Manitowoc Grove GRT880, Operator'S Manual

Page: 146 / 202

SET-UP AND INSTALLATION GRT880 OPERATOR MANUAL
4-4
Published 3-25-2020, Control # 643-04
Machines with Main and Auxiliary Hoists
If the main boom extension or fly section is not used, then the
bridging plug must be plugged into the distributor socket on
the main boom and the lifting limit switch weight must be
mounted on the main boom.
If the crane is operated with a main boom extension and/or
with a lattice insert, then the connecting cable must be
mounted between the distributor socket on the extension or
on the top section and the distributor socket on the main
boom. In addition, weights must be fitted to both the A2B
switch of the main boom and the extension or fly section.
If the boom extension or lattice insert are in working position
and if the main boom is not equipped with a hoist rope, then
the weight of the A2B switch on the main boom must be
removed to prevent endangering personnel or damaging
equipment.
After electrical connections have been checked to ensure
the system is properly connected for the respective crane
configuration, the following checks must be made:
1. Check electrical wiring connecting various parts of the
system for physical damage.
2. Check A2B switches and weights for free movement.
3. Inspect spring cable drum for smooth running, initial
drum tension, and correct cable winding.
4. Inspect mechanical and electrical installation of power
measurement sockets on the lattice insert (if present).
Check Hoist limit switch warning light and acoustic alarm as
follows:
1. Manually raise weight fitted on the A2B switch. As soon
as weight is raised, the acoustic alarm should sound and
A2B switch warning should display.
2. Using the main hoist, pull hook block slowly against the
A2B switch weight. As soon as the hook block raises the
weight, the acoustic alarm should be triggered, the
A2B
switch warning should display, and the main hoist should
switch off. Lower the hook block slightly to eliminate this
condition.
3. Slowly lower the boom to bring about a potential hoist
limit situation. As soon as the hook block raises the
weight, the acoustic alarm should sound, the
A2B switch
warning should display, and the luffing gear should
switch off. Lower the hook block slightly to eliminate this
condition.
4. Slowly extend (telescope out) the boom to bring about a
potential hoist limit situation. As soon as the hook block
raises the weight, the acoustic alarm should sound, the
A2B switch warning should display, and the telescoping
function should switch off. Lower the hook block slightly
to eliminate this condition.
5. If crane is equipped with a boom extension or lattice
insert, the inspection procedure must be repeated for
the A2B switch of the extension/top section.
6. Verify display of main boom length agrees with actual
boom length.
7. Verify display of main boom angle agrees with actual
boom angles.
8. Verify display of the crane operating radius agrees with
the actual radius.
9. Verify load display by lifting a load of known weight.
Load display accuracy must be within the tolerance
range.
WARNING
The following tests must be performed with care to
prevent personnel injury or crane damage. Proper
functioning of the Crane Control System (CCS) requires
successful completion of these tests before starting work.
If the operator cannot see the hook block approaching the
pulley head, this task must be assigned to an assistant
(slinger).
The crane operator must be prepared to stop the crane
immediately if the CCS is not working correctly, i.e. when
warning indicators do not display, the acoustic alarm does
not sound, and crane movements such as raising,
extending and luffing are not disabled.
WARNING
If warning indicators and audible alarm do not function as
described and crane movements are not switched off, the
system is not working properly. The malfunction must be
corrected before starting work.