Proper Motor Cooling; Providing A Check Valve And Level Sensor; Switching On The Motor; Motor Operation With A Frequency Converter - Franklin Electric 264 Serie Manuel D'installation Et D'utilisation

MOTOR OPERATION

Proper Motor Cooling

Proper Motor Cooling
Motor cooling is provided by water flowing over the motor surface. The cooling efficiency depends
on the water temperature and how fast it flows over the surface of the motor. Inadequate cooling
(the inlet opening of the well is located above the motor or if using a large-diameter well) can
cause damage to the motor and the motor cable.
Installations where the water has a high temperature may require the use of a Flow Inducer Sleeve
to improve cooling. Refer to the Franklin Electric AIM Manual for information about Flow Inducer
Sleeves.

Providing a Check Valve and Level Sensor

Provide one spring-loaded check valve in the production tube in case no such check valve has
been fitted in the pump.
Ensure that the check valve is no further than 7 meters away from the pump.
Install a level sensor for wells with a highly varying water inflow.

Switching on the Motor

Ensure that all steps of the previous section have been carried out properly.
1. Switch on the motor using the mains switch in the control cabinet.
2. Measure the following values after switching on:
• Motor operating current in every phase
• Mains voltage when motor is running
• Level of the medium to be transported
Immediately switch off the motor if:
• the nominal current as specified on the type plate is exceeded,
• voltage tolerances of more than, 50Hz: -10% to +6%/ 60Hz: ± 10%, relative to the nominal
voltage are measured on the motor,
• there is a risk of the motor running dry,
• motor current deviates from the mean value of all three currents by more than 5%.

Motor Operation with a Frequency Converter

NOTE:
When operating a motor with a frequency converter, the relevant operating manual must be
observed!
Make sure that the motor current in all operating levels of the regulating range does not exceed the nominal
motor current indicated on the type plate.
Adjust the frequency converter so that the limit values for the nominal motor frequency of min. 30 Hz and
max. the value of the nominal motor frequency (50 or 60 Hz) are observed.
Limit any voltage peaks on the motor when using a frequency converter to the following values:
max. voltage rise 500 V/μs, max. voltage peak 1000 V.
Make sure that the running up time from 0 to 30 Hz and the deceleration time from 30 to 0 Hz is maximum
one second.
Dimension the cable such that power loss due to additional filters is taken into consideration.
Make sure that the required coolant flow speed along the motor is also observed with frequency converter
operation.
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