Versalift VO-452-MHI Operator's Manual page 41

Emergency operation may be required if an operator
is injured or the hydraulic system malfunctions. The
purpose of this chapter is to help qualified operators
become proficient with the controls and features
designed to accommodate emergency operation and
to describe the procedures for responding to
emergency situations. In any emergency the first
priority is always the safety of the personnel involved.
Before attempts are made to rescue personnel
always make sure the unit has not become electrically
energized. It is important to follow standard work
practices and safety regulations.
DANGER:
TO RESCUE PERSONNEL ON THE VO-350/355
UNIT ALWAYS MAKE SURE THAT THE TRUCK
AND THE AERIAL LIFT HAVE NOT BECOME
ELECTRICALLY ENERGIZED. CONTACT MADE
BY RESCUERS FROM THE GROUND WITH AN
ENERGIZED UNIT COULD CAUSE DEATH OR
SERIOUS INJURY.
CONTROL SELECTOR (Platform Override) -
When a situation requires the upper controls be
overridden (i.e. an injured operator in the platform)
use the control selector to select the lower controls
for operation of the lift. This will render the upper
controls inoperable and the lower controls can be
used to lower the operator to the ground.
BLEEDER PORTS - If the hydraulic system
becomes inoperable with an operator aloft, bleeder
ports on the cylinders (Figure 5.2 and 5.3) can be
used to lower the booms and return the operator to
the ground. Qualified personnel at the site are
responsible for selecting the path of boom descent.
The unit may be equipped with two different type of
bleeder ports. Refer to Figure 5.1 for identification
and proper procedures for loosening the bleeder
ports. Be prepared for a flow of hot oil escaping
around the bleeder port and step away from the boom
path of descent. The speed at which the lower boom
drifts down depends on the rate of oil loss.
VERSALIFT VO-452/455/460-MHI
EMERGENCY OPERATION
BEFORE ATTEMPTING
Bleeder Ports
Figure 5.1
Set Screw Type Bleeder - Turn the set screw slowly
using an Allen wrench to release load. Do not turn
the body. Oil is released from the hole on the side of
hex body.
Plug Type Bleeder - Turn the entire plug slowly
using a wrench to release load. Do not remove the
plug. Oil is released from the notch in the threads.
Torque to 15-20 ft-lbs. after use.
Bleeder Ports On The Upper Boom Cylinder
Figure 5.2
Bleeder Ports On The Lower Boom Cylinder
Figure 5.3
MANUAL ROTATION - If the hydraulic system
becomes inoperable the lift rotation system can be
operated manually. Before manual rotation is
attempted, remove the plugs from the motor test ports
on the dual counter-balance valve manifold located
on the rotation motor (Figure 5.4). This allows oil to
be piloted during rotation of the lift. Be prepared for
a flow of oil escaping from the motor test ports. Rotate
the lift by using a 7/8 in. hex socket, an extension,
and a ratchet to rotate the gearbox input shaft
accessible through the access hole on the turret.
5-1 39049-01 01/17