Electrical Installation; Supply Cable; Motor Protection; Electrical Connection - Grundfos CM 1 Manual De Instrucciones

7. Electrical installation

Carry out the electrical connection according to local
regulations.
Check that the supply voltage and frequency
correspond to the values stated on the nameplate.
Warning
The electrical connection must be
carried out in accordance with local
regulations.
Before starting work on the pump,
switch off the power supply. Make sure
that the power supply cannot be
accidentally switched on.
The pump must be connected to an
external mains switch with a minimum
contact gap of 3 mm in all poles.

7.1 Supply cable

In order to comply with the EN 60335-1 standard, the
supply cable must as minimum be rated for an
operating temperature of +105 °C (+221 °F).

7.2 Motor protection

Single-phase motors, 1 x 115 / 230 V, 60 Hz
These motors do not incorporate motor protection
and must be connected to a motor-protective circuit
breaker which can be manually reset.
Set the motor-protective circuit breaker according to
the rated current of the motor (I
Other single-phase motors
These motors have built-in current- and
temperature-dependent motor protection in
accordance with IEC 60034-11 and require no further
motor protection. The motor protection is of the
TP 211 type which reacts to both slow- and
quick-rising temperatures. The motor protection is
automatically reset.
Three-phase motors up to 3 kW
These motors must be connected to a
motor-protective circuit breaker which can be
manually reset.
Set the motor-protective circuit breaker according to
the rated current of the motor (I
Three-phase motors of 3 kW and up
These motors have built-in thermistors (PTC)*. The
thermistors are designed according to DIN 44082.
The motor protection is of the TP 211 type which
reacts to both slow- and quick-rising temperatures.
* Applies only to motors for the following supply
voltages:
• 3 x 200 V / 346 V, 50 Hz
• 3 x 200-220 V / 346-380 V, 60 Hz
• 3 x 220-240 V / 380-415 V, 50 Hz.
Motors for other supply voltages must be connected
to a motor-protective circuit breaker as described for
three-phase motors up to 3 kW.
). See nameplate.
1/1
). See nameplate.
1/1

7.3 Electrical connection

Carry out the electrical connection as shown in the
diagram inside the terminal box cover.
Fig. 7 Wiring diagram

7.4 Frequency converter operation

All single- and three-phase motors can be connected
to a frequency converter.
Depending on the frequency converter type, this may
cause increased acoustic noise from the motor.
Furthermore, it may cause the motor to be exposed
to detrimental voltage peaks.
MG 71- and MG 80-based motors have
no phase insulation* and must
Caution
therefore be protected against voltage
peaks higher than 650 V (peak value)
between the supply terminals.
* MG 71- and MG 80-based motors with phase
insulation are available on request.
The above disturbances, i.e. both increased acoustic
noise and detrimental voltage peaks, can be
eliminated by fitting an LC filter between the
frequency converter and the motor.
For further information, please contact the frequency
converter supplier or Grundfos.
Self-priming pumps only:
If the pump is connected to a frequency
converter, operation at low speed may
Note
cause the internal recirculation valve to
open. This will result in a drop in
pressure and flow.
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