DAB S4, Instruction For Installation And Maintenance

Page: 14 / 136

ENGLISH
12
8. ELECTRICAL CONNECTIONS
For the electrical connections, please refer to the SAFETY INSTRUCTIONS BOOKLET
EN-60335-1
The mains voltage must be the same as that on the motor data plate.
Connect to the mains with a two-pole switch, with contact opening distance of at
least 3 mm.
Correctly size the cross section of the power supply cable in relation to the length
to avoid voltage losses.
Install a high-sensitivity differential switch (0.03A) as additional protection or
compatible with the control equipment (e.g. Inverter).
In fixed installations, International Standards require the use of isolating switches
and fuse holder bases.
The electrical connection to any electronic equipment against dry-running must be
carried out in compliance with the wiring diagrams given in the use and
maintenance manuals of the electronic control units.
Cable connections below the water level must have a vulcanized joint to ensure
tightness.
Before starting, the insulation value to earth must be checked.
9. START-UP
1. After lowering the pump into the well, start it up at a reduced flow rate, checking the current consumption
and the relative pressure. Gradually increase the flow rate to check for changes in the water level and any
sand content. In the case of large quantities of sand in the water being transported, the internal parts of
the pump will be subject to considerable wear. If the sand content is too high, the pump may become
blocked or unprimed. In this case, it is necessary to contact the company that made the well for the
necessary assistance. If the flow stops, switch off the pump immediately to avoid dry running or running
with the motor blocked.
2. For three-phase motors, check the direction of rotation. The correct direction supplies higher pressure.
3. Check the current consumption, which should drop to the value of the rated current no more than 2
seconds after switching on. If this does not occur, the pump must be stopped immediately and the cause
of the fault must be sought. During operation, the current consumption must not, under any
circumstances, exceed the rated current.
4. Run the pump for a few hours to verify that the borehole flow rate is sufficient in relation to the pump
itself.
If the water does not come out at the first start even if the motor is running normally and the maximum
suction depth has been respected, it is probable that the pump will not be able to expel the air inside the
delivery pipe, thus preventing the valve from opening. Fill the delivery pipe completely with water and repeat
the start-up operation.