English (GB)
23
8.8 Frequency converter operation
All SL1/SLV pump types are designed for frequency converter
operation to keep the energy consumption at a minimum.
For frequency converter operation, please observe the following
information:
Requirements must be fulfilled.
Recommendations ought to be fulfilled.
Consequences should be considered.
8.8.1 Requirements
• 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 has not been taken into
account. See the frequency converter data sheet regarding the
actual values and the cable influence on the peak voltage and
dU/dt.
• 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/standards must be fulfilled.
8.8.2 Recommendations
Before installing a frequency converter, calculate the lowest
allowable frequency in the installation in order to avoid zero flow.
• Keep the flow velocity above 1 m/sec.
• Let the pump run at rated speed at least once a day in order to
prevent sedimentation in the piping system.
• Do not exceed the frequency indicated on the nameplate.
In this case there is risk of motor overload.
• Keep the motor cable as short as possible. The peak voltage
will increase with the length of the motor cable. See data sheet
for the frequency converter used.
• Use input and output filters on the frequency converter.
See data sheet for the frequency converter used.
• Use screened motor cable if there is a risk that electrical noise
can disturb other electrical equipment. See data sheet for the
frequency converter used.
8.8.3 Consequences
When operating the pump via a frequency converter, please be
aware of these possible consequences:
• The locked-rotor torque will be lower. How much lower will
depend on the frequency converter type. See the installation
and operating instructions for the frequency converter used for
information on the locked-rotor torque available.
• The working condition of bearings and shaft seal may be
affected. The possible effect will depend on the application.
The actual effect cannot be predicted.
• The acoustic noise level may increase. See the installation
and operating instructions for the frequency converter used for
advice as to how to reduce the acoustic noise.
9. Start-up
9.1 General start-up procedure
This procedure applies to new installations as well as after
service inspections if start-up takes place some time after the
pump was placed in the tank.
1. Remove the fuses and check that the impeller can rotate
freely. Turn the impeller by hand.
2. Check the condition of the oil in the oil chamber. See also
section
3. Check that the system, bolts, gaskets, pipework and valves
etc. are in correct condition.
4. Mount the pump in the system.
5. Switch on the power supply.
6. Check whether the monitoring units, if used, are operating
satisfactorily.
7.
For pumps with sensor,
switch on the IO 111 and check that
there are no alarms or warnings. See section
8. Check the setting of air bells, float switches or electrodes.
9. Check the direction of rotation. See section
.
10. Open the isolating valves, if fitted.
11. Check that the liquid level is above the motor for S1 operation
and above the cable entry for S3 operation. See fig. 10. If the
minimum level is not reached do not start the pump.
12. Start the pump and let the pump run briefly, and check if the
liquid level is falling.
13. Observe if the discharge pressure and input current are
normal. If not there might be air trapped inside the pump.
After one week of operation or after replacement of the shaft seal,
check the condition of the oil in the chamber. For pumps without
sensor, this is done by taking a sample of the oil. See section
for procedure.
Every time the pump has been removed from the tank, go through
the above procedure when starting up again.
Maximum repetitive peak
voltage
[V]
Maximum dU/dt
U
N
400 V
[V/
μ
sec.]
850
2000
Warning
Before starting work on the pump, make sure that
the fuses have been removed or the mains switch
has been switched off. It must be ensured that
the power supply cannot be accidentally
switched on.
Make sure that all protective equipment has been
connected correctly.
The pump must not run dry.
Warning
The pump must not be started if the atmosphere
in the tank is potentially explosive.
Warning
It may lead to personal injuries or death to open
the clamp while the pump is operating.
Warning
The impeller can have sharp edges - wear
protective gloves.
Note
Trapped air can be removed from the pump
housing by tilting the pump by means of the
lifting chain when the pump is in operation.
Caution
In case of abnormal noise or vibrations from the
pump, other pump failure or power supply failure
or water supply failure, stop the pump
immediately. Do not attempt to restart the pump
until the cause of the fault has been found and
the fault corrected.
Summary of Contents for SL1.100.100.40.4
Page 39: ...Appendix 39 15 Exploded drawings SLV TM04 2777 2605...
Page 40: ...Appendix 40 SL1 TM04 2778 0904...
Page 41: ...41...
