DAB KV 10/2, Инструкция по установке и обслуживанию

Страница: 31 / 114

ENGLISH
26
Example 3: installation at sea level and fluid at t = 90°C
N.P.S.H. richiesta: 3,25 m
pb : 10,33 mcw (fig. 3, page 96)
Hr: 2,04 m
t: 90°C
pV: 7,035
m (fig. 4, page 96)
Z1 10,33 - 3,25 - 2,04 - 7,035 = -1,99 circa
In the last case, in order to operate correctly the pump must be fed with a positive head of 1.99 - 2 m, that is
the free surface of the water must be 2 m higher than the axis of the pump intake aperture.
N.B.: it is always good practice to leave a safety margin (0.5 m in the case of cold water) to
allow for errors or unexpected variations in the estimated data. This margin becomes
especially important with liquids at a temperature close to boiling point, because slight
temperature variations cause considerable differences in the working conditions. For
example in the third case, if instead of 90°C the water temperature reaches 95°C at any
time, the head required by the pump would no longer be 1.99 but 3.51 metres.
8. ELECTRICAL CONNECTION
Caution! always follow the safety regulations.
Scrupulously follow the wiring diagrams inside the terminal
board box and those on page 1 of this manual.
8.1 The electrical connections must be made exclusively by skilled personnel (see point 6.1) as
required by the safety regulations in force.
The requirements of the electric energy supply company must be scrupulously complied with.
In the case of three-phase motors with star-delta start, ensure that the switch-over time from star to
delta is as short as possible and that it falls within table 8.1 on page 94.
8.2 Before opening the terminal board and working on the pump, ensure that the power has been
switched off
8.3 Check the mains voltage before making any connection. If it is the same as the voltage on the data
plate, proceed to connect the wires to the terminal board,
giving priority to the earth lead. (Fig. E).
8.4 ENSURE THAT THE EARTH SYSTEM IS EFFICIENT AND THAT THERE IS THE
POSSIBILITY OF MAKING A GOOD CONNECTION.
8.5 The pumps must always be connected to an external switch.
8.6 Three-phase motors must be protected with special remote-control motor-protectors calibrated for
the current shown on the plate.
8.7 The terminal board may be arranged in four different positions (except the KVC series), turning
the motor through 90°. If necessary, proceed as follows (checking the references indicated with
those shown on the exploded views at the end of the manual):
KV 3/_ - KV 6/_ - KV 10/_ : remove the fan cover (13), releasing it from the groove in the motor
end cover (11). Remove the fan (12) from the rotor shaft by prising it off with two screwdrivers or
levers, levering on the cover (11). Unscrew the tie bolts (24) from the motor end cover (11) and
the discharge body (97). Remove the cover (11) and retain the thrust bearing (21). Turn the stator
(10) into the desired position. Fit the thrust bearing (21) onto the bearing (20) and place the motor
cover (11) on top. Tighten the four tie bolts (24) and check that the shaft is turning freely. If not,
slacken the tie bolts and tap a few times with a plastic hammer. Tighten the tie bolts again and
check that the shaft is turning freely. Fit the fan (12) onto the knurled end of the rotor shaft,
tapping lightly with the hammer, and fit the fan cover (13) onto the motor end cover.
KV 32/_ - KV 40/_ - KV 50/_ : loosen the four bolts (45) joining the motor flange (105) and the
support (3). Turn the motor into the desired position and replace the screws.
9. STARTING UP
9.1
Do not start the pump unless it has been completely filled with fluid.
Before starting up, check that the pump is properly primed; fill it completely with clean water by
means of the hole provided after having removed the filler cap (25) on the discharge body. This
ensures that the mechanical seal is well lubricated and that the pump immediately starts to work
regularly.
(Fig. E). The filler cap must then be put back in place. Dry operation causes
irreparable damage to the mechanical seal and the stuffing box seal.