Sites using generators, take note!
28 January 2025Although electrical systems are often expressed in simple language as three-phase, neutral, earth, they contain many dynamics and unknowns.
At the entrance to a normal building, there are R, S, T phases and operational grounding (neutral) and protective grounding (earth), and while machines use three phases and earth, homes and offices may use single phase neutral and earth.
The reason why neutral is often not used in machines is that the three phases are balanced and, vectorially speaking, there is no need for balancing power.
In homes and offices, the situation is the opposite. Since the load drawn from each phase can never be the same, the neutral conductor is very valuable…
Neutral Break
In the event of a load imbalance in an electrical system, in the event of a neutral break, looseness or non-contact, disaster is often inevitable.
I hear many people say that we use single phase in homes and offices, if the neutral breaks, there will be no electricity. Of course, if the neutral breaks where the apartment or office receives single-phase electricity, there will be no electricity because the circuit cannot be completed.
However, even if the electricity we use is single-phase, if the neutral breaks at the entrance of the building, our situation depends on probability.
For example, if the neutral breaks at the entrance of a building with 30 flats, depending on the unbalance of the load, the phase-neutral voltage of 20 flats will rise to 300V-400V instead of 220V, and 10 flats will drop to 100V-170V.
If the phase-neutral voltage rises to 300V-400V, your appliances will burn out and your fuse will blow, often after the fire, depending on the appliance burnout.
Residual Current Relay
Again, I get the feeling that many people think that if the neutral is broken, the residual current circuit breaker will open and not allow any damage to the system.
Unfortunately, this is not true. For the residual current relay to open, there must be a leakage, and there is no leakage when the neutral is broken.
On the contrary, there is a catastrophe waiting to happen, which we have begun to hear a lot about: The problem of the conductivity (non-current) of the neutral terminal on the residual current relay!
In other words, the residual current relay; in case of any leakage, the survival measure in the contact of the metal body in case of any leakage, it becomes the main actor of a possible fire that can occur with a lack of contact that can occur in the neutral terminal.
Aladağ Disaster
As a matter of fact, the neutral problem that occurred about 10 hours after the meter change was pointed out in the accident that occurred in the dormitory disaster in the Adana/Aladağ district in November 2016.
Although we cannot claim that the neutral terminal of the meter malfunctioned because there was no meter to examine, the fire that broke out after the meter was changed indicates that the neutral terminal of the meter was either insufficiently tightened or broken.
This fire, which killed 12 people, 11 of whom were young children in the dormitory, should definitely give us an idea of how important the neutral issue is.
What is the Solution?
As a precautionary measure, a surge suppressor is required to enable the residual current relay to trip in the event of a neutral contact or break in devices where the neutral is connected directly to the terminal, especially devices that are replaced daily in buildings and leakage current relays.
The new generation of surge suppressors will also provide comprehensive protection with surge and lightning protection functions, since you cannot activate the residual current relay unless the neutral fault is corrected.
