Manitowoc 777 Service And Maintenance Manual

Reference Only
ELECTRIC SYSTEM 777 SERVICE MANUAL
3-22 Published 10-01-2012, Control # 045-08
Table 3-4
Operating Limits
Listed below are limits which turn on the operating limit alert (yellow light and continuous buzzer). When the alert comes
on, OPERATING LIMIT group of digital display will indicate which limit has been reached; take corrective action.
Display Reading Function Response Corrective Action
BLOCK UP
Load drums stop hoisting and boom or
jib hoist stops lowering.
Lower corresponding load or raise boom
or jib.
BOOM MAXIMUM DOWN Boom stops lowering [3]. Raise boom.
BOOM MAXIMUM UP Boom stops rising [3]. Lower boom.
CONFIRM MODE
All drums inoperable until an operating
mode is selected and confirmed.
Select and confirm the desired operating
mode (see Operating Controls for
procedure).
DRUM 1 MAXIMUM BAIL [2]
Drum stops hoisting. Operate drum in lowering direction.DRUM 2 MAXIMUM BAIL [2]
DRUM 8 MAXIMUM BAIL [2]
DRUM 1 MINIMUM BAIL [2]
Drum stops lowering. Operate drum in hoisting direction.DRUM 2 MINIMUM BAIL [2]
DRUM 8 MINIMUM BAIL [2]
DRUM 1 PAWL IN
Drum doesn’t lower or stops lowering.
Disengage pawl. It may be necessary to
hoist slightly before pawl will disengage.
DRUM 2 PAWL IN
DRUM 8 PAWL IN [2]
COUNTERWEIGHT MAX UP
Boom hoist inoperable in lowering
direction.
Disconnect and store counterweight
lifting pendants (see Operating
Controls).
JIB BELOW HORIZONTAL [2]
Luffing jib operable. See capacity chart
for luffing jib minimum operating angles.
Raise luffing jib above horizontal.
LOAD MOMENT
All load drums stop hoisting and boom
and luffing jib hoist stop lowering.
Land load on load drum or raise boom or
jib.
LUFFING JIB MAX DOWN [2]
Luffing jib stops lowering when boom to
jib angle is 60°.
Raise luffing jib.
LUFFING JIB MAX UP [2]
Luffing jib stops raising when boom to jib
angle is 168°.
Lower luffing jib.
FUNCTION IS PARKED
Function inoperable because it is
parked.
Turn corresponding park switch off or sit
down in operator’s seat.
CYLINDER ALIGNMENT
Boom cylinders out of alignment. Stops
boom movement.
Check hydraulic system for blockage or
replace problem cylinder encoder.
BOOM HOIST MOTION
Unintended boom motion in either
direction.
Boom hoist inoperable in either direction
(cannot boom up or down).
Stop and restart engine to correct fault
(reboot programmable controller).
Troubleshoot system to determine
cause of fault (electronic displacement
control or pump).

Manitowoc 777 Specifications

General

Brand	Manitowoc
Model	777
Category	Construction Equipment
Language	English