20
6.4.5.1
RADIO SYSTEM PROTECTION DEVICES
The radio control system is provided with some protection systems that are automatically started in case of:
- radio interference on the crane working area that influences the radio control frequency range
- transmitter capacity field exceeded (keyboard)
On these cases the system locks all the functions.
Press and release the emergency button to restore the functions
In addition, when the battery charge is too low for safety operations the system is blocked, the green LED
turns off and the radio module interrupts transmissions with the unit.
The keyboard is provided with battery energy saving system to reduce battery consumption.
When the keyboard remains unused for at least 15 minutes, the radio system is set to “energy save”, the
green led turns off and the radio module interrupts the transmission with the unit (receiver).
Press and release the emergency button to unblock.
6.4.6
PROPORTIONAL MONO-FUNCTION REGULATION HYDRAULIC UNIT
(Pict.11)
The unit is consisting of two separate aluminium blocks.
The upper section includes the proportional adjusting valve (
VR
) and the manual bypass control valve (
OM
) of
the proportional regulator.
The lower section includes the main relief valve (
VM
), the dump valve (
EV9
) and the control solenoid valves
(
EV
…
A
–
EV
…
B
), two for each movement.
The solenoid valves:
EV9
–
EV3B
–
EV2B
–
EV1B
–
EV1A
are equipped with a manual override, to be used
only for emergency (failure of the electronic control unit or the button strip, lack of power supply).
In such cases it is necessary to proceed as follows:
a
)
fully turn counter-clockwise the valve
handwheel (
OM
) in order to bypass the
proportional valve (
VR
)
b
)
fully turn counter-clockwise the manual
override of the valve coupled to the
desired movement (extension re-entry,
boom lowering, etc.).
c
)
finally fully turn counter-clockwise the
manual override of the valve (
EV9
), in
order to activate the desired movement
d
)
once the standard working conditions of
the crane are restored, always remember
to close completely the manual overrides,
by turning them clockwise.
e
)
finally close completely the bypass valve
(
OM
) by turning the handwheel
clockwise.
Pict.11
EV3A
EV9
VR
EV4B
EV3B
EV2B
EV1B
OM
VM
EV4A
EV2A
EV1A
