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* Check that all the crane's control levers are in the middle position and that they also return to the
middle position.
* Refer to the crane's daily inspection.
* Start the pump and adjust its output according to the crane's requirements (refer to specifica-
tions). You can get the information about the outputs for various speeds from the pump's supplier,
if necessary.
* If work is carried out at low temperature, let oil circulate for a while through the valve system with
a low flow. Then slowly perform all the operating movements, back and forth, in order to make the
gaskets more flexible before they receive maximum pressure. Rotate the rotator and run an empty
grapple back and forth for heating of the hoses in the boom system and to prevent damage from
the cold. The lowest recommended operating temperature is - 25° C, and the crane manufacturer's
warranty does not cover the damage caused by the use in lower temperatures, -25° C or lower.
* It should be noted that in lower temperatures hydraulic gaskets wear faster and the probability
that hoses and steel structures become more susceptible and steel structure's probability of brittle
fracture increases. When working in temperatures below - 25°C
normal loads in order to avoid unnecessary damage.
* In low temperatures, the advantage is to equip the oil tank of the hydraulic system with a heater.
* The manufacturer cannot guarantee the operation of the crane components at temperatures be-
low -30° C. The components most sensitive to disturbances caused by the cold are the pilot control
of the leg support valve and the priority valve controlling the flow to the leg support valve.
* When starting the pump at a temperature of less than -30° C, disorder may occur in the priority
valve controlling the flow to the stabilizer valve, wherein the priority valve remains at the position
corresponding to its rest position and controls the output of the pump completely and not at all to
the valve of the crane. If the equipment is equipped with a free circulation valve, disconnect it from
the hydraulic circuit and start the pump again. Heat the oil, first by pumping the oil first with free
circulation. If the system has a dual circuit, the second circuit heats the priority valve circulating in
the same frame with it. Try again with the normal operation of the crane, when the oil is slightly
warmed up. The priority valve can also be heated by driving the stabilizer valve functions back and
forth with a minimum pump capacity.
* When controlling the stabilizer valve from the control location of the crane, when the temperature
is low, the leg support control can be switched on and off more slowly than normal or the pilot con-
trol does not respond at all. Heat the stabilizer leg valve by driving the stabilizer valve functions
back and forth directly from the valve levers.
* Similarly, in very warm conditions one should ensure that the hydraulic oil does not overheat
°
(<75°C
). A too high oil temperature may cause damage to the gaskets and it also reduces oil life.
•
* Adjust the crane tower with the stabilizer legs to a position as vertical as possible.
* Stop work immediately if you notice any impeding danger.
* Work only in adequate lighting.
Notice the crane's trajectories and positions where it can run into
the truck's cabinet or other structures.
°
it is preferable to lift smaller than
42
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