3 Commissioning and start up
3.1 Verification of rated current
Please refer to the motor nameplate for the values of rated current required for relay
setting.
3.2 Switching ON mains
The pump set should be switched ON only if water level in well/sump is above limit
given in figure 2.
3 .3 Checking the direction of rotation
For Three-phase motors
1) Let the pumping set run for a short time against a closed discharge valve, in both
the directions of rotation and check the flow. Reversing of poles of connection,
reverses the direction of rotation. The higher flow rate gives the direction of
rotation. OR
2) Using pressure gauge, check the discharge pressure in both the direction of
rotations. The higher value corresponds to the correct direction of rotation. OR
3) By visual inspection see the flow rate in both cases. If water comes out up to the
short length through the raiser pipe, flow rate is lower while if it comes farther,
results in higher flow rate. The higher flow indicates the correct direction of
rotation.
For Single-phase motors
In case of single-phase AC motors the direction of rotation of the motor itself
corresponds to the correct direction of rotation of the pump, irrespective of mode of
connection to the power supply.
3.4 Operation against a closed discharge valve
Pumps should not be allowed to run against a closed discharge valve for longer than 5
minutes. This would cause the water in the pump to warm up quickly and the heat
would be transferred to the motor, which causes a risk to the motor.
3.5 Operation against a throttled discharge valve
If the pump set is to be operated against a throttled discharge valve for a prolonged
period of time, the minimum rate of flow should be at least 10% of flow at the best
efficiency point * (BEP) of the characteristic curve, this must be observed in order to
reduce noisy operation and the overheating of the pump set.
* For best efficiency point (BEP) of the characteristic curve consult with KSB dealer.
MULTIBOOST
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