shock in stagnant water

Replies

• 

  Ramani Aswath

  It is quivalent to shorting out the 220 V line. . Usually the fuse wiill blow and the line will go dead. If the person touching the water is on dry ground it is likely that no major hazard exists even if the line remains live.
  
  #-Link-Snipped-#
• 

  aswinselva03

  Then what happens if a transmission line is dropped in the stagnant water?
• 

  Ramani Aswath

  aswinselva03

  Then what happens if a transmission line is dropped in the stagnant water?

  The link given earlier covers that situation. If the line does not short out, there could be a real hazard depending on the voltage gradients in the pool. Mineral content of the water and the soil, any free metal pieces lying around can all influence what happens.
  
  In the early seventies I was an eye witness to a sad misadventure that took place during a sharp shower in Bangalore. A street light on a road divider had faulty wiring at the base. It is usual to find grass growing at the base of such posts. There was a sudden shower (not uncommon in Bangalore), which made a puddle a couple of meters from the base. A cow wandered to the grass with its rear legs in the puddle. The moment its nose touched the grass the 220 volts gradient from the post to puddle appeared between its nose and the rear feet. The poor animal went into convulsions and died. The explanation was given by the EE of my lab with sketches later.
• 

  narayana murthy

  aswinselva03

  Then what happens if a transmission line is dropped in the stagnant water?

  simply if we swim on that water we come out as a meat
  and no soul will be inside that body even it carries milli amperes of current as i know even 9ma current is enough to kill a person
  correct me if i am wrong voltage is not a effect on human body only current effects us
• 

  Ramani Aswath

  narayana murthy

  simply if we swim on that water we come out as a meat
  and no soul will be inside that body even it carries milli amperes of current as i know even 9ma current is enough to kill a person
  correct me if i am wrong voltage is not a effect on human body only current effects us

  @nm: You are right.
  However, depending on the body resistance the voltage required to drive even a few microamps through the heart can vary a lot. One can hang from a 110 kv line safely provided the person is far away from the nearest conductor. There is the point where the voltage contacts the body and a point where it leaves. If the heart lies between these two points there is trouble.
  
  The problem is when the current passes through the heart. Few microamps directly through the heart can be fatal, which is why in cardiac and other operation theatres the electrical ground is referred to the patient. The general procedure is to limit the voltage on the body of any equipment in use is not more than 1 millivolt with reference to the patient ground.
• 

  narayana murthy

  bioramani

  @nm: You are right.
  However, depending on the body resistance the voltage required to drive even a few microamps through the heart can vary a lot. One can hang from a 110 kv line safely provided the person is far away from the nearest conductor. There is the point where the voltage contacts the body and a point where it leaves. If the heart lies between these two points there is trouble.
  
  The problem is when the current passes through the heart. Few microamps directly through the heart can be fatal, which is why in cardiac and other operation theatres the electrical ground is referred to the patient. The general procedure is to limit the voltage on the body of any equipment in use is not more than 1 millivolt with reference to the patient ground.

  thanks for the information sir
  from this i known why it is dangerous to us
• 

  Mr.Don

  Thanks for the information sir but we did get some shocks directly from an electronic device which is not fatal. Is this also depend on time we made contact with the shocking device or even some milliseconds is enough to derive the voltage through our body.
• 

  Ramani Aswath

  Mr.Don

  Thanks for the information sir but we did get some shocks directly from an electronic device which is not fatal. Is this also depend on time we made contact with the shocking device or even some milliseconds is enough to derive the voltage through our body.

  I used to work with RF welding of plastics. Once I accidentally touched the live electrode, which was at a high voltage. Even when I pulled away my hand a long lightning life spark continued for almost 10 to 15 cms. To this day I do not know why it did not kill me. May be the radio frequency made the current pass only along my skin to the ground. There were some burn marks on the skin that took long to heal.
  
  You are right in that time of passage of current is a relevant factor.
• 

  narayana murthy

  bioramani

  I used to work with RF welding of plastics. Once I accidentally touched the live electrode, which was at a high voltage. Even when I pulled away my hand a long lightning life spark continued for almost 10 to 15 cms. To this day I do not know why it did not kill me. May be the radio frequency made the current pass only along my skin to the ground. There were some burn marks on the skin that took long to heal.
  
  You are right in that time of passage of current is a relevant factor.

  that was a close one
  sir i think there impedance of our human body saved you
  as bones can act as dielectric at such high voltages and capacitance occured at your body skin
  i think so