User guide

7
ER 934 C ER 944 C ER 954 C Material Handlers
Reliability
Backed by more than 30 years experience in the construction of electric excava-
tors, Liebherr designed the new ER 934 C, ER 944 C and ER 954 C with the aim of
providing top performance whatever the challenge might be. The structure of the
machine, using components from our own manufacture for the electric drive, has
been completely rethought, and so moves away from simply being an adaptation
of a diesel-engine machine. Being intended for key functions in the organization
of industrial sites, Liebherr electric Material Handlers provide a very high level of
reliability. The service life of the hydraulic components has also been increased,
thanks to the smoother movement of the electric drive. The concept of the single
actuator (one single electric motor for all the hydraulic functions) allows all the
low-voltage functions to be concentrated in a single box.
Electrical
system
Totally integrated into the structure of the uppercarriages
and accommodated in a metal container, the electric cabinet
provides a three-fold level of protection to the components
of the electrical system:
- Mechanical (insulation from vibrations and from the pos-
sible impact of falling objects)
- Heat (maintains a constant temperature thanks to the heat-
ing resistors which prevent corrosion from condensation)
- Electrical earthing of the structure and disconnection from
current is controlled from the cab by way of a motorised
circuit-breaker.
Protected
electric cabinet
The electric cabinet, such as the collecting pipe, provides
IP55 class protection. A filtered ventilation system which
avoids any dust penetration and, with permanent ventila-
tion, ensures the thermal balance of all the components.
Electric motor
Liebherr electric excavators are equipped with motors espe-
cially designed for really tough applications. The dimensions
of the motor allow for the full power to be drawn from the
kinematic chain, and so maximises the performance of the
machine especially in the combined movements. The motor
can resist a momentary overload of up to +25 % of its rated
capacities. Protected against penetration by water and dust,
its properties correspond to protection class IP55.
The temperature of the roller bearings and other bearing
elements is constantly monitored, and, in the event of over-
heating, the operator is warned of malfunction on the con-
sole at the driving position.
Cooling system
•Generousdimensions
for high cooling capacity
•Verticalarrangementforincreased
efficiency and minimal incursion of
foreign bodies
•Poweredbyathermostatically
regulated hydraulic motor
•Hingedtoallowforcomplete
cleaning
•Reversibleactuationofthefan
(without time limit) as option
Undercarriage
•TheundercarriagesarethoseoftheEW
or S-EW diesel machines for industrial
applications, flat or ribbed tiles
•Theundercarriagesaredesignedand
built especially for electric excavators:
- side cable opening
- armoured junction box
- electrical collecting pipe