Reverse polarity at socket outlets

[Bradley6969]

Had some line/neutral reverse polarity today at a job instead of tripping RCD/MCB it’s just melted socket outlet how come RCD/MCB didn’t trip? RCD tested fine??

 

[Pete999]

Had some line/neutral reverse polarity today at a job instead of tripping RCD/MCB it’s just melted socket outlet how come RCD/MCB didn’t trip? RCD tested fine??

Did you check the plug? did you check the tightness of the connections in the socket outlet?, did the cables appear burnt?, reversed polarity does not normally cause any trips, any IR testing done????? lots of question I know.

 

[westward10]

Unless there are other factors involved reverse polarity on an ac system should not affect a socket.

 

[mart spark]

No imbalance between line and neutral so rcd doesn't trip. Possible loose termination caused damage at socket outlet so no prolonged overcurrent at mcb so no trip.

 

[Markyd]

This was like this for 5 years and no problems......only showed up when I was doing a quick check on ring using a plug in tester

 

[Bradley6969]

Thanks for that very helpful, possibly loose connection all I can think of, was the socket outlet still being used as normal?

 

[Markyd]

Is that question aimed at me......if so yes the socket was being used as normal...in fact it had an extension lead plugged in with 5 bits of equipment being used

 

[littlespark]

I’d be checking all the other sockets for same.

 

[Markyd]

Have done that of course

 

[Snailspark]

I think with reverse polarity the main problem is with switching - the switch cuts out the live which in this case is the neutral so any devices plugged in would still in effect, live when the socket is switched off (potentially very dangerous)

 

[westward10]

Couple of years ago was testing a new school block, five classes with dado power. Four were fine but one class every socket reversed.

 

[Zerax]

I've come across whole installations that are reversed... and that's how they were from original build.

 

[buzzlightyear]

was the hoover sucking or blowing ,lol.

 

[Risteard]

I think with reverse polarity the main problem is with switching - the switch cuts out the live which in this case is the neutral so any devices plugged in would still in effect, live when the socket is switched off (potentially very dangerous)

With socket-outlets the major issue is that the fuse in the plugtop (there's a word to annoy some!) will be in the neutral conductor rather than the line/phase conductor.

Reverse polarity in a socket-outlet should be regarded as a serious breach of the Wiring Regulations.