Lull 6K Service Manual - Manual (Page 525)

Frame Tilt and Oscillation
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K 7-23
4. When the proximity switch (S1) energizes the proximity switch relay
(R1), power is also directed from relay (R1) to the rear oscillation lock
warning light relay (R3). When the warning light relay is energized, the
path to ground for the warning light is interrupted and the oscillation
lock warning light goes out.
5. As the service brake is applied, the normally open service brake
pressure switch (S2) closes. Power is directed to the service brake
pressure switch relay (R2), energizing it. This breaks the power
directed to the solenoid valve (V1) and locks the rear axle cylinder.
6. Even though the boom is below 40°, when the service brake is applied
so there is no power to the solenoid valve at the stabilizer block and the
stabilizing cylinder is locked, it is still possible to frame tilt.
7. Power is still supplied to the frame tilt lockout solenoid valve (V2) and
the frame tilt override pressure switch (S3). When the frame tilt
controller is activated (in the operator’s compartment), it directs pilot
pressure to the frame tilt valve section. The frame tilt override pressure
switch (S3) senses this pressure from the controller and closes. This
directs power to the solenoid valve (V1) on the stabilizer block which
unlocks the rear oscillation lock cylinder. This enables the main frame
to be tilted with the boom below 40° and with the service brake applied.
Testing Rear Oscillation Lock Circuit
Use Table 7-1 for testing the rear oscillation lock circuit.
Table 7-1: Rear Oscillation Lock Circuit Test Matrix
OPERATING
PARAMETERS
S1
PROXIMITY
SWITCH
S2
SERVICE
BRAKE
SWITCH
S3
FRAME TILT
OVERRIDE
SWITCH
R1
RELAY #1
PIN #86
R2
RELAY #2
PIN #86
R3
RELAY #3
PIN #86
V1
STABILIZER
SOLENOID
V2
FRAME TILT
LOCKOUT
SOLENOID
REAR
OSC.
LOCKED
LIGHT (10)
Boom below 40°
Service brake released Closed Open Open 12 Volts 0 Volts 12 Volts Energized
(Unlocked) Energized
Frame tilt allowed Off
Boom below 40°
Service brake applied Closed Closed Open 12 Volts 12 Volts 12 Volts De-energized
(Locked) De-energized
Frame tilt allowed Off
Boom above 40°
Service brake applied
Operating frame tilt Closed Closed Closed 12 Volts 12 Volts 12 Volts Energized
(Unlocked) Energized while
frame tilting Off
Boom above 40°
Service brake released Open Open Open 0 Volts 0 Volts 0 Volts De-energized
(Locked) De-energized
Frame tilt disabled On
Boom above 40°
Service brake applied Open Closed Open 0 Volts 12 Volts 0 Volts De-energized
(Locked) De-energized
Frame tilt disabled On
Boom above 40°
(Attempting to frame tilt) Open Depends on
brake
position Open 0 Volts Depends on
brake
position 0 Volts De-energized
(Locked) De-energized
Frame tile disabled On