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Introduction
2-1 GENERAL DESCRIPTION
The XLB-4725A Boom Lift is designed and manufactured for positioning personnel with
their tools and equipment at overhead work locations. The rated work basket load capac-
ity is 450 lbs. (The older basket model capacity is 400 lbs. Refer to figures 6-16 and
6-16A for illustrations of the basket models). Basket elevation is by two hydraulic cylin-
ders acting on upper and lower boom sections. A hydraulic powered motor and worm
gear rotates the boom 360° around a vertical axis. The hydraulic power unit includes a
reservoir, pump, and control valves.
On the battery powered (DC Model) boom lift, a 24 Volt, 39 Amp, one horsepower, DC
electric motor drives the hydraulic pump. The DC motor is powered by four 6 Volt DC,
245 Amp-hour, deep charge batteries connected in series. A 40 amp, automatic, on-board
battery charger is provided for recharging the batteries at the end of each work
period.
On the gasoline engine powered (Gas Model) boom lift, a 4-cycle, 8 horsepower, gasoline
engine drives the hydraulic pump. A 12 volt DC storage battery powers the engine starter
circuit. An auxiliary voltage regulator/rectifier provides 18 amps maximum charge current
while the engine is running.
Two control panels use directional selector switches, rheostats, and proportional hydraulic
valves to control the direction and speed of boom lift and rotation. One set of operator
controls is provided for ground operation and another set is provided for operation from
the basket. Elevation and rotation controls are operational only when the moving boom
section is within a programmed safe operating zone. Only one boom motion is permitted
at a time, and only as long as the boom is within the safe operating zone. When a selected
boom motion reaches a safe operating limit, the motion ceases and another motion must
be selected within the safe operating zone.
Outrigger and wheel position interlock safety switches prevent lifting operations until the
four outriggers are properly deployed and the full weight of the boom lift is loaded onto
the outriggers.
Boom elevation speeds are adjustable from zero to 8 inches per second (0 to 40 ft/min). A
hydraulic hose failure at either retract-cylinder port will cause a velocity fuse to close and
stop the return oil flow. It is strongly recommended that no one adjust or tamper with
these safety devices. If service is required, please notify Bil-Jax for detailed instructions.
Emergency lowering of the basket is by a manual valve plunger on the front end of the
power compartment. Firmly pulling out and holding the valve plunger manually retracts
the upper boom lift cylinder.
The XLB-4725A Boom Lift cylinders will not rust or corrode during storage since the
cylinder rod is fully immersed in oil. It is important that the cylinder rods be kept clean
and undamaged for the protection of the cylinder head packings.
