Grundfos SE - Sensors and Protection Devices

SM113 connection diagram
1 2 3 4 5 6 7 8 9 10 11 12 13 14
R1 R2
(92726268)
SM113
TM085735
Standard version Sensor wire 4 - 5 - 6
Sensor version V1 Sensor wire 9 - 10 - 11
Sensor version V2 Built into the motor top
92726268 Resistor kit
Motor wiring diagrams
L1
L2
L3
W
VU
TM082760
Delta connection
L1
L2
L3
W
VU
W
VU
STAR
DELTA
External STAR-DELTA
TM082761
Star-delta connection
Frequency converter operation
CAUTION
Electric shock
Minor or moderate personal injury
‐ Be aware of possible residual voltage
being present.
If the motor is operated by a frequency
converter, the temperature class of the
explosion-proof pumps must be T3.
In principle, all three-phase motors can be connected
to a frequency converter. However, frequency
converter operation often exposes the motor
insulation system to a heavier load and may cause
the motor to be more noisy due to eddy currents
caused by voltage peaks.
Large motors driven with a frequency converter may
be loaded by bearing currents.
For frequency converter operation, observe the
following:
• The thermal protection of the motor must be
connected.
• Peak voltage and dU/dt must be in accordance
with the table below. The values stated are
maximum values supplied to the motor terminals.
The cable influence is not taken into account. See
the frequency converter data sheet regarding the
actual values and the cable influence on the peak
voltage and dU/dt.
• The minimum switching frequency is 2 kHz. The
switching frequency can be variable.
• If the pump is an Ex-approved pump, check if the
Ex certificate of the specific pump allows the use
of a frequency converter.
• Set the frequency converter U/f ratio according to
the motor data.
• Before installing a frequency converter, calculate
the lowest frequency allowed in the installation to
avoid zero flow.
• Do not reduce the motor speed to less than 50 %.
• Keep the flow rate above 1 m/sec.
• Let the pump run at rated speed at least once a
day to prevent sedimentation in the pipe network.
• Do not exceed the frequency indicated on the
nameplate as this may cause motor overload.
• Keep the power cable as short as possible. The
peak voltage increases with the length of the
power cable.
• Use input and output filters on the frequency
converter.
• Use a screened power cable if there is a risk that
electrical noise may disturb other electrical
equipment.
• Set the frequency converter for constant-torque
operation. Use pulse width modulation.
When operating the pump with a frequency converter,
consider the following:
• The locked-rotor torque can be lower depending
on the type of the frequency converter.
• The noise level may increase. See the installation
and operating instructions for the selected
frequency converter.
Maximum repetitive
peak voltage
[V]
Maximum dU/dt U
N
400 V
[V/μ sec.]
2.200 9.000
21
English (GB)