Electrical Data; Minimum Nominal Flow Rate - Pentair PVM Serie Instrucciones De Funcionamiento

ENGLISH
The net positive suction head required is a function of the
pump design at the operating point on the pump performance
curve.
NPSH =Ha-Hs-Hf-Hv-Hst (in meters head)
A
Ha: Barometric pressure.(That can be set to 10.2 m.)
Hs: Suction lift.
Hf: Friction loss in suction pipe.
Hv = K
+K : Vapor pressure
T H
K
: Pressure reduction due to liquid temperature.
T
K
: Pressure reduction due to elevation above sea level.
H
If the liquid is water, refer to the table below to determine the
values of K and K .
T H
Hst: Safety margin. (minimum: 0.5 meters head)
NPSH > NPSH
: Pump running will be fine.
A R
NPSH < NPSH
: The pump will be dry running or cavitating.
A R
WARNING: Stop operation of the pump if cavitation occurs.
Cavitation will cause pump damage and the resultant damage
is not subject to warranty

4.4 Minimum nominal flow rate

To prevent overheating of the internal pump components, the
pump should not be used at flows below the minimum flow
rate.
WARNING: Do not run the pump against a closed discharge
valve for longer than a few seconds.
The curve below shows the minimum flow rate required as a
percentage of the pump nominal flow rate in relation to the
liquid temperature.
4

4.5 Electrical data

See the motor nameplate.
WARNING: Make sure that the supply voltages, phase and fre-
quencies correspond to the motor specifications.
4.6 Number of starts per hour
Motors up to and including 4 kW: Maximum 100 starts per
hour. Motors of 5.5 kW and up: Maximum 40 starts per hour..
WARNING: If you use another brand of motor then check the
manufacturer's instructions for the maximum frequency of
starts.
5. INSTALLATION
Always refer to the local or national regulations and codes
relating to the selection of the installation site, the water and
power connections, etc.
5.1 Position
Pumps should be installed in a protected environment – not
exposed to weather. Make sure that there are no obstructions
to prevent proper motor cooling.