Unsatisfactory work

[JohnW2]

Thank you John.... When electrician measured the voltage between the appliances it read 230 volts..would that not trip the RCD.

It's not the voltage which matters - it's the current that passes through a person who was simultaneously touching the appliances that would trip an RCD. A domestic RCD will trip with a current between 15 mA and 30 mA. However, even a 15 mA electric shock is a pretty serious one (in terms of 'how it feels') - so if your son only experienced what are usually called 'tingles', it would probably have been considerably less than that.

Can you give us a rough idea of what your son experienced?

Kind Regards, John

 

[akist]

However, even a 15 mA electric shock is a pretty serious one (in terms of 'how it feels')

I seem to recall that 15mA are enough to stop a heart. I definitely would not want to try it regardless how "safe" it may be deemed to be.

 

[JohnW2]

I seem to recall that 15mA are enough to stop a heart. I definitely would not want to try it regardless how "safe" it may be deemed to be.

Even 1 mA is enough to stop the heart in some people. However, for most people it takes more than 30 mA - hence the requirement for 30 mA RCDs.

You are perhaps making the same point that I did to susi1 - that a shock which someone survived which involved sufficient current to trip an RCD would be perceived by the victim as being 'a very severe shock' - which is in a different ballpark from what people often feel when touching non-earthed appliances (which is often just 'unpleasant', as well as frightening).

Kind Regards, John

 

[seasickstevie]

... all these persistent, small electrocutions?

I believe we can be pleased in the fact that no-one's suffered electrocution.

 

[EFLImpudence]

Time is a factor as well.

 

[JohnW2]

Time is a factor as well.

You mean the duration of the shock? If so, then, indeed, very much so.

In fact, many/most of the physiological effects of electric shock are roughly proportional to energy (i.e. the product of power and duration, power being I²R or E²/R) - hence, with all other things being equal, proportional to the duration of the shock. That is, for example, why the (selectable) magnitude of the 'shock' given by a defibrillator is expressed in Joules (i.e. Watts x seconds), not voltage or current.

Kind Regards, John