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NMP Rev. 18 - Operating Instructions
EN
10.2 DESIGNATION OF PARTS
Nr. Designation
14.00 Pump casing
14.12 Plug (draining)
14.20 Gasket
14.24 Screw
14.28 Nut
14.46 Plug
15.00 Strainer cover
15.04 O-ring
15.08 Screw
15.12 Hand wheel
15.50 Strainer basket
28.00 Impeller
28.04 Impeller nut
28.20 Key
32.00 Lantern bracket
32.30 Guard
32.32 Screw
32.33 Caged Nut
36.00 Mechanical seal
36.50 Circlip
46.00 Deflector
70.20 Screw
70.21 Washer
73.00 Pump-side bearing
76.00 Motor casing with winding
76.04 Cable gland
76.16 Support
76.20 Pin
76.54 Terminal box, set
78.00 Shaft with rotor packet
81.00 Fan-side bearing
82.00 Motor end shield, fan side
82.04 Compensating spring
82.08 Screw
88.00 Motor fan
88.04 Circlip
90.00 Fan cover
90.04 Screw
94.00 Capacitor
98.00 Terminal box cover
98.04 Screw
98.08 Gasket
11. TROUBLESHOOTING
WARNING:
Turn off the power supply before performing any operations.
Do not allow the pump or motor to run when dry even for a short period
Strictly follow the user instructions and if necessary contact an authorised service centre
PROBLEM
1) The engine does
not start
2) Pump blocked
3)The pump func-
tions but no water
comes out
4) Insufficient flow
5) Noise and vibrations
from the pump
6) Leakage from the
mechanical seal
PROBABLE CAUSES
1a) Unsuitable power supply
1b) Incorrect electrical connections
1c) Engine overload protective device cuts in.
1d) Blown or defective fuses
1e) Shaft blocked
1f) Motor failed
2a) Prolonged periods of inactivity .
2b) Presence of solid bodies in the impeller
2c) Bearings blocked
3a) Presence of air inside the pump or suction pipe
3b) Possible infiltration of air.
3c) Foot valve blocked or suction pipe not fully
immersed in liquid
3d) Suction filter blocked
4a) Pipes and accessories with diameter too small
4b) Presence of deposits or solid bodies in the
impeller
4c) Rotor deteriorated
4d) Worn rotor and pump case
4e) Gases dissolved in the water
4f) Excessive viscosity of the liquid pumped
4g) Incorrect direction of rotation
5a) Worn bearings
5b) Unbalanced power supply
6a) The mechanical seal has functioned when dry or
has stuck
6b) Mechanical seal scored by presence of abrasive
parts in the liquid pumped
6c) Mechanical seal unsuitable for the type of
application
6d) Slight initial drip during filling or on first start-up
POSSIBLE REMEDIES
1a) Check that the mains frequency and voltage are suitable.
1b) Connect the power supply cable correctly. Check the setting of the
thermal overload protection.
1c) Check the power supply and make sure that the pump shaft is
turning freely. Check the setting of the thermal overload protection.
1d) Replace the fuses, check points a) and c)
1e) See “Blocked pump” instruction booklet
1f) Repair or replace the engine.
2a) Unblock the pump by using a screw driver to turn the relevant notch
on the back of the shaft.
2b) Remove any solid foreign bodies inside the impeller
2c) Replace the bearings.
3a) Release the air from the pump using the delivery control valve.
3b) Check which part is not tight and seal the connection.
3c) Clean or replace the bottom valve and use a suitable suction pipe .
3d) Clean the filter, if necessary, replace it . See point 2b) also.
4a) Use pipes and accessories suitable for the specific application
4b) Clean the impeller and install a suction filter
4c) Replace the impeller
4d) Replace the impeller and the pump casing
4e) Perform the opening and closing manoeuvres through the feeder
gate
4f) The pump is unsuitable
4g) Invert the electrical connections in the terminal board
5a) Replace the bearings
5b) Check that the mains voltage is right
In cases 6a), 6b) and 6c), replace the seal
6a) Make sure that the pump casing is full of liquid and that all the air has
been expelled.
6b) Install a suction filter and use a seal suited to the characteristics of
the liquid being pumped.
6c) Choose a seal with characteristics suitable for the specific application
6d) Wait for the seal to adjust to the rotation of the shaft. If the problem
persists, see points 6a), 6b) or 6c).
Changes reserved.
IST NMP Rev18 10_2022.qxp_MXS 11_03con gall 21/09/22 12:31 Pagina 13
