Dear, ..........,
Namaskar. Continuing my description of the work in the transmitter centre, I was taking time to master the situation. It is nothing short of a miracle that I remained alive and there was no fatality while I was on duty there. What I mean to say is that the equipment worked on electricity and during its operation, it would generate very high voltage and power. A wrong action could be fatal. There were safeguards like, if anyone would by mistake try to open the equipment door to touch a very high voltage area, the system would trip off a fraction of second earlier to save the person. There would be earth rods too. That is if we need to inspect some component, we would touch it by earth rod first. In case power would be available or be present there, on touching it with an earth rod, it would spark heavily. If no spark, it would mean that the component is safe to touch. I was horrified to see one day during maintenance check that inside the rod the connection to the wire connecting it to earth had snapped. Such a rod would indicate that a particular component did not have electrical charge even if it had charge. Touching that would cause serious injury or death. There were SOP's for maintenance checks and then the status would get recorded in the relevant sheets. But I have seen people sign the sheets without checking the status. There happened an accident that year when I was not on duty. The person died on spot.
Our transmitter had security staff 24x7. They belonged to some para military unit. There were two barracks for their stay adjacent to the transmitter building. Their personnel would be guarding the gate and the entire area. One day, I was on duty in the evening. One of the security staff approached us with a complaint that there was no electricity in their residential unit. I wanted to help them without waiting for the technician to come and attend to the fault. I went to the switch room and got ready to check the fuses. The switch was at a level above my head. I located a stool, propped myself up and switched off the switch. Then I tried to inspect the fuses (it was a three phase switch) The fuses were rotary type and had to be removed by unscrewing by hand. I removed the first one. No problem. Then as soon as I was unscrewing the second one, there was intense sparking from the switch. My face and my right hand on the switch were both in front of the heavy sparking. My eyes got saved because I was wearing glasses. My face got burnt and also the back of my right hand. While all this was happening, I was in control and got down from the stool without falling. I did not get electrocuted. Fortunately the office jeep was there. I was taken to the hospital. They found my face and hand burnt black. The back of my hand had become wet with the burning of fat under the skin. I was in the hospital for a week. Two types of ointment (Ferocin and Phenergan - I remember the names too!!!)were applied on my burnt areas constantly to keep the wounds and skin from getting dry. I had to continue to apply the ointment for another month and then I was declared cured. My original skin tone was returned. Only white burn scars remain on the back of my right hand fingers even today.
Most of the staff felt that it was my fault that caused the sparking. Actually, the switch wiring was such that switching off the supply to this switch would also switch off the power supply to ShortWave transmitter. And secondly, some technician had put some wrong type of wire to short the burnt fuse on a previous occasion. Normally in such type of fuses, when they become bad, have to be replaced. In case a replacement is not available a proper fuse wire has to be soldered properly on the fuse to put the supply through. In this case, the technician had just wound an improper wire (not a fuse wire of proper rating) over the fuse and also not soldered it. When I had rotated the fuse to remove it, the wire had come off and due to its tension one side had accidently touched the power source while the other side had touched the switch body causing the sparking. After the incident, the wiring was modified and strict instructions given to staff not to follow wrong practices. I was wiser after having escaped electrocution or serious injury. The sparks had caused metal resulting from melting of the fuse wire to get embedded in the lens of my spectacles. But eyes were saved.
All my life, I have seen that most of the engineers and technicians do not know what Earthing and Fuse rating means. They ignore it and take it for granting. Even at our homes we are very casual about connecting the power to our domestic appliances. Also we are so casual with fuse rating and replacement. Every one of us should know the significance. I am writing a para here to explain the same as below.
EARTHING: Let us take a heater or an iron. Both are connected to a three pin plug, a three core cable respectively. If the heater is say a 2 Kilowatt rating and the Iron a 1 Kilowatt rating, the wire size would be different. The heater connecting wire would be thicker than the iron connecting wire. One wire in the three core cable would be red coloured. Phase power is supposed to be passing through this cable. The other would be black coloured and this is to be connected to Neutral. The third core is Green coloured and is connected to the the earth terminal. (This is as applied in India. other countries may have other colours) As long as the Heater or the Iron is in very good condition, only Phase and Neutral wire is necessary to make them work. In 220 Volt system, the heater would draw about 9 Amperes current and the Iron about 4.5 Ampere current. In a good wiring system, there would be a MCB (Moulded Circuit Breaker) in the switch for each socket from which power is drawn by the heater and the iron. The MCB for the heater would be 15 Amperes and for the Iron 10 Amperes rating. Now let us imagine that something has happened to both the heater and the iron and the phase wire inside touches the body. The body is already connected to the earth wire. When this happens, the phase gets connected to earth, heavy current will flow and the MCB will trip off. The power supply to the defective heater and the defective iron will get switched off. If we touch these two appliances, there would be no power and we would not get a shock. Therefore all appliances should always remain earthed as a safety measure. (I have seen in some house wiring that the earth wire is not connected properly to the earth, the switch panel and the sockets.) It is therefore always suggested that a good technician should be doing the system wiring as a safety measure. and then we should always connect the appliances properly with the earth wire.
FUSE RATING/REPLACEMENT: Let us go back to the two appliances in the above example. If these appliances are from a good and reputed manufacturers, they would be incorporating a fuse inside the body or the plug. The heater manufacturer will place a 15 Ampere fuse and the iron manufacturer a 10 Ampere fuse inside the appliance. Some have incorporated the fuses in the plug connected to the cable. The fuse here would ensure that it will fuse in case of a fault and ensure safety of the person handling it. It will save the MCB and the house wiring from getting burnt and damaged too. Advice: Never bypass a fuse and replace by an exact replacement and rating.
I am a sweet sixteen aged plus sixty four years of experience as on today. Every year my initial age remains the same while my experience increases by a year. So I thought I should pass my experience to you too. In my later years, I have taught good practices to many of my juniors and seniors have also learned from me. Even if one person who reads this blog gets a benefit, I would be pleased.
Bye.
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