Electrical Theory Part II

[DarrenSL]

Following on from my last post regarding the electrical conductivity of water, I have another electrical theory question for you (if I may) ...

Very often in films etc. you see people getting electrocuted by appliances falling into the bath water. Would this happen in reality?
Similarly, if I was to be really foolish and take a leaping jump from a pylon onto the electric line I should in theory not be electrocuted, just charged to 400kV!!

 

[gcol]

Some opinions on here.
http://www2.abc.net.au/science/k2/stn/november1999/posts/topic12273.shtm

 

[plugwash]

That thread really sucks and makes some terrible assumptions.

It depends on the appliance and if theres any earthing to the bath.

If the appliance has an earthed metal case enclosing the live parts apart from a few small holes then its unlikely there would be any significiant current in the bath water at all.

if live contacts end up in the water then you could get some nasty current paths in the bathwater. Especially if there is other earthed metalwork in there.

If there is a RCD protecting the system it would probablly trip. Overcurrent probably wouldn't.

 

[DarrenSL]

Ah, sounds like an old and much debated subject. Thanks for that.

Had another thought, once you let go of the wire the body would be charged to 400kv. Possibly, there may be enough current to cause a rather nasty jolt once you landed on the ground.

 

[Spark123]

Had another thought, once you let go of the wire the body would be charged to 400kv. Possibly, there may be enough current to cause a rather nasty jolt once you landed on the ground.

I don't think you will, there is still no complete circuit so current still can't flow, same theory behind birds being able to sit on pylons.

 

[Pensdown]

Similarly, if I was to be really foolish and take a leaping jump from a pylon onto the electric line I should in theory not be electrocuted, just charged to 400kV!!

I'm not sure charged is the correct term but as long as your not earthed you could sit there all day with the sparrows.

There have been quite a few cases where skip lorries have come into contact with overhead lines when loading/unloading. The problem is the driver is often unaware as the tyres act as an insulator. The first the driver knows is when he/she gets out of the cab and completes the circuit to earth.

 

[plugwash]

probablly not with 400KV lines it could happen with LV or MV overheads though............

 

[Pensdown]

There are good examples here

http://www.energynetworks.org.uk/hsg/HSG-Pub-pdfs/LookOutblue.pdf