Control and operation

Working with the machine

Note!

If the machine is used frequently or for long periods for hammer work, the hydraulic oil will be more contaminated than in usual conditions.

Adapt the maintenance intervals for hydraulic oil and for return filter cartridges to the work in heavy dust conditions.

3.4.10Commutation of control for an additional attachment (option)

Danger!

Wenn the commutation of the control is turned on, the correspondence between the controls and the working movements is changed. There is a danger of accident due to an unintentional movement by a not or bad informed machine driver.

When the key is removed from the switch or when the touch is gone out, the machine can be operated only with the usual control system, installed at machine delivery.

It is the responsibility of the owner of the machine to decide which operator and for which works must or is approved to operate the machine with the activated special control system.

Caution!

Check out the functions of the additional controls when starting the machine, and especially when a commutation of control is activated.

Standard control

Fig. 3-76 Commutation of standard control for an additional attachment

The additionnal attachment can be operated alternatively with the left double pedal or with the right joystick. The commutation of control can be activated with the key switch S114 on the rear right control desk.

Turn the key switch S114 to select the joystick position

The additional attachment is now operated with the right joystick (movements to e and f).

Control and operation

The bucket tilt function is now operated with the left double pedal (m-k).

The key is locked in the switch S114

Turn the key switch S114 to select the foot pedal position

The additional attachment is now operated with the left double pedal again. The key can be removed from the switch S114

Proportional control

Mini joystick / Joystick

Fig. 3-77 Commutation of proportional control for an additional attachment

The additionnal attachment can be operated alternatively with the right mini joystick or with the right joystick. The commutation of control can be activated with the key switch S195 on the rear right control desk.

Turn the key switch S195 to select the joystick position

The additional attachment is now proportionally operated with the right joystick (movements to e and f).

The bucket tilt function is now operated with the right mini joystick (movements to X- and X+).

The key is locked in the switch S195.

Turn the key switch S195 to select the mini joystick position

The additional attachment is now proportionally operated with the right mini joystick again.

The key can be removed from the switch S195.

Mini joystick / Pedals

Fig. 3-78 Commutation of proportional control for an additional attachment

The additionnal attachment can be operated alternatively with the right mini joystick or with the left pedals. The commutation of control can be activated with the touch on the right control desk.

Press the touch.

LED in the touch illuminates. The additional attachment is now proportionally operated with the right mini joystick.

Press the touch.

LED in the touch goes out. The additional attachment is again proportionally operated with the left pedals.

3.4.11Cut off by end switches of attachment movements (option)

Function

On some specific attachments, or on attachment showing particular cinematic capacities (for example on industrial attachments) certain movement(s) may be stopped automatically by electrical end switches..

The installation of a cylinder cut off can fulfill different purposes :

–It can serve to avoid the repeated stopping over the mechanical buffers, which would cause damage to hydraulic cylinders or to main structures.

–Frequently, the cylinder disconnection serves to restrict the possible working area and in particular:

•the working height (as an ex. when working under a warehouse roof, under electrical overhead lines, ... ).

•the maximal reach (as an ex. to avoid the possible development of high reaction forces in the completely stretched position of the attachment).

•the minimal reach (as an ex. so that, when retracting an industrial stick, the load taken up in the grapple cannot come into the range of the operator's cab and damage it).

Danger!

The disconnection of a cylinder movement does not constitute a safety device! It must only be considered as an assistance to the driver during actuation of a movement near a zone to be avoided !

Caution!

Avoid fast movements of an attachment part, if you move it in the vicinity of a cut off point.

With fast movements, the sudden disconnection can cause a rocking motion of the machine or a strong pendular movement of the attached grapple.

Danger!

In some cases, the equipment can enter the zone normally prohibited by the proximity switches (and for example arrive too close to the cab), due to: –the oscillations of the working tool (for ex. a grapple) and because of the variation of its dimensions between the open position the closed position. –Because of the inertia of the attachment at the disconnection. The stopping distance can increase by 0,5 m according to the temperature of oil or the type of equipment and 1,0 m additional following the speed and/or the load in the working tool.

You must keep a safety margin from at least 1.5 m to the dangerous position. The precision of the setting lies in the responsibility of the machine operator!

Note!

