Tighten drain plugs by hand. Do not use
pliers or other tools.
If necessary, use pliers only to unscrew.
Excessive torque may cause damage.
ATTENTION: after a long idle period, before
restarting the unit, fill the pump casing with
water and check with a screwdriver that the
shaft is not jammed.
If the shaft is jammed, dismantle the motor and
remove the cause.
7. Dismantling
Drain the pump casing before dismantling (see
fig. 4
and
section 10.
). For dismantling and
reassembly see construction in the cross-section
drawing (
section 12.
).
Remove the motor assembly with the lantern
bracket (32.00) from the pump casing (14.00), after
removing the screws (14.24), the nuts (14.28) and
the washers (14.29), levering them out with two
screwdrivers in diametrically opposed positions.
To remove the impeller (28.00) insert a large
straight-blade screwdriver in the slot on the shaft
(78.00) at the ventilation end.
Grip the impeller with one hand and unscrew it,
turning the shaft
counter-clockwise
and twisting
with both hands (
fig. 5a
).
If it is not possible to hold or move the shaft with
the screwdriver, remove the fan cover (90.00)
and motor fan (88.00) and unscrew the impeller
by gripping the shaft with a suitable wrench.
With the impeller the rotating part of the
mechanical seal (36.00) will be removed.
8. Assembling
To replace to
mechanical seal
(36.00) place the
rotating part of the seal on the impeller hub (28.00)
and push the spring right down as far as the front
shoulder. In this way, correct spring compression
will be ensured in subsequent assembly.
Lubricate the seal with water and align the
impeller on the motor shaft.
ATTENTION: with the three-phase models, to
avoid the unscrewing (and breaking) of the
impeller should the motor start rotating
backwards
, clean the threaded shaft end and
apply on the first half of the threaded part
Loctite 243.
If this type of product is not used, check the
direction of rotation before filling the pump (to
avoid unscrewing due to the resistant-force of the
water in the case of a backward rotation).
Grip the impeller with one hand and turn the shaft with
a screwdriver in the
clockwise
direction until tight.
With this operation the front surfaces of the
mechanical seal come into contact without rubbing
against each other during tightening (
fig. 5b
). Clean
the O-ring (14.20) and seal surfaces with water.
When replacing the motor assembly with the
impeller be careful to insert the locating lug
inside the pump casing
(14.00)
into the locating
slot on the diffuser cover
(27.00) (
fig. 6
).
ATTENTION:
to avoid leakage or failure due to
misalignment and localized overstressing, the
screws (14.24) with the nuts (14.28) must be
uniformly tightened with alternated crossover
tightening in diametrically opposed positions.
Tightening torque for screws (14.24): 7 Nm.
9. Spare parts
When ordering spare parts, please quote the data
stamped on the name-plate, the part designation
and the position number of each spare part
required (in accordance with the cross-section
drawing on
section 12.
).
Any pumps that require
inspection/repair must be drained
and carefully cleaned inside and
outside before dispatch/submission.
Changes reserved.
Fig. 4
Draining
Air inlet
Fig. 5
Dismantling (a) and remounting (b) the impeller
4.93.149
MPC
1, 2, 3, 4
MPC
5, 6, 7
14.00
14.20 32.00
27.00
14.00
27.00
Fig. 6
Locating lug/slot for assembling pump casing
(14.00) - diffuser cover (27.00).
11
