Electrical Connections - caprari K+ Serie Instrucciones De Servicio

18. ELECTRICAL CONNECTIONS

Make sure that the electric control panel corresponds to the national rules in force.
Particularly make sure that its protection degree suits the installation site. It is advisable to install the
electrical equipment in a dry place. Failing this, special versions of the equipment should be used.
ATTENTION The contacts of under-sized or poor quality electrical equipment will quickly deteriorate. This
will lead to an unbalanced power supply for the motor which could damage it. Unless correctly researched
and installed, use of Inverters and Soft-starters can damage the pumping unit. Ask for assistance from the
Caprari Technical Departments if in doubt.
Safe and reliable operation can only be ensured if good quality equipment is installed.
All starting equipment must always be equipped with :
1) a main knife switch with a gap of at least 3 mm between its contacts and an appropriate device to lock it in the open position;
2) a suitable thermic motor protector device calibrated for a maximum power draw no higher than 5% of the current rating indicated on the motor
data plate and with an activation time of less than 30 seconds;
3) a suitable magnetic device to protect the cables against short-circuits;
4) a suitable device to protect the electric pump against earth faults;
5) a suitable phase failure protection device;
6) a device to protect against dry runs;
7) a voltmeter and an amperometer.
The engineer who designs the plant must make sure that the power supply system is protected against unwanted and accidental start-ups due to
the power supply suddenly returning after a blackout.
The electrical connections must be made by qualified personnel in strict compliance with all the national rules of installation (Italy CEI 64-8) and according
to the wiring diagrams enclosed with the control panels. Check that the voltage and frequency values on the electric pump data plate correspond to
those of the electricity main.
ATTENTION If the cables have been disconnected and re-connected, make sure to check the rotation direction again: the phases could have
been reversed. In electric pumps with channel impellers, this would overload the motor and subject it to heavy vibrations of a
hydrodynamic origin. The flow rate would also become much lower than that indicated on the data plate.
Check the power drawn on each phase. Unbalances must not exceed 5%. Higher values could be caused by the motor or the
electricity main. Check the power drawn in the other two motor-main combinations, working with double phase connectionc
hanges in order to maintain the same rotation direction.
The optimum connection is that with the least power draw difference per phase. Note that if the higher power draw is always on the same line phase,
the main cause of this unbalance will be due to the power supply.
For electric pumps K...N1/X1, make sure the cable gland is fastened. If, for any reason, the cable should break free from the cable
gland, before reassembling replace the cable gland gasket and tighten the screw to a torque of 8 Nm (0.8 Kgm). For K...N3 electric
pumps, make sure that the connector is fixed by checking whether the tightening torque of the two screws is 15Nm (1.5Kgm).
If the cable should break its sheath, make sure that the connection between the two ends is perfectly isolated and protected from
humidity.
The free ends of the cable must never be submerged or wet in any way; this being the case, they must be protected from any leaks.
If the power cable gets broken, an original Caprari spare part must be ordered with the cable gland gasket, if any, specifying the electric pump
identification number and the number and section of the conductors in the order. Any additional cable other than the standard cable supplied with
the electric pump must have equivalent or higher characteristics (contact Caprari S.p.A. and check the type of standard cable on the catalogue).
General prescriptions for the use of the INVERTER
- During commissioning and/or use, the minimum frequency must not be lower than 30 Hz, with a steady voltage to frequency ratio
- Maximum acceleration ramp time - 3 seconds
- Maximum deceleration time equal to twice the maximum acceleration time.
- Maximum inverter switching frequency ≤5kHz
Ensure the following operating conditions:
750
Voltage gradient
Conditions that must be met regardless of the length of the power cables.
General prescriptions for the use of the SOFT STARTER:
- The SOFT STARTER device must carry out a voltage ramp starting or a constant current starting
- The SOFT STARTER device must not carry out a current ramp starting or a torque ramp starting
- Minimum peak current Vs = 60% Vn
- Minimum peak current Is = 400% In
- Maximum acceleration ramp time - 3 seconds
- Maximum deceleration time equal to twice the maximum acceleration time
- Deceleration method either by freewheel or by voltage ramp, not by braking
- Always make sure that the soft-starter is off once the assembly start phase has completed.
In case of malfunctioning of a system featuring a soft starter of inverter start, verify, if possible, the operation of the electric pump
assembly by connecting it directly to the grid (or with another device).
Caprari S.p.A.
K.M080.. / K.M100H.. / K.M150L.. / K.W080.. / K.W100L.. / K.T040H.. / K.D200N..+0075..
. e V p < 1000 V
GB
25