A movement is interrupted only in the direction which corresponds to the crossing of the cut off point to enter the prohibited zone. The movement in opposite direction which allows to leave the danger area remains always possible.

Adjustment of the cut off point

Prerequesite:

Bring the attachment part whose movement has to be restricted into the position where the cut off of movement must occur.

Setting:

Loosen the screws 1

Shift the slide 2 so that its end just enters the

Retighten the screws 1.

Check the position for which the cut off of the cylinder movement occurs. If necessary repeat the adjustment procedure and check the cut off position again.

Note !

Should in the cut off position, the slide and the limit switch be in a difficult to reach raised position, then the adjustment can also be done with the equipment in a stretched and close to the ground position, first in an approximate way and afterwards while correcting by successive approaches this adjustment until the point of cut off matches exactly.

Unlocking of movements cut off

Fig. 3-81 Switch for the unlocking of attachment movements cut off

An attachment movement cut off can be unlocked while turning the key switch S54 in the rear right control desk. Thus it remains possible to move a disconnected attachment part beyond the cut off point.

Unlocking of a movement is possible only if the movement has already been cut off by the end switch.

Danger!

The displacement of attachment parts within a range normally prohibited by a cylinder cut off can bring to a situation presenting a danger for injury of persons and/or damage of material.

The operator is in all the cases responsible for the accidents which can occur when the attachment is working inside the zone of danger while keeping unlocked a cylinder movement cut off.

Turn the key switch S54 turned to the right (position I).

Tilt up or down the rocker switch S55 mounted to the left joystick handle. the movement cut off is unlocked, it remains possible to move the attachmrent inside the prohibited zone as long as the switch S55 is kept depressed. Should a special attachment comprise two different automatic stops of movement, so the key switch S54 must be turned to the left (position II) to be able to release from the second automatic limitation.

No unlocking via the rocker switch S55 is possible with the switch S54 in neutral (position 0).

Note!

On machines destined to the north-American market and also fitted with a lifting magnet controlled via the rocker switch S55, the left push buttons S5L at top of the left joystick handle must be used to unlock the limitation.

3.4.12Use of the excavator for lifting loads overhead

Under "lifting loads overhead" it is understood the lifting, transporting and unloading of loads requiring a securing method (ropes, chains, or other permitted lifting accessories) and where personnel are required to assist in securing and unloading the load. This includes, for example, the lifting and unloading of pipes, shaft-top supporting rings or containers.

Danger!

An hydraulic excavator may only be operated for lifting loads overhead if all the prescribed safety devices are present and functioning correctly.

In accordance with European standard EN 474-5, and so to guarantee the protections of the persons attaching or removing the loads during lifting operations, the machines used for lifting loads overhead must be equipped with the following safety devices:

– a load hooking system ensuring the safe attaching and removing of the loads (optional equipment)

Safe hooking systems include for example lifting hooks which are mounted in place of the bucket. Safety lifting hooks welded directly to the bucket are also allowed.

– an overload warning device (optional extra)

The overload warning device must alert the machine operator visually or acoustically if the permitted load value has been reached or exceeded, according to the rated lift capacity chart.

– a boom lowering control device (such as load check valves) to prevent unintentional lowering or dropping of the boom because of the weight of the load, which could happen if a line in this hydraulic circuit suddenly develops a leak (for example, should a hydraulic line break or a hose burst,...).

This boom lowering control device must correspond with the requirements of ISO 8643.

Such a boom lowering device can be installed as an option on all models up to R924C, it is serially installed on all models R934C and above.

– a rated lift capacity chart (commonly called load chart), attached inside the cab and within the view of the operator..

If the points referred to above are not or are only partially fulfilled, the machine may not be used for lifting loads overhead

Every LIEBHERR hydraulic excavator can be fitted with all the safety devices required for lifting loads operation.

Danger!

Only employ sling ropes and accessories which are permitted for lifting operation, regularly checked and in good condition.

No person may fasten or unfasten a load without approval of the operator and this person may only approach the load from one side. The operator may only approve this action when the excavator has stopped and the attachment is not moving.

Never lift loads over people.

3.4.13Overload warning device (Option)

General

The overload warning device shows the machine operator when the permissible load carrying capacity has been reached both optically, via the warning symbol and acoustically, via a buzzer.

