Inhaltsverzeichnis
Werbung
9. Checking of motor and cable
1. Supply voltage
2. Current consumption
Items 3 and 4: Measurement is not necessary when the supply voltage and the current consumption are normal.
3. Winding resistance
4. Insulation resistance
10. 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 from 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 amps of each phase
while the pump is operating at a con-
stant discharge head (if possible, at
the capacity where the motor is most
heavily loaded).
For maximum operating current,
see nameplate.
Disconnect the submersible drop ca-
ble at the motor starter.
Measure the winding resistance be-
tween the leads of the drop cable.
Disconnect the submersible drop ca-
ble at the motor starter.
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 the
range specified in section 4.1 General .
The motor may burn if there are larger variations in voltage.
Large variations in voltage indicate poor electricity supply,
and the pump should be stopped until the defect has been
remedied.
The difference between the current in the phase with the
highest consumption and the current in the phase with the
lowest consumption should not exceed 5%.
If so, or if the current exceeds the full load current, there are
the following possible faults:
•
The contacts of the motor starter burnt. Replace the con-
tacts.
•
Poor connection in leads, possibly in the cable joint. See
item 3.
•
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 out the pump for overhaul.
•
The resistance value of the motor windings deviates too
much. Move the phases in phase order to a more uniform
load. If this does not help, see item 3.
The difference between the highest and the lowest value
should not exceed 5%.
If the deviation is higher, pull out the pump.
Measure motor, motor cable and drop cable separately, and
repair/replace defective parts.
If the insulation resistance is less than 0.5 M¶, the pump
should be pulled out for motor or cable repair.
Local regulations may specify other values for the insulation
resistance.
Subject to alterations.
87
Werbung
Kapitel
Inhaltsverzeichnis
