Single-Phase Connection - Grundfos CR Serie Instrucciones De Instalación Y Funcionamiento

3.2.3 Single-phase connection

Fig. 12 Connection, 220-230 V, 0.37 - 0.75 kW
Fig. 13 Connection, 240 V, 0.37 - 0.75 kW
Fig. 14 Connection, 220-230 V, 1.1 - 2.2 kW
Fig. 15 Connection, 240 V, 1.1 - 2.2 kW
Single-phase Grundfos motors incorporate a thermal
switch and require no additional motor protection.
3.2.4 Frequency converter operation
You can use three-phase motors for frequency
convertor operation following the conditions below.
This section applies to motors defined in IEC 60034.
3.2.5 General conditions
Protect all motors used with frequency converters
against voltage peaks and dU/dt according to IEC
60034-17. Grundfos recommends that you use
insulated bearings for motors from frame size 225
(45 kW/2-pole, 30 kW/4-pole and 22 kW/6-pole).
3.2.6 Mains voltage dependent conditions
200-240 V
No output filters are required for frequency converter
operated motors with mains voltages up to 240 V.
380-500 V
For frequency converter operated motors with power
cable length less than 25 m and mains supply up to
460 V, no additional motor protection against voltage
peaks is required. For frequency converter operated
motors with power cable length of more than 25 m or
mains supply higher than 460 V, sine-wave filters are
required.
500 V and higher
Always use sine-wave filters for motors marked with
500 V or higher voltages.
Motors with reinforced insulation can be
supplied as an option. These motors are
according to IEC 60034-25 and therefore
there is no need for sine-wave filters. This
do not eliminate the requirement for
insulated bearings from frame size 225.
Exception
• Protect Grundfos motors types MG 71 and MG
80 (up to 1.1 kW/2-pole and up to 0.75 kW/4-
pole) for supply voltages up to and including 440
V without phase insulation against voltage peaks
above 650 V between the supply terminals.
• If you use MG 71 and MG 80 without phase
insulation for input voltages above 240 V, it
requires that you use sine-wave filters at the
output of the frequency converter.
MG 71 and MG 80 with phase insulation for use with
variable frequency drives are available as standard
products.
Motors supplied by Grundfos
You can connect all three-phase MG motors with
phase insulation to a frequency converter.
Other motor makes than those supplied by
Grundfos
Contact Grundfos or the motor manufacturer.
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