Pauline

1) AC has a tendency to throw you off
2) DC has a tendency to draw you in

...but don't try it out.

Hi Ray - not according to this source:
http://www.allaboutcircuits.com/

...AC produces extended muscle contraction (tetany), which may freeze the hand to the current's source, prolonging exposure. DC is most likely to cause a single convulsive contraction, which often forces the victim away from the current's source.

Apparently it works like this:

This problem is especially dangerous if the victim contacts an energized conductor with his or her hands. The forearm muscles responsible for bending fingers tend to be better developed than those muscles responsible for extending fingers, and so if both sets of muscles try to contract because of an electric current conducted through the person's arm, the "bending" muscles will win, clenching the fingers into a fist. If the conductor delivering current to the victim faces the palm of his or her hand, this clenching action will force the hand to grasp the wire firmly, thus worsening the situation by securing excellent contact with the wire. The victim will be completely unable to let go of the wire.

Of course - you can't believe everything you read on the interweb.

No doubt there will be no agreement on this then...

Sorry Pauline!

Best wishes.

All I can say is that I have worked in the railway industry for nearly 30 years and all my training and knowledge during that period has been on the basis of my previous post. Not tried it myself, but a colleague who is now a railway trainer told me of a story where he stepped on a DC rail (@400v) and could not free himself, meanwhile a train was fast approaching...he survived.

I should have added that if the back of the hand made contact the power would cause the hand to bounce away instead of grasping the cable.

found this:

Lessons In Electric Circuits, Volume I – DC
By Tony R. Kuphaldt
Fifth Edition, last update October 18, 2006


How AC affects the body depends largely on frequency. Low-frequency (50- to 60-Hz) AC is used in US (60 Hz) and European (50 Hz) households; it can be more dangerous than high-frequency AC and is 3 to 5 times more dangerous than DC of the same voltage and amperage. Low-frequency AC produces extended muscle contraction (tetany), which may freeze the hand to the current’s source, prolonging exposure. DC is most likely to cause a single convulsive contraction, which often forces the victim away from the current’s source.

Thank you to everyone who took the time to respond.

You have confirmed my thoughts that there is a variety of opinions out there. For the purpose of my exam, AC is more dangerous and the individual is far more likely to come into contact with an AC source than a DC source, so that sorts that. I do not supervise electrical work, however obviously I need to raise my knowledge to a level where I have a clear understanding of how it works and its effects.

Having spoken to many individuals, other H&S advisors, senior electricians, lecturers - all with lots of experience and whose opinions I value, I will remain open minded and as they say 'don't try this at home'.

Cheers

Pauline