Paccar CARCO 50B, Руководство по обслуживанию, Страница: 18 / 61

16
P
390/410 PSI
15 PSI
F
LG L
BRAKE LUBE
& COOLING
ORIFICE
LUBE
FS
315/370
PSI
PS
A
1
C2 BR C1
15 PSI
REEL OUT
CLUTCH
BRAKE
REEL IN
CLUTCH
ORIFICE ORIFICE
PRESSURE
SWITCH
ACCUMULATOR
FS
BULL GEAR
PUMP
FILTER
SUCTION
STRAINER
A
C2 BR C1
SYS
2
3
13
4
6
7
11
9
12
O O O O O O O
LOW PRESSURE
HIGH PRESSURE
10
PS
BR
C2
FS
C1
RED (1)
BROWN (4)
ORANGE (7)
BLACK (11) - GROUND
BLUE (2)
WHITE (6)
WHITE W/ BLACK STRIPE (3)
BLACK (11) - GROUND
GREEN (9)
FILTER
HEAD A
A
12 11 10 9 8 7
6 5 4 3 2 1
(-) GROUND
(+) 24 VDC (+) 0 TO 24 VDC
CONTROL VALVE DIAGNOSTICS PLUG
BRAKE-OFF
During BRAKE-OFF, 24 volts DC will be seen at the red and
blue wires within the winch case, and at pins 1 and 2 of the
diagnostics connector on the wiring harness. As the joystick
lever moves from the BRAKE-ON position into the full BRAKE-
OFF position, the voltage at the brown wire and pin 4 increase
proportionally from 0 to 24 volts DC.
To release the spring-applied brake requires the following com-
ponents:
Item 2 - Brake Control Solenoid
Item 6 - Relief Valve
Item 10 - Main Pressure Solenoid Valve
Item 13 - Accumulator Holding Valve
Item A - Accumulator
In BRAKE-OFF, only the brake is released; the directional
clutches are not affected. The brake circuit is unique in that the
brake release oil pressure is proportional to the movement of
the joystick lever into the BRAKE-OFF position. All other winch
functions receive full control pressure, 400 PSI (2760kPa) and
full 24 volts DC to the solenoid valves. The main pressure sole-
noid valve (10) and the accumulator holding valve (13)
receives 24 volts DC through the blue wire within the winch
case. The full flow of the pump is directed to the oil pressure
gallery in the control valve. The pressure switch (11) is not
used to control the maximum control system oil pressure when
a winch function is selected. Instead of the pressure switch
(11), the relief valve (6) limits the maximum pressure in the
control circuit to approximately 400 PSI (2760 kPa).
After first pressing the enable switch, the movement of the joy-
stick lever toward the BRAKE-OFF position will cause an
increase in the voltage sent to the brake control solenoid (2)
through the brown wire and pin 4 on the diagnostics plug. As
voltage increases, the valve opens further to send higher con-
trol pressure to release the spring-applied brake. When the joy-
stick lever is placed in the full BRAKE-OFF position, full 24 volt
DC current is sent to the control valve and full 400 PSI (2760
kPa) oil pressure is sent to fully release the brake.
When the joystick lever is released, the electrical signal to the
solenoids is lost, the solenoid valves exhaust the control oil
pressure to the winch sump, and the spring-applied brake
reapplies to hold the load. The control valve returns to the
BRAKE-ON mode and the pressure maintenance system
begins slowly cycling to maintain a stand-by supply of control
oil pressure.
BRAKE-OFF
Voltage is proportional to control handle move-
ment. If a test light is used, brightness will be
proportional to control handle movement.