Control and operation

Operating the excavator in safety modes

Safety operation of the Diesel engine

The engine can also be switched into safety operation automatically, as an example consecutively to a communication default in the control system.

In safety operation, the engine works with reduced output in comparison with the normal operation.

In safety operation the stop of the Diesel engine is achieved just like in normal operation, while turning back the ignition key to the "off" position.

It is not possible to return to normal operation when the engine is running, the rocker switch S71 must be tilted back from safety operation into normal operation (position AUTO) only when the excavator is turned off.

Notice!

In safety operation, the communication between the electronic control box of the engine and the main circuit of the excavator may be no longer possible. The engine operating error codes are in this case no longer displayed on the screen.

The occurrence of an operating error of the engine is then indicated as follows:

Caution!

In case the warning light H60 lights up, the operator must shut the engine down as soon as possible and recognize which error has occurred. It's the operator's own responsibility to decide if the machine can be maintained operating or not!

In safety operation the following functions remain available: coolant or of the charge air. the control box of the engine. At the opposite, the following functions are no longer operative: en the maximum permitted coolant or charging air temperature has been exceeded.

Diesel engine RPM adjustment in safety mode

In normal operation, the desired value for the engine RPM is entered via the buttons S86, S228 and S229, and the engine speed is controlled in consequence by the electronic system of the machine.

If the engine has been started in safety mode via the rocker switch S71 so it can be operated only with two different RPM values. The commutation between the two values is achieved via the switch S72.

Manually choose one of the values:

S72 tilted to the left, the engine runs at the lower safety RPM. S72 tilted to the right, the engine runs at the upper safety RPM..

Notice!

When the engine is switched automatically into safety operation, the current engine speed is maintained as long as the engine is not shutdown.

Safety operation of the servo control circuits

During normal operation, the servo pressure supply to the swing brake and to the joysticks and pedals is controlled over the electronic circuit of the machine.

While tilting the switch S73 in safety position, this servo pressure supply can be enforced, and is maintained even in case of a trouble in the normal control circuit.

Tilt the safety lever down.

Commute the switch S73 into safety position (tilt to the right). the three indicator symbols S73a, S73b and S73c appear on the display. the joysticks and pedals are supplied with servo pressure. the swing brake is released.

Danger!

The safety mode must be turned on only temporarily and in order to move the machine for emergency reasons and when, due to a trouble in the normal control circuit, releasing the swing brake or supplying the pilot controls is hindered. In safety mode, the swing brake will be released as soon as the ignition key is turned to contact position, and the normal brake control is out of function.

Inform all personnel involved in the operation or maintenance of the machine that the safety mode has been turned on and that, by the fact, the control of the swing brake is modified.

Locate the trouble which makes the operation in safety mode necessary and get it repaired as quickly as possible.

Note !

Even with the switch S73 in safety position, the servo pressure supplying the joysticks and pedals is interrupted when tilting up the safety lever .

3.5.2Safety operation of the main working pumps

During normal operation of the excavator, the electronic horsepower control continuously adjusts the pumps flow to the pressure level of the working circuits

If a trouble occurs in the circuit of the regulator, the pumps stay in maximum angle and therefore the engine is overloaded.

Locate the trouble and get it repaired as quickly as possible.

3.6Recovering, towing the machine

3.6.1Prerequisites

Earth-moving machines can only be towed when their brakes and steering are functional.

The machine may only be towed in exceptional circumstances, eg. in order to move the machine away from a dangerous place for repair.

Notes!

Respect the local traffic instructions and safety rules of labour inspection and adapt beforehand the machine, its transport means, the loading and lashing material to the local permitted conditions.

Towing the machine is problematic and is always carried out at the owner's risk. Damage or accidents occurring during towing of the machine cannot be covered by the manufacturer's guarantee under any circumstances.

The equipment/ bucket must never be used to recover or tow the machine.

3.6.2Process recommendations

Secure the towing / recovering area according to the local traffic recommendations and safety rules of labour inspection.

Towing earth-moving machines should be done only with help of tow-bars, cables or ropes sufficiently sized.

Danger!

Risk of injury due to a torn rope! Staying near the rope is forbidden. Never use towing equipment damaged, kinked or torn.

Caution!

The stowage ears, who are situated on the four undercarriage ends, are only provided for the transport on a loader. The stowage ears must never be used for the towing.

Caution!

Tow-bars or ropes are sufficiently sized when the value of their loads resistance to rupture corresponds to at least threefold the traction force of the towing machine. The equipment to fix tow-bars or ropes are, for example, towing coupling, clevis, rings or hooks.

Check for brake functions properly.

Caution!

While towing the machine, the multi-plate brake in the drive transmissions must be released.

This means that the engine will have to be started so that the pressure in the hydraulic lines can be removed. If the engine cannot be restarted or if there is a defect in the hydraulic system, the drive transmissions can also be manually depressurized. For more information on this, consult LIEBHERR customer service.

Check the equipment position properly, means boom, stick and bucket cylinders out in order to position the bucket about 20 - 30 cm over earth level.

If present, lift up the dozer blade.

Caution!

To position the equipment / dozer blade properly, the engine must be started so that the pressure in the hydraulics lines is effective. If the engine cannot be restarted or if there is a defect in the hydraulic system, the dozer blade cylinders can also be manually depressurized. For more information on this, consult LIEBHERR customer service.

Mount the towing equipment around the crown base. Place a protection between crown and towing equipment, to avoid any damages on both.