Document number: ED.03783.00.001.ENG rev 4 Page 112 of 153
point area, such that the cylinders are not loaded. Do not continue the operation until the cause
of the deviation is found and resolved.
7.3.2.1 Reduce expected load functionality
The reduce expected load functionality should be used when the load that needs to be lifted is
not completely level at the start of the lift or when putting the load down. The functionality is
explained below for starting to lift a load that is not level and lowering a load that is not
supported by a level support. Note that for this functionality the hysteresis between the units
should be switched off.
Hazard
When the hysteresis is switched off the program does not keep the stroke of
the units within a specified limit. When the load is not properly monitored
with for example theodolites, this might lead to instability and causes
potential hazards to personnel and damage to the system.
The stroke of the units are normally controlled and kept within hysteresis. This would mean that
one of the units starts to lift the load while the other units are not yet in contact. The unit that is in
contact will exert the maximum force on the load while the load is not yet supported at the other
locations. This might lead to undesired effects.
1. With the reduce expected load functionality the maximum force applied by the system is
limited to the set percentage, 25% for example.
2. When this percentage is reached the system will stop and the unit that has reached the
previously defined percentage can be disabled.
3. The other units can now be extended till the next unit reaches the load.
4. Steps 1 till 3 should be repeated till all units are in contact with the load.
5. The next step is to increase the expected load to 50% and repeat steps 1 till 4.
6. Further increase the expected load to 75% and 100% while repeating steps 1 till 5.
When lowering a load on a support that is not level, the steps are more or less reversed as
described below:
1. With the reduce expected load functionality the force applied by the system is limited to
the set minimum percentage, 75% for example.
2. When this percentage is reached the system will stop and the unit that has reached this
minimum level can be disabled.
3. The other units can now be retracted till the next unit reaches the minimum percentage.
4. Steps 1 till 3 should be repeated till all units are at the minimum percentage.
5. The next step is to decrease the expected load to 50% and repeat steps 1 till 4.
6. Further decrease the expected load to 25% and 0% while repeating steps 1 till 5.
To Next Page
Loading...
