Terex T780 - Making a Typical Lift

Making a Typical Lift
LIFT PROCEDURE In making lifts, the operator must successfully coordinate several crane
functions. These include the boom raise/lower, boom extend/retract, load hoist/lower and
swing functions. Although experienced operators tend to operate two or more of these
functions simultaneously, the lift procedure can be broken down into the following
sequence of operations.
OUTRIGGERS Set the outriggers as follows before initiating any lifting operations:
1.
Remove the outrigger beam retaining pins, extend beams, and reinstall retaining pins.
2. To set the four(4) outriggers evenly, operate switches to raise crane to a level position.
When level, retract jacks (together) at one end of crane an inch or so, and then extend
them again (together) until crane is level. Then repeat this process for the opposite end
of crane. This equalizes pressure in all four jacks. The controls for the out and down
outriggers are mounted on the dash. The extend/retract master switch must be
actuated before the appropriate function switches can be actuated to operate the
outriggers.
FRONT OUTRIGGER JACK This jack is intended to support the front of the crane only
and should never be used to level the crane. Set this jack only after the four outriggers
are set and the crane is leveled.
The red light on the dash will be on if the front jack is not fully retracted. It will remain
on any time the front outrigger jack is extended.
NOTE: When setting front outrigger, run the engine at IDLE only. High RPM will
increase jack cylinder hydraulic pressure, causing excessive force on the carrier
frame. Extend the front outrigger jack cylinder until the pad is on the ground
and you sense a slight lifting motion of the carrier frame. An automatic low
pressure relief valve system will prevent excessive loading on the carrier frame
during the setting of the front outrigger jack.
The fifth(5th) outrigger must be properly set to operate crane with 360° load
rating chart capacities.
360° load rating chart capacities apply only to machines equipped with a front
outrigger jack and all five (5) outrigger jacks properly set. If the front (5th) outrigger
jack is not properly set, the work area is restricted to the over side and over rear areas
as shown on the Crane Working Positions diagram found in the load chart. In this
case, use the 360° load ratings in the over side work areas.
The outrigger beams MUST BE PROPERLY POSITIONED FOR THE LOAD RATING
CHART BEING USED, and the crane leveled prior to extending the boom or lifting
loads. To achieve this condition, the vertical jack cylinders should be extended until
the tires are raised free of the supporting surface.
T300-1_T500-1_T780
Operating Instructions
188 P/N 12261-683
REVISED: January 2015