JLG 1850SJ Service Manual - Manual (Page 90)

SECTION 4 - BOOM & PLATFORM
4-4 – JLG Lift – 3121619
automatically. If a fault occurs in the platform leveling system
the following will occur:
• Automatic platform leveling will stop (except when there is
a fault in only one sensor)
• The platform level fault indicator will flash
• The platform alarm will sound
• All functions will default to creep speed if in platform mode
and the boom is out of the transport position
To reset the fault the emergency stop switch should be recy-
cled.
Boom Control Select
The boom control select switch is mounted on the platform
control panel and allows the operator the ability to select
between two different modes of boom control functionality:
automatic and manual. While in either mode, the envelope
control system and moment control system remains active.
When the boom control is selected to the automatic boom
control position, lift and telescope movements are coordi-
nated by the control system as described in the controlled arc,
controlled boom angle, and envelope tracking descriptions.
These systems will remain active to automatically assist the
operator in keeping the boom within the envelope boundar-
ies. When operating in the automatic mode, the following
functionality characteristics should be noted.
• While operating Lift Up, the boom may also telescope out
(controlled arc)
• While operating Lift Down, the boom may also telescope in
(controlled arc)
• While operating Swing or Drive, the boom may lift up or lift
down (controlled boom angle)
• While operating Telescope In, the boom may lift down
when at high boom angles and the creep light is flashing
(envelope tracking)
In addition, when the boom control is selected to the auto-
matic position, the automatic platform leveling feature is
active during lift, telescope, swing, and drive movements as
described in the electronic platform leveling system descrip-
tion.
When the boom control is selected to the manual position, lift
and telescope movements are controlled separately by the
operator effectively turning off the controlled arc, controlled
boom angle, and envelope tracking systems. Without these
systems being active, the control system will stop the move-
ments of the boom when the envelope boundaries are
reached and the functions that could violate the envelope will
be restricted. The platform alarm will sound and the BCS light
will flash with attempts to operate a restricted function. In
addition, when the boom control is selected to the manual
position, the automatic platform leveling feature is active only
during lift movements.
4.2 BOOM REMOVAL AND INSTALLATION
Removal
1. If necessary, remove the platform.
2. If necessary, remove the jib.
3. Tag and disconnect hoses T2 T3, 7, 8, and Pressure Filter
lines from the main valve. Cap or plug all openings.