Grundfos SP Instrucciones De Instalación Y Funcionamiento página 23

Problem Possible cause/how to check
5. Fuses blow or a)
circuit
breakers trip
b)
c)
d)
e)
High or low voltage.
How to check:
Check voltage at pump control
panel. If not within ± 10 %, check
cable size and length of run to
pump control panel.
Three-phase current imbalance.
How to check:
Check current draw on each lead.
Imbalance must be within ± 5 %.
Control box wiring and
components (single-phase only).
How to check:
Check that control box parts
match the parts list. Check to see
that wiring matches wiring
diagram. Check for loose or
broken wires or terminals.
Defective capacitor (single-phase
only).
How to check:
Turn off power and discharge
capacitor. Check by means of an
ohmmeter (Rx100K). When the
ohmmeter is connected, the
needle should jump forward and
slowly drift back.
Starting relay (certain types of
single-phase only).
How to check:
Check resistance of relay coil by
means of an ohmmeter
(Rx1000K). Check contacts for
wear.
Possible remedy
If cable size is correct, contact power
company. If not, correct and/or replace
as necessary.
If current imbalance is not within
± 5 %, contact power supply company.
Correct as required.
If there is no ohmmeter needle
movement, replace the capacitor.
Replace defective starting relay.
23