Correcting For Three-Phase Power Imbalance; Developing The Well; Operation; Minimum Flow Rate - Grundfos SP Instrucciones De Instalación Y Funcionamiento

To determine the percentage of current
imbalance:
1. Measure and record current readings in
amps for each leg (hookup 1).
Disconnect power.
2. Shift or roll the motor leads from left to right
so the submersible drop cable lead that was
on terminal 1 is now on 2, lead on 2 is now
on 3, and lead on 3 is now on 1 (hookup 2).
Rolling the motor leads in this manner will
not reverse the motor rotation. Start the
pump, measure and record current reading
on each leg. Disconnect power.
3. Again shift submersible drop cable leads
from left to right so the lead on terminal 1
goes to 2, 2 to 3 and 3 to 1 (hookup 3).
Start pump, measure and record current
reading on each leg. Disconnect power.
4. Add the values for each hookup.
5. Divide the total by 3 to obtain the average.
6. Compare each single leg reading from the
average to obtain the greatest amp
difference from the average.
7. Divide this difference by the average to
obtain the percentage of imbalance.
Use the wiring hookup which provides
the lowest percentage of imbalance.
See section 10.7.4 Correcting for three-phase
power imbalance on page
example of correcting for three-phase current
imbalance.

7.1.3 Developing the well

After proper rotation and current imbalance have
been checked, start the pump and let it operate
until the water runs clear of sand, silt and other
impurities.
Slowly open the valve in small increments as the
water clears until the desired flow rate is
reached. Do not operate the pump beyond its
maximum flow rating. The pump should not be
stopped until the water runs clear.
If the water is clean and clear when the pump is
first started, the valve should still be slowly
opened until the desired flow rate is reached.
As the valve is being opened, the drawdown
should be checked to ensure the pump is always
submerged. The dynamic water level should
always be more than 3 feet (0.9 m) above the
suction interconnector of the pump.
Disconnect the temporary piping arrangements
and complete the final piping connections.
16
30 for a specific
Warning
Under no circumstances should
the pump be operated for any
prolonged period of time with the
discharge valve closed. This can
Caution
result in motor and pump damage
due to overheating. A properly
sized relief valve should be
installed at the well head to prevent
the pump from running against a
closed valve.
Start the pump and test the system. Check and
record the voltage and current draw on each
motor lead.

8. Operation

The pump and system should be periodically
checked for water quantity, pressure, drawdown,
periods of cycling and operation of controls.
If the pump fails to operate, or there is a loss of
performance, refer to section
on page 17.

8.1 Minimum flow rate

To ensure the necessary cooling of the motor,
the pump flow rate should never be set so low
that the cooling requirements specified in
section 6.2.2 Pumped liquids
be met.

8.1.1 Frequency of starts and stops

Motor type Number of starts
Minimum 1 per year is
recommended.
MS 402
Maximum 100 per hour.
Maximum 300 per day.
Minimum 1 per year is
recommended.
MS 4000
Maximum 100 per hour.
Maximum 300 per day.
Minimum 1 per year is
recommended.
MS6
Maximum 30 per hour.
Maximum 300 per day.
Minimum 1 per year is
recommended.
MS 6000
Maximum 30 per hour.
Maximum 300 per day.
Minimum 1 per year is
recommended.
MMS 6000
Maximum 15 per hour.
Maximum 360 per day.
Minimum 1 per year is
recommended.
MMS 8000
Maximum 10 per hour.
Maximum 240 per day.
Minimum 1 per year is
recommended.
MMS 10000
Maximum 8 per hour.
Maximum 190 per day.
9. Troubleshooting
on page 6 cannot