One of the most serious electrical faults and perhaps the most serious of all is the disconnection of the main neutral line
in a two- or three-phase system.
When the main neutral conductor disconnects in such connections, an integrated power supply passes through
The single-phase consumers burn most of the single-phase consumers in the facility.
Televisions, computers, lights and more are burning in houses. The damage in such cases reaches thousands of dollars
And also tens of thousands of dollars for facilities, on the other hand, in factories, agriculture, and large businesses the damages
Reach hundreds of thousands of dollars and even millions of dollars.
For example – in a plastic manufacturing plant, the command systems in the machines are burned, not only that the production line is damaged
And the command components need to be replaced and more, the plastic gets stuck in the machines and it takes days to succeed
Clean the machines from the plastic that has dried.
Today it is possible to prevent these damages with a small investment by installing a simple device
An Israeli company called Phasor, the device is called NFPR (neutral failure protection relay)
When the supply of the main neutral is cut off whether by mistake, of electrician’s or for any reason
The NFPR disconnects the power supply to the facility by that it is protecting on the consumers and restores the power supply
automatically after the voltage back to normal (after checking for 10 seconds that the voltage is normal).
It is important to note that the NFPR is not affected by lack of phase!
The NFPR supplies a voltage of 220 VDC to the contactor at point A1/A2 or to the NOVOLT relay and through it to TRIP
COIL or trip coil directly that reacts inversely to lack of voltage (disconnects the breaker when there is no voltage)
As long as one, two or three phases are supplied, the NFPR will output 220 VDC voltage.
In places that prefer to connect the NFPR that will trip the power supply will not automatically return.
If you connect the NFPR through the contactor, the power supply will return automatically when the voltage is back to normal.