The overload warning device is designed to prevent the permissible load torque being exceeded unintentionally. In this event, the working radius will have to be reduced or the load set down without enlarging the working radius.

The overload warning device does not relieve the operator of the responsibility of lifting loads which are either known or are permitted on the basis of the load carrying capacity of the machine.

The permissible load carrying capacity is dependent on the condition of the machine (chassis, equipment) and should be taken from the load chart in the cab.

The load carrying capacity values attain a maximum of 75% of the tipping capacity or 87 % of the hydraulic lifting power in accordance with ISO 10567.

Note!

The load values are subject to change if equipment parts and work tools are attached or dismounted.

Always refer to the load chart, and make sure which are the attachment parts whose weights are considered or not in the indications of the rated lift capacity chart. As an example, if the weight of the bucket is considered in the lift capacity chart and the bucket is dismounted for the lifting works, then the lifting capacities can be increased by the weight of the bucket.

In the same way, if the bucket tilt cylinder, the shifting lever and the connecting rod are dismounted even thought their weights are considered in the lift capacity chart, then the indicated lifting capacities can be increased by the weights of these parts.

With the specified load, the machine can be rotated from 360° on even and horizontal ground.

Using the overload warning device

Danger!

When carrying out load hoisting work with the machine, the relevant accident prevention precautions are to be observed. The overload warning device does not shut down the machine if the permissible load torque is exceeded. The operator of the machine will only be informed of the situation.

Mode of operation

The overload warning device comprises a constant pressure switch which is connected to the piston of the boom hydraulic cylinders.

If the load pressure in the boom hydraulic cylinders reaches the level of the shift pressure, the pressure switch emits a signal, the warning symbol appears on screen and the buzzer sounds.

The shift pressure in the pressure switch is selected in such a way that the stability factors can be maintained even if in an unsupported state (small stationary torque).

Starting the overload warning device

Danger!

No load hoisting work may be carried out if the overload warning device is defective. Have the overload warning device repaired by a professional.

Press switch S18

Overload warning device is activated. LED in switch illuminates.

The operator must check the function of the overload warning device before each work shift.

To check the overload warning device, extend the boom hydraulic cylinders to the stop.

Push the joystick further in the direction Raise boom. The warning symbol must illuminate. The buzzer must sound.

Caution!

This is only a functional test of the warning system (qualitative test), but it does not mean that the adjustment is correct. For this reason, the overload device must in addition be checked by a professional in accordance with the testing and setting information provided in the service manual (quantitative test):

•before the first use of the overload warning device, •each time it is required by the locally applying regulation for lifting operation.

Deactivation of the overload warning device

Note!

For work using a bucket, deactivate the overload warning device, since the increased effort of the machine will cause the overload warning device to be permanently active.

Press switch S18 again. Overload warning device is deactivated. LED in the switch goes out.

3.4.14Hydraulically adjustable cab (option)

A hydraulically adjustable cab is an auxiliary device enabling the cab to be adjusted either in height or in inclination.

Danger!

When the cab is raised, the route the machine will be travelling must be even, free of all obstructions and must not have a gradient that could affect the stability of the machine.

Only adjust the cab when the machine is stationary. Ensure that no persons are within the machine’s danger area when carrying out the cab adjustment.

The hydraulic adjustment of the cab is possible when the machine is ready to ope-

Control and operation

rate, with the safety lever pushed up and the engine running. The hydraulic adjustment is controlled via the rotary switch S200 on the right side control panel.

Raising the driver’s cab:

Turn and keep turned to the left the rotary switch S200 the driver’s cab raises, as long as the rotary switch S200 is not released.

Lowering the driver’s cab:

Turn and keep turned to the right the rotary switch S200 the driver’s cab is lowered, as long as the rotary switch S200 is not released.

Emergency operations

If the control of the hydraulically adjustable cab is lost due to a trouble in the engine or another defect, it remains possible to lower the cab thanks to an emergency function.

The emergency lowering can be controlled from two different places: Emergency lowering from inside the cab: From the inside of the cab it is possible to engage the emergency lowering procedure using a shutoff valve located on the floor of the cab under the right control panel.

Turn the shutoff valve into position 2 the driver’s cab lowers as long as the shutoff valve is maintained in position 2. Return the shutoff valve into position 1 immediately after an emergency lowering.