Operation And Maintenance; Lubrication And Maintenance; Filters; Periodic Checks - Grundfos MTH Series Installation And Operating Instructions Manual

Fig. 5 Vent valve position
3. See the correct direction of rotation of the pump
on the motor fan cover. When seen from the top,
the pump should rotate counter-clockwise.
4. Start the pump and check the direction of
rotation.
5. Open the discharge isolating valve a little.
6. If the pump is fitted with a vent valve, this valve
must be closed when a steady stream of liquid
runs out of it.
7. Completely open the discharge isolating valve.
The pump has now been vented and is ready for
operation.

7. Operation and maintenance

Note: The pump is not allowed to run against a
closed discharge valve for more than approx.
5 minutes as this will cause an increase in
temperature/formation of steam in the pump which
may cause damage to the pump.

7.1 Lubrication and maintenance

Pumps installed in accordance with these instruc-
tions require very little maintenance.
The mechanical shaft seal is self-adjusting and has
wear-resistant seal rings which are lubricated and
cooled by the pumped liquid.
The pump bearings are also lubricated by the
pumped liquid. The motor ball bearings are grease
packed and sealed for life. No further lubrication is
necessary.
Pumps from 4 kW and up have angular contact
bearings.

7.2 Filters

Chip trays, filters, etc. should be cleaned at regular
intervals to ensure a correct flow of liquid.
8

7.3 Periodic checks

At regular intervals, depending on the conditions and
time of operation, the following checks should be
made:
• Check the quantity of liquid and operating
pressure.
• Check that there are no leaks.
• Check that the motor is not overheating.
• Check the tripping of the motor starter.
• Check that all controls are operating satisfactorily.
If the above checks do not reveal any abnormal
operating details, no further checks are necessary.
Should any faults be found, check the symptoms
with section 10. Fault finding chart.

8. Service

If a pump has been used for pumping
liquids which are injurious to human health
or poisonous, it will be classified as con-
taminated.
A contaminated pump must not be sent to Grundfos
for service until Grundfos has received all necessary
details about the pumped liquid, etc. Otherwise
Grundfos can refuse to accept the pump for
servicing.
Possible costs of returning the pump are to be paid
by the customer.