Specifications

Section 4: Using the machine 25/44
IMPORTANT
AUTOMATIC SPEED COMPENSATION
The machine has an automatic speed compensation system that permits the rain gun carriage to be reeled in at
a constant speed throughout the irrigation work.
This regulation is done by means of a control operated by a probe on the hose at the back of the machine and this
in turn acts on the main by-pass valves.
A machine with 175 meters of hose set for a reel in rate of 20 m/h must have an irrigation time of 8 h 45.
If there are more hours (10), there is very little compensation and the control lever must be moved upwards using
the holes on the lever (pos. 12, photo H). If there are less hours (7), compensation is high and the lever will be
moved downwards using the same reference holes.
MACHINE DRIVE AND SPEED ADJUSTMENT
Engage the drive lever (Pos. 7, photo H) by pulling it towards left and use the by-pass to engage the desired drive
speed (pos. 3, photo H).
To adjust the speed: slacken off knob (pos. 2 photo H), engage the manual by-pass valve (pos. 3, photo H). Set
the speed as required and then re-tighten knob (pos. 2, photo H) to lock the machine at that speed.
If the obtained speed is always too fast or too slow, a further adjusting must be made using the
transmissionm chain positioned under safety cover (pos.14 photo H). For this adjusting stop water feeding
to the machine (so that pressure indicated in manometer pos.1 photo H becomes "zero"), brake with the
handle pos.6 photo H firmly closing clockwise; open safety protection pos.14 photo H lifting it up. Now, in
order to decrease the speed, move the chain pos.9 photo H to the smaller diameter gorge of the pulley
no.10 and to that of bigger diameter of pulley no.11 photo H. Do the contrary to increase the speed.
When the machine is operated at maximum speed, the load loss inside the turbine
increase considerably but this is normal.
IMPORTANT
ATTENTION! THE ABOVE OPERATION MUST BE MADE ONLY WHEN THE MACHINE IS
STOPPED. DON'T TRY TO CHANGE THE CHAIN WHILE THE MACHINE IS WORKING: IT CAN
BE DANGEROUS!!
It is good standard practice to make the definitive reeling in rate setting after the lever has been engaged for some
minutes (pos. 7, photo H) so that the hose has been pit into traction.
The working pressure and reeling in rate can be read off the instruments on the machine (pos. 1 and 4 photo H).
Refer to page 27/44 for instructions on the VDO digital tachometer.