What are the reasons for the double voltage or less voltage in our home and how to prevent it?

What could be the reasons for high voltage surge of 415volt in a single phase load?

The major reason for this is because of the lightning so when it comes in contact with the power wiring, it can cause damage to our electrical equipment in our home. So mostly we do disconnect our electrical appliances from the power or turn them off if there is a chance for lightning because we can save our equipment.

What are the major reasons for the voltage variation in our home?

So as we discussed above lightning strike is a reason and another reason for this is unbalanced load in a transformer. The voltage surge can also be caused by a fault and the lack of a protective device. So for example consider in our home there is no distribution board and the power is supplied from the meter and if the fuse in the meter box is wired heavily then it won’t trip in case of any fault due to the fuse wiring. This could cause the fault current and it will unbalance the system and can cause voltage dip and because of this fault the current consumption would be high, the chances for the damage of the electrical equipments and of the wiring is high too.

The next reason could be the starting or stopping of a heavy load, so in case if there is any industry near to our home and there is heavy machinery that uses high loads to operate and their starting and stopping process could vary the voltage in our home. So in case of starting the large machinery, it would use heavy current and decrease the system voltage, and if this machinery is stopped then there could be a voltage drop. Another reason for the voltage variation is because of the broken neutral, so the electric power reaches to our home with the help of distribution transformer, the R, Y, B will the transformer’s output or it can be called as the three-phase line and this will be connected to the loads and the neutral will be connected. The voltage between the R and the neutral will be 240V and the voltage between phases will be 415.

So the power comes from the transformer through stay wire to the meter, if the stay wire neutral connection is broken, and because of this there won’t be any current in our home, but there would be voltage in the plug point so we would thing that there is current but none of the equipment is working. So during this case take a tester and check the current in meter box check the neutral and phase and if there is current in both then we can confirm that the neutral from the stay wire is broken.

The next situation will be the connection break between the neutral and transformer bush, then-current from Y will travel through R and B according to the load. The neutral could be faulty if the connection from the meter to the distribution board is wrong, if the neutral and phase from the meter to the DB is connected differently then there is a chance for double voltage in one piece of equipment. So to prevent this we can do the color-coding, and we can prevent wire swapping.

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