Originally posted 2017-07-08 15:46:44.
WHAT TO DO WHEN HOME ELECTRICAL APPLIANCES START SHOCKING YOU
It is always a surprise to many people when they just discover that their home electrical appliances which were working perfectly before have started shocking anyone who touches it. Many people had condemned and thrown some of their home appliances as a result of this problem because they immediately attribute the shock to the electrical appliance immediately without any confirmation from an expert.
The most common shocking are the ones coming from our electric cooking stoves especially the type that has a spring heating elements on its surface while the types with black carbon heating element is lesser, another one is the shocking from an electric pressing iron especially when the cloth under it is still wet, even the shocking from water boiling rings not excluded, but the question is how do these electric shocking occur in your home appliances even when there is no sign of wrong connection or electric sparks within the wire connections around the building? What can cause such occurrences? How can I stop and prevent it?
On Saturday night, I returned from a service given to me by someone through this website, the case of this client was a two Storey building located along Aba-Port Harcourt expressway in Port Harcourt city, Rivers state. The whole electrical appliances in the building were shocking such that tenants decided to notify the landlord, who took action by calling an electricians to ratify the problem, though the guy tried his best to trace the source of the fault but because the building was electrified with conduit wiring it became a tedious work for him and anyone around who may try to help in such a situation. According to one of the tenants, who told me that the electrician left the job undone without notifying the landlord; he said that the shocking was not just a minor type rather it comes with full range of voltage as anyone touches any electrical appliances connected to the wall sockets, this has been happening till I came…any way I became glad for the good look I saw on his face in a way of appreciating the fact the situation has been resolved. When someone called me on Saturday morning to know if I have the knowledge of ratifying electrical connections faults in conduit wiring, I was just curious trying to understand what that type of fault could be until we spent 15minutes in a phone call and his address was given to me with agreement to pay for my transportation fees if we are not able to have a good term for my service, I arrived at the location before 12noon that same day, with my electrical wiring tools. To be frank the job will definitely look confusing to any inexperienced electrician because the whole wiring system of the building was covered either with a concrete, block or ceiling so the only visible places in the building was the junction boxes of each section of the building to make it worst there was no color coding in the wiring system. I told the landlord the charges for my service if I eventually fix it, but if I do not; he should just give transport fair to go back which he agreed so to make the story short this is exactly what I did which made go home with a smile that day for situation even the landlord was confused about why the electrician he called could not fix it.
THE PROCEDURES I TOOK:
First I checked the shocking by slightly touching one of the refrigerators connected to the wall socket while the electric power supply is still available and believe me it was not a minor shock because I felt it all over my body, then I asked the tenants to unplug everything connected to the wall sockets and that is where my work began.
CHECKING THE OVERALL JUNCTION BOX
I went immediately and remove the fuse of the line supplying power to the whole building making the building to have no trace of electric voltages, I then opened the major junction box which supplies voltages to the rest of the junctions for distribution in various rooms, and parlors, etc. to trace the fault, but behold nothing visible was found, no trace of burnt wire or sparked edges, so I did check all other junction boxes and yet nothing is indicating any sign of a fault in the wiring as everything in each junction box appeared normal.
DISCONNECTING JUNCTION BOXES
I started disconnecting the junction boxes one after the other to isolate each one from the next linking point for easy testing of any discontinuity, basically I know that such shock may be coming from an earthed wire that has established contact with the live wire in the building but the problem now is how do I identify where this contact has been established.
USING MY DIGITAL OHMMETER
An ohmmeter is an electric device used to measure the resistance of any conductor and it has both the digital type and analog types of it.
I took about 50meters long of small red and black color wire, to fix to the ends the wires in each of the two junction boxes to color code it and identify which one is having discontinuity or contact with the earthed line. This was gradually carried out to about 20 junction boxes in the building and at the end, I was able to detect the point the contact was established not just that I also discovered the causes that led to the melting of the live wire insulator such that it started having direct contact with the uninsulated earthed wire.
It was around 5pm that Saturday that I discovered where the fault was so I immediately started color coding the junction boxes according to meter signal until all the junction boxes were color coded and connected together as it was initially, that took me another one hour.
The faulted junction boxes would be difficult to run wire in them again as wires in the place the contact was established could not be accessed by anyone i.e, it is inside the blocks of the building. So I decided to run a direct surface wire for that very live line to link the two junction boxes while disconnecting the previous live line completely.
TESTING FOR FAULT RATIFICATION
After all the reconnections had been made I returned the building fuse for the public electricity supply and since the power was still available I was able to go through the whole building once again to see that the problem has been ratified.
CHECKING FOR THE CAUSES
I also looked into the possible load that the live wire could carry to generate such heat that could melt its insulator, so I decided to check the two linking junction boxes and the flats they are distributing voltages to; then I discovered that they are supplying to two flats within the area and to one external light located at the front of the building, so a closer look into those flats appliances revealed that the two flats basically make use of two burners high voltage electric cooking stoves along with other electrical appliances, meanwhile the wires used for the whole building were 2mm thick for the supplying junction boxes and 1.5mm for the distributing junction boxes, and I know that if two electric cooking stoves having double burners on them were to be plugged into two different sockets with each two burners switched ON, it simply means that each of the stove would be trying to draw up to 220volts to be able to heat up its heating elements, the same occurs to the other heating stove; hence the junction boxes would be stressed to at least provide 400volts for the two electric cooking stove and if that is the case such voltage is too high for a 1.5mm wire to carry for a long period of time. Imagine if the two flats happen to cook their foods with these stoves simultaneously when power is available up to about 5 hours definitely the wires would be heated up causing the insulators to melt. (Hooke’s law states; that current is directly proportional to heat generated,) think about it.
All I did was to quickly notify to the landlord about my discovery and gave some suggestion on how to curb such situation next time before I left the place.