Checking Of Motor And Cable; Disposal - Grundfos BM 4 Instrucciones De Instalación Y Funcionamiento

13. Checking of motor and cable

1. Supply voltage
Voltmeter
2. Current consumption
Ammeter
Items 3 and 4: Measurement not needed if supply voltage and current consumption are normal.
3. Winding resistance
Ohmmeter
4. Insulation resistance
Megohmmeter

14. Disposal

Disposal of this product or parts of it must be carried out accord-
ing to the following guidelines:
1. Use the local public or private waste collection service.
2. In case such waste collection service does not exist or cannot
handle the materials used in the product, please deliver the
product or any hazardous materials form it to your nearest
GRUNDFOS company or service workshop.
Measure the voltage between the
phases by means of a voltmeter.
Connect the voltmeter to the terminals
in the motor starter.
Measure the current of each phase
while the pump is operating at a con-
stant discharge pressure (if possible
at the capacity where the motor is
most heavily loaded).
For normal operating current, see
nameplate.
Remove the phase leads from the ter-
minal box.
Measure the winding resistance as
shown on the drawing.
Remove the phase leads from the ter-
minal box.
Measure the insulation resistance
from each phase to earth (frame).
(Make sure that the earth connection
is made carefully.)
The voltage should, when the motor is loaded, be within
±10% of the rated voltage. The motor may burn if there are
larger variations in voltage.
If the voltage is constantly too high or too low, the motor must
be replaced by one corresponding to the supply voltage.
Large variations in voltage indicate poor electricity supply,
and the pump should be stopped until the defect has been
found.
Resetting of the motor starter may be necessary.
The difference between the current of the phase with the
highest amp consumption and the one with the lowest amp
consumption must not exceed 10% of the lowest amp con-
sumption.
If so, or if the current exceeds the full load current, there are
the following possible faults:
• The contacts of the motor starter are burnt. Replace the
contacts.
• Poor connection in leads, possibly in terminal box.
• Too high or too low supply voltage (see item 1).
• The motor windings are short-circuited or partly disjointed
(see item 3).
• Damaged pump is causing the motor to be overloaded.
Pull the pump out of the sleeve for overhaul.
• The resistance value of the motor windings deviates too
much (three-phase). Move the phases in phase order to a
more uniform load. If this does not help, see item 3.
The highest value must not exceed the lowest value by more
than 5%.
If the deviation is higher, the pump should be pulled out.
Measure motor and cable separately and replace or repair
defective parts.
See section 11. Service manuals.
If the measured insulation resistance is less than 0.5 meg-
ohms and the supply cable is OK, the pump should be pulled
out for motor or cable repair or replacement.
See section 11. Service manuals.
Subject to alterations.
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