The load measuring system continuously determines the current load on the load hook. This value is necessary for many crane functions, especially for the overload protection.

The load measuring system must be calibrated once with an increased test load in order for the attached load to be evaluated.

For this work step, access from a laptop or tablet computer to KranOS is necessary. The user "Abnahme" (commissioning) (user level ‚[2]) must be logged in.

Requirements for the calibration:

─     A test load is necessary for the calibration.

─     The dimensions of the test load must be known exactly.

─     The dimensions of the test load should be at least 80% of the maximum load capacity of the crane and as close as possible to the maximum load capacity of the crane.

For the dynamic test of the maximum load capacity of the crane a test load of 110% of the maximum load capacity of the crane is usually used. In general, this can also be used for the calibration.

A load above the maximum load capacity of the crane may only be lifted by a qualified person for the test before the first commissioning of crane installations.

ABUControl blocks the lifting function for loads over 110% of the maximum load capacity of the crane. The load can no longer be lifted and can only be set down instead.

ABUControl blocks the lifting and lowering functions for loads over 130% of the maximum load capacity of the crane. The load can no longer be lifted or set down.

Log in as user "Abnahme" (commissioning) (user level [2]) in KranOS. See Connecting laptop or tablet computer with ABUControl, page  .

Select the desired hoist (e.g. Hoist 1) in the main menu.

●   The window for the requested hoist appears.

Click on the "Hoist calibration" menu item in the "Settings" menu (gear wheel on yellow background).

The area in the left of the "Hoist calibration" window is used for the calibration with an increased test load. Whereas the "Calibrating load sensor" button is only needed if the fixed point crosshead or the load sensor was replaced

●   The "Hoist calibration" window appears.

Select in the "Test load" selection field whether the load measuring system works with one or two sensors:

─     For all GM 800 to GM 7000 compact wire rope hoists, the load is measured with ONE sensor (with one measurement bolt in the fixed point crosshead).

─     For the GM modular wire rope hoist (from 09/2016), the load is measured with ONE load sensor (load measuring arm with a dual-equipped load sensor on the fixed point crosshead).

With earlier versions of the GM modular hoist (to 09/2016), the load is measured with TWO sensors (load measuring arm with two load sensors on the fixed point crosshead).

If necessary: Take the load and lifting tackle out of the load hook.

Lift/lower the empty load hook so that it hangs relatively far up, e.g. about a metre under the highest hook position.

●   The displayed value in the "Proportional value" line is a measured value without measurement unit, which is used to calculate the load later.

Click on the "Accept calibration value" button in the "Calibration at zero-load" column.

●   The current value is saved as zero-load.

Click on the "Test load" input field in the "Calibration at test load" column.

Input the test load dimensions.

Click on the "OK" button.

●   The input value is accepted.

Observe the applicable occupational health and safety regulations and lift the test load.

Wait until the test load hangs calmly in the load hook.

Click on the "Accept calibration value" button in the "Calibration at test load" column.

●   The current value is saved as test load.