Xylem LOWARA e-SV Series, Installation, Operation And Maintenance Manual

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en - Original instructions
e-SV series - Installation, Operation and Maintenance Manual 25
Motor without automatic reset thermal overload protection
1. If the motor is used with full load, then set the value to the nominal current value on the
data plate of the pump unit.
2. If the motor is used with partial load, then set the value of the operating current measured
with a current pincer.
3. For three-phase motors with star-delta starting system, set the thermal relay downstream
of the switching circuit at 58% of the rated or operating current.
4.4.5 Operation with frequency converter
The three-phase motors can be connected to a frequency converter for speed control.

The converter exposes the insulation of the motor to a greater load, determined by the
length of the connecting cable: observe the requirements of the Manufacturer of the
frequency converter

For applications requiring silent operation, install an outlet filter between the motor and
the converter; a sinusoidal filter can reduce the noise even further

The bearings of the motors, from size 315 S/M and up, are exposed to the risk of harmful
currents: use electrically insulated bearings

The conditions of installation must guarantee protection against voltage peaks between the
terminals and/or dV/dt in the table:
Motor size Voltage peak, V dV/dt, V/µs
up to 90R (500 V) > 650 > 2200
from 90R to 180R > 1400 > 4600
over 180R > 1600 > 5200
Otherwise, use a motor with reinforced insulation
3
and a sinusoidal filter.
3
Available on request