Troubleshooting Chart - Grundfos SP Serie Instrucciones De Instalación Y Operación

9.3 Troubleshooting chart

Problem Possible cause and/or how to check
1. The pump a)
does not run.
b)
c)
d)
e)
f)
g)
28
There is no power at the pump
control panel.
How to check:
Check for voltage at the control
panel.
The fuses are blown or the circuit
breakers are tripped.
How to check:
Remove the fuses and check for
continuity with the ohmmeter.
The motor starter overloads are
burnt or have tripped out (three-
phase only).
How to check:
Check for voltage on the line or load
side of the motor starter.
The starter does not energize (three-
phase only).
How to check:
Energize the control circuit and
check for voltage at the holding coil.
The controls are defective.
How to check:
Check all safety and pressure
switches for operation. Inspect
contacts in control devices.
The motor and/or cable are
defective.
How to check:
Turn off the power. Disconnect the
motor leads from the control box.
Measure the lead-to-lead
resistances with the ohmmeter
(Rx1). Measure the lead-to-ground
values with an ohmmeter (Rx100K).
Record the measured values.
The capacitor is defective (single-
phase only).
How to check:
Turn off the power, then the
capacitor. Check with an ohmmeter
(Rx100K). When the meter is
connected, look for the needle to
jump forward and slowly drift back.
Possible remedy
If there is no voltage at the control
panel, check the feeder panel for
tripped circuits.
Replace blown fuses or reset the
circuit breaker. If new fuses blow or
the circuit breaker trips, the
electrical installation and motor
must be checked.
Replace burnt heaters or reset.
Inspect the starter for other
damage. If the heater trips again,
check the supply voltage and the
starter holding coil.
If there is no voltage, check the
control circuit. If there is voltage,
check the holding coil for short
circuits. Replace bad coil.
Replace worn or defective parts.
If an open motor winding or ground
is found, pull the pump from the
well and recheck values at the
surface. Repair or replace the
motor or cable.
If there is no ohmmeter needle
movement, replace the capacitor.