Use and maintenance manual Self-propelled aerial platforms Page 54
7.2.10
Operation check of dead-man button safety system
The platform dead-man pedal is for enabling the operation controls of the machine from the platform control station.
If the control panel is selected but the dead-man button is not pressed the green light on the platform (O – Fig.5) is flashing
and the machine cannot be operated.
Pressing the dead-man button, the operation controls of the machine are activated and the condition is signalled by a steady
green led (O – Fig.5).
Once the pedal has been pressed, the controls are to be activated within 2 seconds, after which they are deactivated and the
green light will flash again.
7.2.11
Braking valves adjustment (counter-balancing
valves)
These valves check the minimum operating pressure during
drive (in both running directions) and affect the dynamic
braking and the driving speed. Normally, these valves do not
require any adjustment, since they are calibrated at the factory
before the machine is delivered.
Calibration of both braking valves is required:
-
If the traction plate
A
is to be replaced;
-
If one or both braking valves are to be replaced.
To calibrate the braking valves:
-
Locate the two hydraulic units
A
called "traction plates";
-
Locate the braking valves
B
(two for each running
direction);
-
Connect a pressure gauge of at least 250-bar scale to the
provided quick coupling in the hydraulic control unit (1/4" BSP);
-
From the platform control panel select the minimum drive speed;
-
Unscrew the lock-nuts
C
of the adjusting dowel;
-
From the platform control post drive the machine (in the direction controlled by the valve) on a flat ground in
straightforward direction and adjust the braking valve (relevant to that running direction) by means of adjusting dowel
D
so as to achieve the required pressure value (call the nearest Service Centre to ask for the exact value);
-
Once the required pressure value has been achieved, check that the valve controlling the braking in the opposite
direction has maintained its adjustment;
-
Once adjustments are complete (pressure values in the two directions must not vary by more than ±5 bar), lock the
adjustment dowel by means of the lock-nut.
AS THIS OPERATION IS VERY IMPORTANT IT IS TO BE CARRIED OUT BY SPECIALIZED TECHNICIANS ONLY.
CALL THE TECHNICAL SUPPORT
Fig. 27
A
B
B
C
D
