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In the case of three-phase induction motors with Y / ∆ – connection it must be ensured that the change-
over points between star and delta follow on from one another very quickly. Longer change-over times
may result in pump damage (Table 2).
2.3.5.7. Final check
After completion all the above process check the coupling alignment once more as described in 2.3.4. Correct if there is
a fault. Rotate the pump rotor several times by hand. Make sure rotor rotates easily. Fix the safety guards in places then
run the unit until it warms up and normal operating conditions are reached. Now shut it down and make final alignment
by shimming driver only. Final alignment should be made at operating temperature.
Fix the coupling guard back in place. Do not operate the pump before doing so. This is a necessity for security
and job safety.
2.4. START UP / SHUT DOWN
2.4.1. Preparation
2.4.1.1. Lubrication Control
Grease lubricated bearings are factory packed with grease enough for one year operation before dispatch. Before
initial start up the pump it should be ascertained that no dirt has penetrated inside the bearing during transport or
installation on site. Otherwise, the bearings should be cleaned out and repacked with fresh grease before start up.
If the pump is stored for a long time before installation (more than 6 months) pump extra grease on bearings.
Oil lubricated pumps are dispatched without oil and this is indicated with a warning label. Fill the bearings housing
of this kind of pump with oil until the marked level on the gauge.
See 2.5. for lubricating.
2.4.1.2. Check the shaft seal (see 2.6.3)
2.4.1.3. Venting and Priming
Make sure that the pump and suction pipes are completely filled up with water. There is no problem for the pumps
which have positive suction head. If there is a valve on suction line, it must be opened and air taps are loosened to
enable the water replaces air in the pump, until it is completely full with water.
If there is a foot valve for the pump, which has suction lift, pump is filled up with water through the filling tap at the
highest point of the pump and the air is emptied out.
If the system has a vacuum pump, water is brought up in the rising pipe and filled up the pump through this vacuum
pump. When water is risen up to the highest point then the pump is started up.
Make sure the pump never runs dry.
Motor Power
≤ 30 kW
> 30 kW
Table 3
18
Y –set time
< 3 sec
> 5 sec
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