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3. The motor should be kept sufficiently cool.
The well should provide with enough water quantity, to ensure max flow which is stipulated on the
rating plate
If the condition and structure of the well cannot ensure the stipulated quantity of water, the
temperature of water in well may exceed 40 °C (104F), you should reduce the load of motor or
increase the gush quantity to prevent over heat of motor.
4. The installation of a non-return valve on the delivery pipe is recommended.
5. Install probes which will cut off the pump power supply before the water level drops to the level
that leaves the pump exposed.
4.3- Electrical connection
4.3.1- Power supply
1. Check the voltage, frequency and intensity of power supply, whether it is according with the
requirements of motor.
2. The voltage of power supply should be (in the case of single-phase voltage) 220-240 V (these are
the permitted limit values), 50-60Hz, the voltage fluctuation is within 0.94-1.06 times the rated value.
3. Avoid contact between the power supply and the liquid to be pumped.
4.3.2- Cable
1. The cable should be suitable for use in water and its size can endure the current of motor.
The cable should comply with the local standards.
In order to keep the line voltage, the length of cable cannot exceed the stipulated length by motor
manufacturer (i.e. < 40m).
2. If the distance to power supply is far, it is recommended to use a bigger diameter cable.
The insulation resistance of motor stator winding should be over 5mega-Ohm.
3. It is first recommended to hang the pump and fixed it firmly, then install a leakage protector at the
end of power cable and finally make earth grounding connection with the ground wire.
The wire identified by the colour combination green/yellow shall be grounded safely to prevent
electric shock (plug marked grounding).
4. Fix the power supply cable to the delivery pipe so that it can not be twisted. Allow for expansion of
the delivery pipe by leaving a little slack between the clamps.
5. When carrying out connections, make sure that there is an efficient earth circuit.
6. The earth wire must be longer than the live wires, and must be the first wire to be connected when
the pump is being set up and the last to be disconnected during disassembly
7. Connect the pump to a socket of 2 poles + earth type of 10-16A/250V, fitted with residual current
device (RCD) or circuit breaker with a sensitivity not exceeding 30mA.
4.4- Control Box
1. Each single phase three wires of the motor should be connected to a control box
2. Check that the data on the rating plate corresponds with the stipulated values.
3. According to the standard, the control box should consist of the capacitor providing single-phase
power, two poles switch and overload cut off protection.
4. Check the electrical equipment installations and control box which should accord with all of the
safety rules and the requirements of motor where included the size of fuse or breaker and over-load
protector, all of metal pipe and control box connected with the earth wire of power supply to prevent
electric shock, should conform to the safety rule of law both of national and regional.
5. If the overload cut-out triggers, check the cause of the overload before restart again.
6. Caution: It is the installer's responsibility to perform the connections in compliance with the
regulation in force in the country of installation.
