caprari K+ Serie Manual De Uso Y Mantenimiento página 28

K.M150N.. / K.M100N.. / K.W100N.. / K.D200N.. / K.M200P.. / K.D250P..
18. ELECTRICAL CONNECTIONS
Make sure that the electric control panel corresponds to the national standards currently 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
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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 installer must check that the power supply system is protected against untimely start-up due to the absence of and subsequent
restoring of the power supply.
The electrical connections must be made by qualified personnel, strictly observing all the national installation rules
(in Italy CEI 64-8) and following the wiring diagrams attached to 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, be 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 draw 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 connection changes 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.
The use of INVERTER and SOFT-STARTER if not correctly studied and implemented can be harmful to
the integrity of the pumping group. If the related issues are not known, request assistance from the
Caprari Technical Offices.
Make sure that the cable clamp is tightened. Check that the cable clamp is tightened with an 8 Nm (0.8 Kgm) torque. In case,
for any reason whatsoever, the cable comes free from cable gland, replace the washer and fix the screws before proceeding in
remounting.
If the sheath comes off the cable, check that the joint between the two ends is perfectly insulated and protected against the damp.
The free ends of the cable must never be immersed or wetted in some way. Protect them against water absorption if necessary.
In case of breakage of the power supply cable, the original Caprari spare part must be requested, complete with the cable gland gasket, specifying
in the request the serial number of the electric pump and the number and section of the conductors. Any cable in addition to the standard cable
supplied with the electric pump must have characteristics not less than the latter (contact Caprari S.p.a. and check the type of standard cable in the
sales 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:
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).
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. e V p < 1000 V
750
Caprari S.p.A.