Manual Descent System - JLG E300AJ Operation And Safety Manual

5.5

MANUAL DESCENT SYSTEM

The manual descent system is used, in the event of total power fail-
ure or in case the key is not accessible to the ground personnel, to
lower the upper and lower booms using gravity. The jib lift cylinder
must be pumped down. To operate the manual descent system, pro-
ceed as follows:
1.
Locate the manual descent knob on the boom function
valve. Push the knob in to lower the tower and pull the knob
out to lower the main boom. The knob must be held in place
to perform the lowering function; it is spring loaded to
return to center when released. Install handle into manual
descent pump and lower the selected cylinders by pumping
the handle until the boom is completely lowered.
2.
If equipped with a jib, locate the split ring on the boom func-
tion valve. Push the split ring in to lower the jib or pull the
split ring out to raise the jib by pumping the handle until it is
completely lowered or raised. Stow the handle in bracket
provided.
31215000
SECTION 5 - EMERGENCY PROCEDURES
5-3