single phase preventer connection diagram

 

single phase preventer connection diagram

single phasing preventer is used for protection and burnouts of pumps and motors against phase unbalance missing and negative phase sequence all the phases are continuously checked the relay resets automatically and remains off when a voltage is low zero unbalanced or negative phase sequence.

What is Single Phasing?
When a three-phase motor is running, if one phase among three phase open circuited then it is called Single Phasing.
We know that a three-phase motor is more efficient than a single phase motor. Each three-phase motor has either star or either delta connection. So if one of phase is open they will continue to run but they will be drawn approximately 2.5 times the normal current during single phasing condition.
So basically, absent of one phase among the three phases is called Single Phasing.

Why we need Single Phasing Preventer?
You may think that as the motor will continue to run after single phasing, then why we need a Single Phasing Preventer.
We need Single Phasing Preventer because as after single phasing the motor will draw current 2.5 times of the normal current so motor windings may get damaged even may burn.
There are many bad effects of single phasing, so we need a Single Phasing Preventer.


How a Single Phasing Preventer works?
Basically, a Single Phasing Preventer works like a switch, but it automatically closes the circuit in normal condition and opens the circuit in the fault condition that is single phasing.
For better understanding see the below circuit diagrams. There two circuit diagram is given. One diagram for normal condition and other for the fault condition.

 

single phase preventer connection diagram

single phasing preventer is used for protection and burnouts of pumps and motors against phase unbalance missing and negative phase sequence all the phases are continuously checked the relay resets automatically and remains off when a voltage is low zero unbalanced or negative phase sequence.

What is Single Phasing?
When a three-phase motor is running, if one phase among three phase open circuited then it is called Single Phasing.
We know that a three-phase motor is more efficient than a single phase motor. Each three-phase motor has either star or either delta connection. So if one of phase is open they will continue to run but they will be drawn approximately 2.5 times the normal current during single phasing condition.
So basically, absent of one phase among the three phases is called Single Phasing.

Why we need Single Phasing Preventer?
You may think that as the motor will continue to run after single phasing, then why we need a Single Phasing Preventer.
We need Single Phasing Preventer because as after single phasing the motor will draw current 2.5 times of the normal current so motor windings may get damaged even may burn.
There are many bad effects of single phasing, so we need a Single Phasing Preventer.


How a Single Phasing Preventer works?
Basically, a Single Phasing Preventer works like a switch, but it automatically closes the circuit in normal condition and opens the circuit in the fault condition that is single phasing.
For better understanding see the below circuit diagrams. There two circuit diagram is given. One diagram for normal condition and other for the fault condition.