JLG 1250AJP Operation & Safety Manual page 56

Machine Operation
4.3.2 Envelope Control System
The Envelope Control System is the primary means of controlling the working positions
of the tower and main boom within the stability and structural requirements of the
machine.
The main boom must be controlled in maximum angle and minimum angle to avoid
entering a position that could compromise backward stability and avoid main boom to
tower boom interference. The tower boom must be controlled by permitting only
specific combinations of tower length and tower angle to avoid entering a position that
could compromise forward and backward stability (see Tower Path Control System).
Recognized failures within this system will result in control by the Electrical Retrieval
System (refer to the Service Manual), reduced function speeds, and BCS warning light
illumination. After retrieval the boom will be restricted from leaving the transport
position until the failure is resolved.
Boom position violations outside of the allowable envelope will result in reduced
function speeds, BCS warning light illumination, and restriction of functions. Attempts to
operate restricted functions will cause the BCS warning light to flash and the platform
alarm to sound.
Violations of the tower path (with a healthy control system) will cause the automatic
combined operation of tower lift and tower telescope to be suspended. A forward tower
path violation can be resolved by operating the tower lift up switch (tower telescope
out without auto tower lift up) or the tower lift down switch (tower lift down without
auto tower telescope in). A backward tower path violation can be resolved by operating
the tower lift up switch (tower lift up without auto tower telescope out) or the tower lift
down switch (tower telescope in without auto tower lift down).
The restricted functions due to backward tower envelope violations are disallowing
automatic tower lift down, automatic tower telescope out, main lift up and down, main
telescope in, jib, swing, drive and steer.
The restricted functions due to forward tower envelope violations are disallowing
automatic tower lift up, automatic tower telescope in, main lift up and down, main
telescope out, jib, swing, drive and steer.
The restricted functions due to maximum main boom envelope violations are
disallowing tower lift up and down, main lift up, main telescope in, jib, swing and drive.
The restricted functions due to minimum main boom envelope violations are
disallowing main lift down, swing and drive.
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31222384 1250AJP