JLG 1850SJ, Руководство по обслуживанию и ремонту, Страница: 97 / 712

SECTION 3 - CHASSIS & TURNTABLE
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3.15 SWING CONTROL SYSTEM
The swing control system uses the turntable swing angle sen-
sor in addition to the Drive Orientation System (DOS) proxim-
ity switch to prevent turntable swing while the axles are
retracted. Swing will be allowed to +/- 35 degrees (before the
DOS proximity switch trips) to facilitate positioning the turnta-
ble for transport of the machine. Attempts to swing past this
position will be disallowed by the control system and the
operator will be prompted via the LCD display in the platform
to swing in the opposite direction to return the boom behind
the rear wheels. Once the axles are extended the boom has
360 degree continuous turntable swing. If the turntable is
swung past +/- 35° when the boom is lowered into the trans-
port position, the operator will have to swing the turntable
back within the rear wheels before attempting to retract the
axles.
3.16 CHASSIS TILT INDICATOR SYSTEM
The Chassis Tilt Indicator System measures turntable angle
with respect to level ground. The tilt sensor (mounted to a
bracket on the side of the turntable near the boom pivot pin)
has three settings; 3.0 side tilt, 5.0 omni directional tilt, and an
8.0 omni directional tilt.
The 5.0 omni directional angle setting is used for the purpose
of warning the operator by means of the chassis tilt light in the
platform display panel. Additionally when used in conjunction
with the Beyond Transport - Drive Speed Cutback System, the
tilt sensor will cause an alarm to sound and automatically put
all functions in the creep speed mode and drive will be cut
out. With the exception of the drive being cut out, this is a
warning system only indicating to the operator that the
machine has reached the out of level limit. The machine will
continue to function. The operator is responsible to prevent
the machine from attaining an unstable position.
The 3.0° side tilt setting is used in conjunction with the main
boom length and when exceeded, imposes the same func-
tionality as the 5.0° omni directional setting plus prevents
boom telescope out. The side tilt setting is ignored when the
main boom length is less than 1477.7 inches in the 500 lb
mode or 1442.8 inches in the 1000 lb mode.
The 8.0º angle is used exclusively for the purpose of automati-
cally shifting the drive motors to the maximum displacement
position (slow speed).
The control system responds to indicated angle readings 0.3
degree smaller than the required angles to account for calibra-
tion and sensor variation.
3.17 AUXILIARY POWER SYSTEM
The auxiliary power system is intended as a secondary means
of moving the boom in the event of primary power loss. This
system uses an electric motor/pump unit powered by two12V
batteries capable of operating all functions except drive, con-
trolled arc, controlled boom angle, and envelope tracking.
During main lift up or down functions, no other functions are
permitted and during main lift up functions, automatic plat-
form leveling is not active but jib leveling is active. To reduce
battery demand and extend system run time, the auxiliary
power functionality differs from the primary power functional-
ity. The auxiliary power main lift down function supplies pilot
pressure to the main lift cylinder. This allows gravity to lower
the boom. The system redirects discharge oil from the main lift
cylinder to retract the main telescope cylinder. At high main
boom angles the envelope may be encroached during lift
down requiring the operator to use main telescope in.
When the main boom is retracted to transport length, the
main telescope in valve is dropped out and lift down is oper-
ated alone allowing platform to reach the ground. This not
only greatly reduces power required for these functions but
also lowers the boom within the envelope regardless of start-
ing position. Jib lift down function may then be operated
allowing platform to reach ground level. Envelope control and
moment control remain active during auxiliary power func-
tion.