KSB Amarex N series, Installation And Operating Manual

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5 Installation at Site
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Amarex N
2563.84/08-EN
Automatic operation of the pump set in a tank requires the use of level control
equipment.
Observe the minimum level of fluid handled. (
ð
Section 6.2.4.2, Page 39)
5.4.1.3 Operation on a frequency inverter
The pump set is driven by an induction machine to IEC 60034-12 designed for fixed
speed operation. In accordance with IEC 60034-25, section 18, the pump set is
suitable for operation on a frequency inverter.
DANGER
Operation outside the permitted frequency range
Explosion hazard!
▷ Never operate an explosion-proof pump set outside the specified range.
NOTE
The motors can also be operated on frequency inverters. Make sure to observe the
design data of the motor in this case. To prevent an inadmissible heat build-up in
the motor, motors operated on frequency inverters must always be equipped with
bimetal switches in the stator. When reaching the temperature limit, the motor
must be cut out by means of a tripping unit for the equipment to comply with the
ATEX 100a Directive. This tripping unit shall be connected to the measuring points
provided to ensure the temperature class stipulated is observed.
DANGER
Incorrect selection and setting of the frequency inverter
Explosion hazard!
▷ Observe the following information on selecting and setting a frequency
inverter.
Selection When selecting a frequency inverter, check the following details:
▪ Data provided by the manufacturer
▪ Electrical data of the pump set, particularly the rated current
▪ Only voltage source inverters (VSI) with pulse width modulation (PWM) and
carrier frequencies between 1 and 16 kHz are suitable.
Setting Observe the following instructions for setting a frequency inverter:
▪
Set the current limit to max. 1.2 times the rated current. The rated current is
indicated on the name plate.
Start-up Observe the following instructions for starting the frequency inverter:
▪
Ensure short start ramps (maximum 5 seconds).
▪ Only start variable speed control after 2 minutes at the earliest.
Pump start-up with long start ramps and low frequency may cause clogging.
Operation Observe the following limits during operation on a frequency inverter:
▪ Only utilise up to 95 % of the rated power P
2
indicated on the name plate.
▪
Frequency range 30 to 50 Hz
Electromagnetic
compatibility
Operation on a frequency inverter produces interference emissions whose level varies
depending on the inverter used (type, interference suppression, make). To prevent
the drive system, consisting of a submersible motor and a frequency inverter, from
exceeding any given limits always observe the EMC information provided by the
inverter manufacturer. If the inverter manufacturer recommends a shielded power
cable, make sure to use a submersible motor pump with shielded power cables.
Interference immunity The submersible motor pump generally meets interference immunity requirements.
For monitoring the sensors installed the operator must ensure sufficient interference
immunity by appropriately selecting and laying the power cables in the plant. No