Troubleshooting; The Motor Does Not Start And Makes No Noise; The Motor Does Not Start But Makes Noise; The Motor Turns With Difficulty - Grundfos JP PS Series Installation And Operating Instructions Manual

9. Troubleshooting

9.1 The motor does not start and makes no noise

Cause Power supply failure
Remedy • Check the electrical connections. If the fault is
repeated immediately, this means the motor is
short circuiting.
• Check that the motor is live. If the fault is
repeated immediately, this means that the
motor is short circuiting.
• Check the protection fuses or breakers. If
required, change burnt fuses or switch on
tripped breakers.
• Check that the pressure switch is live. Verify
power at the switch terminals.
• Ensure that the tank pre-loading pressure is
not higher than the minimum value of the
pressure switch. Set the pre-loading pressure
at 2 psi below the minimum value of the
pressure switch.

9.2 The motor does not start but makes noise

Cause Problem with electrical connections or blockage
Remedy • Ensure that the power supply values are the
same as the values on the nameplate. Correct
any errors.
• Ensure that the connections have been made
correctly. Correct any errors.
• Check the condition of the capacitor. Replace
the capacitor.
• Look for possible blockages in the pump or
motor. Remove the blockage.

9.3 The motor turns with difficulty

Cause Insufficient voltage or blockage
Remedy • Check the voltage which may be
insufficient. Correct any errors.
• Check whether any moving parts are scraping
against fixed parts. Eliminate the cause of the
scraping.

9.4 The motor does not stop when the demand for water

has ceased

Cause Problem with the pressure switch
Remedy • Ensure that the value at which the pressure
switch is set to stop the motor is not higher
than the pressure than the pump can generate
(suction + delivery). Set the pressure switch at
a lower pressure.
• Check that the pressure switch contacts move
freely. If not, change the pressure switch.

9.5 The pump does not deliver water

Cause Insufficient intake or priming failure
Remedy • The pump has not been primed correctly.
Repeat the priming procedure.
• The diameter of the intake pipe is
insufficient. Replace the pipe with a larger
diameter one.
• Blocked foot valve. Clean the foot valve.

9.6 The pump does not prime

Cause Air pockets
Remedy • The intake pipe or the foot valve is taking in
air. Correct the problem and prime again.
• The downward slope of the intake pipe favors
the formation of air pockets. Correct the
inclination of the intake pipe.
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