Grundfos SE1 50 Notice D'installation Et De Fonctionnement page 22

Po
Description
s.
8 Indicator light for leakage (WIO)
9 Indicator light for vibration in the pump
Terminals for measurement of stator
10
insulation resistance
11 Terminals for connection of pump sensors
12 DIP switch for configuration
13 Indicator light for motor temperature
14 Button for resetting alarms
15 Indicator light for motor running
16 Indicator light for service
17 Terminals for digital outputs
Related information
7.1 General startup procedure
10. Fault finding
6.7 Frequency converter operation
If the motor is operated by a frequency
FM
converter, the temperature class of the
explosion-proof pumps must be T3.
All SE1/SEV pump types are designed for
frequency converter operation to keep power
consumption at a minimum.
To avoid sedimentation in the pipes, operate the
speed-controlled pump at a flow rate above 3.28
ft/s (1 m/s).
In this product range, only a negligible amount of
bearing currents occur during frequency converter
operation.
For frequency converter operation, observe the
following:
• Before installing a frequency converter,
calculate the lowest allowable frequency in the
installation to avoid zero flow.
• Do not reduce the motor speed to less than 50
% of the rated speed.
• Keep the flow velocity above 3.2 ft/s (1 m/s).
• Let the pump run at rated speed at least once
a day to prevent sedimentation in the piping
system.
• Do not exceed the frequency indicated on the
nameplate to avoid motor overload.
• Keep the power cable as short as possible.
The peak voltage increases with the length of
the power cable. See the data sheet for the
frequency converter used.
• Use input and output filters on the frequency
converter. See the data sheet for the
frequency converter used.
• Use screened power cable if there is a risk
that electrical noise can disturb other electrical
equipment. See the data sheet for the
frequency converter used.
22
• The thermal protection of the motor must be
connected.
• The minimum switching frequency is 2.5 kHz.
• Variable switching frequency is accepted.
• 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.
Maximum repetitive
peak voltage
[V]
850
• 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.
• Local regulations and standards must be
complied with.
When operating the pump with a frequency
converter, consider the following:
• Set the frequency converter for constant
torque operation. Pulse width modulation
should be used.
• The locked-rotor torque may be lower,
depending on the frequency converter type.
See the installation and operating instructions
for the selected frequency converter.
• Frequency converter use can increase the
wear on the shaft seal and bearings.
• The noise level may increase. See the
installation and operating instructions for the
frequency converter used.
• The working condition of bearings and shaft
seal may be affected.
For further information on pumps
operated with a frequency converter,
visit the Grundfos Product Center at
https://productselection.grundfos.com.
For further information about the frequency
converter operation, see the data sheet and the
installation and operating instructions of
the selected frequency converter.
Maximum dU/dt
U 400 V
N
[V/μ sec.]
2000