110v transformer wiring

So that if you get a shock between one of the wires and earth you only end up with 55v going through you.

on 28/04/2006, David G supposed :

That is because the centre tap of the 110v side is earthed to the 240v earth :-)

The idea is that there should be a maximum voltage to earth of 55v, which is half of the 110v voltage of the secondary winding.

I have been playing around with a Tool Transformer for 110v power tools. Using an earth leak tester I found that the earth pin on the 240 side gave a reading on earth, neutral and live on the 110v side. I assume this is the centre tapped earth, but am curious to know why this is so.

Might make sense if you read the thread before posting the same thing again.

With earth connected to the centre tap of the 110v side, you only have

AWEM

Thanks for the reply. I am curious to know why it is done like this

|In article , |andrew@no_spam_please_mawson.org.uk says... |> |> With earth connected to the centre tap of the 110v side, you only have |> 55v from either live pin to a potential fault so even if a live wire |> is touched the shock will be minimal |> |> | |Thanks for the reply. I am curious to know why it is done like this

I kills fewer Builders than other ways.

Builders are often soaking wet, and standing in a puddle so reducing the voltage between a tool which they may be holding, and may develop a short to frame, and earth is A Good Thing.

I apologise for the double posting. My origninal and all replies have not shown up in my newsreader. Don't what is going wrong. Had to find the replies through Google Groups. I am using Thunderbird and have never had problems with it. I found an old copy of Gravity and that picks up the messages correctly. Don't know what is going wrong. There are no filters enabled but I do see that other headers are missing.

Anyone any ideas on what is wrong please

Regards

David

With Thunderbird, make sure that the View selector is showing 'ALL', instead of 'UNREAD'?

Thanks for the replies - that gives me a better understanding of the workings.

I meant to reply earlier but have been unable to see the replies until now - my fault with my setup.

Regards

David

Thanks

The fault was with my setup - the account was corrupt. When I changed news served I just changed the name and server of an existing account to save having to reload all the other groups. Thought it was working ok until this fault showed up. Having setup a new account it seems ok now.