Frequency Converter Operation - Grundfos AP80-100 Montage- Und Betriebsanleitung

DANGER
Electric shock
Death or serious personal injury
‐
If the power cable is damaged, it must
be replaced by the manufacturer, his
service agent or a similarly qualified
person.
Set the motor-protective circuit breaker to
the rated current of the pump. The rated
current is stated on the nameplate.
Make sure that the pump is connected in
accordance with the instructions of this
booklet.
The supply voltage and frequency are marked on the
nameplate. Make sure the power supply at the
installation site is suitable for the pump motor.
All pumps are supplied with 10 m cable and a free
cable end.
DANGER
Electric shock
Death or serious personal injury
‐
Before the first startup, check the cable
for visible defects to avoid short
circuits.
The pumps must be connected to one of the
following:
• a control unit with motor-protective circuit
breaker, such as Grundfos CU 100
• Grundfos LC 231 or 241 pump controller.
AP80 pumps cannot be operated with
frequency converter.

5.1 Frequency converter operation

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 causes the motor to be more noisy.
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.
• Set the frequency converter U/f ratio according to
the motor data.
• Use a screened power cable if there is a risk that
electrical noise may disturb other electrical
equipment.
When operating the pump by 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
frequency converter of choice.
Maximum repetitive
peak voltage
[V]
850
Frequency converter use may reduce the
life span of the bearings and the shaft
seal, depending on operating mode and
other circumstances.
For more information about the frequency converter
operation, see the data sheet and the installation and
operating instructions for the frequency converter of
choice.
Maximum dU/dt U 400
N
V
[V/μ sec.]
2000
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