23. MOTOR COOLING GAP INSPECTION AND MAINTENANCE
WARNING
The cooling gap between the casing and motor housing of electric pumps with a motor cooling jacket must be periodically
serviced.
The frequency with which this operation must be carried out varies. It depends on the type of installation (vertical installations need servicing
less frequently than horizontal ones), the characteristics of the fluid used for cooling, the degree of purity, the tendency to form incrustations,
aggressiveness and the operating mode.
If the liquids contain solids, conduct an initial inspection within the first 50 hours service and repeat this a second time within the next 200 hours in
order to establish the correct servicing frequency, which will depend on the degree of cleanliness observed. Use clean external liquid if necessary.
If an optimum degree of cleanliness is observed in the gap during the above-mentioned inspections, periodical maintenance can be scheduled after
every 2,000-3,000 hours service.
Comply with the following instructions to clean the gap (see "section and nomenclature" chapter), always in conformity with the usual rules of
hygiene and safety:
1 - stop the electric pump and close the sluice valves on the intake/delivery pipes if installed.
2 - in submersed installations, remove the electric pump from the tank, disconnecting it from the delivery pipe.
3 - if the pump is installed in a dry chamber, it will not be possible to completely empty the hollow space through holes in the casing.
In this case, place a vessel under the electric pump in order to collect the liquid when the jacket is removed after having removed the
connecting pipes.
4 - check that the jacket can be fully removed from the motor casing without encountering obstructions such as walls, electrical cables or other.
5 - remove the three plugs keeping the jacket in position.
6 - remove the jacket using the threaded axial holes and levering on the cast iron eyelets.
7 - clean and carefully remove any scaling from the cooling fluid inlet and outlet ducts, the O-Rings and O-Ring housings, the external surface of the
motor casing and the inner jacket surface.
8 - once removed, the jacket remains harnessed by the power supply cables of the electric pump itself. If the jacket is cleaned in this condition, make
sure that the cables do not become damaged during the operation itself. If the cables are disconnected from the power panel to free the jacket,
protect their free ends from water and moisture.
9 - before the jacket is re-assembled, check that the O- Ring housings of the electric pump and jacket have been thoroughly cleaned. Now spread
them with silicone grease, check that the O-Rings are efficient and replace them if necessary.
10 - mount the O-Rings in their housings. Set the jacket in position until the anchoring brackets positioned the threaded plug holes.
24. INSPECTION OF PARTS SUBJECT TO WEAR
The life and performances of the pump parts vary with wear and corrosion according to the different conditions of use.
If the electric pump is examined for wear, comply with the following instructions also consulting the typical section diagram for the references within
brackets.
If the parts are partially or totally clogged by the solid material carried along by the conveyed fluid, thoroughly clean them with a jet of pressurized
water. To clean the hollow space between the impeller and the oil chamber shield, direct the pressurized jet from the pump casing delivery. This area
can only be perfectly cleaned after the impeller has been removed.
1. - Set the electric pump in a vertical position, checking that it stands firm.
2. - Unscrew the bolts (Pos. L20) from the pump casing. Now lift the motor unit plus the impeller and then set it in a horizontal position.
3. - Check the play between the wear ring (Pos. L6) and the collar of the impeller (Pos. L2). If the play exceeds 3 mm (difference between the inner
ring diameter and the impeller clearance diameter) replace the ring and/or the impeller or reset the impeller clearance diameter by applying a steel
ring with a thickness of at least 5 mm, subsequently machined in order to obtain a minimum 0.5 mm play (see fig. 1).
4. - Contact your nearest CAPRARI after-sales center if there is excessive wear on the impeller or pump casing. Always insist on genuine spare parts.
Use a wrench for M16 socket head screws to remove the impeller.
5. - Thoroughly clean the rubber parts, nuts and bolts before reassembling the individual components.
6. - Check that all parts are in a good condition. Replace any parts as may have been damaged during the disassembling operations or as have
deteriorated through wear.
7. - Check that the oil does not contain water. Change the seal on the pump side if this is the case.
Caprari S.p.A.
Fig. 1
Impeller clearance diameter
Inner ring diameter
K.M150R.. / K.250... / K.D300... / K.D350...
1,5 mm
(m x.diametral play = 3 mm)
á
0,25 mm
(min.diametral play = 0,5 mm)
GB
31