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Beware of electrical current!
Incorrectly performed electrical work can result in fatal injury.
This work may only be carried out by a qualified electrician.
5.5. Motor protection
The minimum requirement is a thermal relay / motor protection switch with temperature compensation,
differential triggering and an anti-reactivation device in accordance with VDE 0660 or the appropriate national
regulations. If the machines are connected to electrical systems in which faults frequently occur, we recommend
installing additional protective devices (overvoltage, undervoltage or phase failure relays, lightning protection).
Local and national regulations must be adhered to when connecting the machine.
5.6. Operation with a static frequency converter
The following points must be observed when operating the converter:
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The pump is suitable for operation with the frequency converter according to DIN EN 60034-17.
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Voltage peaks at the motor winding must be avoided and, where appropriate, suitable filters must be
provided in the motor lead.
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The proper grounding of the entire system must be ensured.
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The specifications of the frequency converter manufacturer must be observed.
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Under certain circumstances, a shielded cable is necessary to comply with EMC directives.
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The information sheet "Using HOMA pumps with the frequency converter" must be observed.
5.7. Activation types
Activation types for cables with free ends (without plugs)
Star-delta activation
If the motor protection is installed in the line:
Set the motor protection to 0.58 x the rated current. The maximum start-up time in star-delta mode is 3 seconds. If
the motor protection is not installed in the line, set the motor protection to the rated current when fully loaded.
Starting transformer/soft start
Motor protection should be set to the rated current when fully loaded. At partial load, we recommend that motor
protection is set 5% above the measured current at the operating point. The maximum start-up time at reduced
voltage (approx. 70%) is 3 seconds.
Operation with frequency transformers
The machine can be operated on frequency transformers. Observe chapter 5.6 of this manual.
If the submersible mixers are operated with a frequency converter type HRG185, the evaluation of the PTC
thermistor must be done via a RL94/9/EC function-tested triggering device.
5.7.1. After Start-Up
The rated current is briefly exceeded during the start-up procedure. Once this process has ended, the operating
current should no longer exceed the rated current.
If the motor does not start immediately after the machine is switched on, it must be switched off immediately. The
start pauses specified in the technical data must be adhered to before starting up again. If the fault recurs, the
machine must be switched off again immediately. The machine may only be started again once the fault has been
rectified.
The following items should be monitored:
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Operating voltage (permissible dev/- 5% of the rated voltage)
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Frequency (permissible deviation -2% of the rated frequency)
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Current consumption (permissible deviation between phases is a maximum of 5%)
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Voltage difference between the individual phases (max. 1%)
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Starts and stops per hour (see technical data)
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Minimum water immersion level, level control unit, dry-run protection
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Smooth running
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Check for leaks, if need be, follow the necessary steps as set out in “Maintenance”