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Check that the direction of rotation is as shown by the arrow
on the upper cover (34.02): i.e. counter-clockwise when
viewing the motor from the fan end.
Otherwise disconnect
electrical power and reverse the connections of two phases.
Check that the pump works within its field of performance and
that the absorbed current shown on the name-plate is not
exceeded. Otherwise adjust the delivery gate valve or the
setting of any pressure switches.
If a priming loss occurs (interruption of delivery flow, despite
opened gate valves) or if a pressure oscillation is indicated on
the pressure gauge, repeat the venting operation on the suction
side (2), make sure all the suction pipe couplings are perfectly
sealed and tighten the air vent plug (2) and the draining plugs
(3) on the suction side (f
ig.3
).
ATTENTION: when the pump is located above the water
level
(suction lift operation,
fig. 2A
),
after a long idle peri-
od, before restarting the unit, check that the pump is
still filled with liquid and vented.
Otherwise, check for proper operation (opening and closing) of
the foot valve and fill the pump with liquid (see
section 7.2.
).
Never run the pump for more than five minutes
with a closed gate valve.
Prolonged operation without a change of water in the
pump causes dangerous increases of temperature and
pressure.
In systems in which it may be possible to operate with a closed
delivery gate valve, install a bypass valve (
fig. 2
) to ensure a
minimum flow
of about: 1.6 m
3
/h for
MXV 50-16
; 3 m
3
/h for
MXV 65-32
; 5 m
3
/h for
MXV 80-48
.
When the water is overheated due to prolonged operation with
a closed port, stop the pump before opening the gate valve.
To avoid any risk of danger to users and the creation of harmful
thermal stress in the pump and system due to large temperature
differentials, wait until the water has cooled inside the pump before
starting again or before opening the drainage and filling plugs.
Care must be taken when the pumped fluid has a
high temperature. Do not touch the fluid when its
temperature is higher than 60 ˚C. Do not touch the
pump or motor when their surface temperature is
higher than 80 ˚C.
8. Maintenance and monitoring pump operation
Under normal operating conditions the pump-motor unit will not
require maintenance.
Conduct routine inspection on the pump and connected parts to
check for a perfect seal.
Check the seal on the shaft from the outside through the
coupling guard.
The special funnel-shaped upper cover is designed to contain
any small initial leaks.
Keep the pump and surrounding part clean so as to be able to
immediately detect any outward leakage.
Clean the filter in the suction pipe and/or foot valve at regular
intervals; check performance and absorbed current.
The ball bearings in the motor and the ball bearing in the pump
(66.00 - see
section 9.2
) have permanent lubrication.
No regreasing is necessary.
See the operating instructions of the motor (if supplied).
Remove any excess grease expelled from the ball-bearing
(66.00) after the first period of operation.
In the case of water containing chloride
(chlorine or sea water)
the risk of corrosion increases in stagnant water conditions
(also with an increase in temperature and decrease of pH
value). In these cases, if the pump remains inactive for long pe-
riods, it must be emptied completely.
For good measure, as for temporary operation with dirty liq-
uids, run the pump briefly with clean water to remove deposits.
Or, after draining, perform the washing operation, inserting
clean water (at least 40 litres) into the filling hole (1 ) on the
delivery side and allowing it to come out of the draining hole (3)
on the suction side (
fig.3
).
When the pump remains inactive it must be emptied
completely if there is a risk of freezing
. Remove both plugs
(14.12), (position 3,
fig.3
).
Before starting the motor again fill the pump completely with
liquid (see
section 7.2.
) and make sure the shaft is not jammed
by encrustation, sticking of the faces of the mechanical seal or
other causes. In the event that the shaft cannot be moved by
hand, the pump has to be dismantled and cleaned.
Disconnect electrical power before any servicing
operation and make sure the pump cannot be
accidentally switched on.
9. Dismantling
Before dismantling, close the gate valves in the suction and
delivery pipes and empty the pump casing (
fig. 3
).
For dismantling and re-assembly refer to the section drawing
(
section 13.
) and
figures 4, 5, 6
.
Dismantling and inspection of all internal parts can be carried
out without removing the pump casing (14.00) from the pipeline.
Sequence for dismantling:
1. Mark the position of the motor on the lantern bracket (32.00),
and the position of the lantern bracket on the upper cover
(34.02), ... on the external jacket (14.02), ... on the pump
casing (14.00).
2. Remove the screw (32.32) with the washer (32.31) and the
coupling guard (32.30).
3. Loosen the screws (64.25) of the coupling (64.22).
ATTENTION
: to avoid compressing the spring of the mechanical
seal (36.00) because of axial shifting of the shaft (64.00), we
recommend to loosen the screws (64.25) of the coupling
(64.22) even only for
removing or replacing the motor.
Afterward reposition the shaft (64.00) as indicated in
section 10.2
.
4. Disconnect the power cable from the terminal box, remove
the screws (70.18) with the nuts (70.19) and
remove the
motor
away from the coupling (64.22) (
fig.4a
).
5. Remove the screws (61.07) and
remove the lantern brack-
et
(32.00), complete with bearing (66.00) and coupling
(64.22) from the upper cover (34.02) and from the shaft
(64.00) (
fig.4b
).
6. Remove the nuts (61.04) and washers (61.03) from the
tiebolts (61.02).
7.
Remove the upper cover
(34.02) from the shaft (64.00) and
from the external jacket (14.02) - or with the external jacket
from the pump casing (14.00) - with the aid of a mallet or
lever, exercising pressure in alternate operations, from di-
ametrically opposite positions (
fig.4c
).
Once the upper cover (34.02) has been removed, all the
internal parts can be extracted from the pump casing (14.00).
4.93.216
32.31
32.32
14.02
36.00
61.02
14.00
70.18
70.19
64.00
66.18
99.00
66.00
32.00
64.22
64.25
61.07
32.31
32.30
66.19
34.02
61.03
61.04
a
b
c
Fig. 4 a Removal of motor
b Removal of lantern bracket
c Removal of upper cover
9