Reversed polarity.

[dombe]

Just been to a mates flat and he was playing with a socket tester he'd bought.

When he plugged it in it came up with the polarity reversed.

It looks like on the CU the tails are inserted into the wrong holes Black into live and red into neutral.

He's called a mate who is coming to swap them over at the weekend but from what he said its not uncommon, well at least having the polarity wrong. He said they're often connected the wrong way round when big repairs are done to the supply cables in the street.

Is that true? and is it dangerous if it is? I'm surprised his tv and stuff work if its all connected the wrong way round.


Thanks in advance,

 

[plugwash]

reversal in the supply cable is afaict extremely rare in this country due to the use of concentric cables and the general design of the system to support PME.

you need to check if it really is the tails at your CU that are swapped and not a fault further back (in which case you should get onto the leccy board asap).

 

[JohnD]

(A) NO (B) YES

I hope this mate is a competent professional electrician, not an enthusiastic DIYer. It would be a pity if he misdiagnosed the problem and made it worse.

 

[dombe]

He took the cover off and it was plain to see they were in the wrong slots.

He's a diyer but the guy coming to sort it out at the weekend is a registered sparks so will hopefully get to the bottom of it.

Thanks for the replies!