Polarity checker

[lydiamight]

After reading some of the various threads about incorrect/reversed mains polarity I would like to be able to check mine. I have a digital mains multimeter and a healthy regard for the dangers of 240volts----how do I actually go about checking if my boat and/or its power supply is wired up correctly?

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[Vara]

Any electrical supplies company.Will sell you a plug in tester.
3 Pin plug with little LEDs on the back,plug in and it tells you whether all is well(or not).
Mine was £14.99 from CEF,but B&Q do them.
Just a thought I 'm not sufficiently techie to know whether a galvanic isolator will effect earth reading?
Have used mine in most marinas South coast UK and North coast France and have not detected any problems.

<hr width=100% size=1>If it can't be fixed with a lump hammer dont fit it!

 

[Bergman]

What you do is measure the voltage between each terminal and earth.

The "live" terminal will show about 230V

The "neutral" terminal will show somewhere between 0 and 10V

If you get 0V on each terminal then check earth connection.

Be careful, live side of mains doesn't give many 2nd chances

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[TonyS]

I am not an electrical expert but I would assume that the live line is at approximately 240 volts to earth and the neutral only a few volts - which you can determine with your mains tester.

Or am I wrong?

<hr width=100% size=1>Tony

 

[paulburton44]

Yes the best way is a plug in checker with 3 l.e.d.'s or neons.
These will tell you correct polarity also if there is an earth and neutral as well.
The approved way of testing is with a neon probe or scewdriver to the live terminal. But that will involve removing a cover etc.

<hr width=100% size=1>www.withamsailingclub.co.uk

 

[Talbot]

Caravan shop should be able to sell you a plug in device that will check the supply coming into the boat. You are responsible for making sure your wiring in the boat is correct.

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[gosh]

My shore supply comes in through into two 13 amp sockets. One is wired correctly and the other with reverse polarity i.e.live is connected to negative terminal. When I plug into shore power I check with a neon tester which socket is putting out the correct polarity and then use that socket to connect to the boat 240V circuit. I use this frequestly in France where they seem to be very cavalier about polarity. A polarity check and polarity changeover switch costs about £150.
Hope that helps.

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[LittleShip]

This is all you need
<A target="_blank" HREF=http://www.tlc-direct.co.uk/Main_Index/Necessities_Index/Ring_Main_Tester/>http://www.tlc-direct.co.uk/Main_Index/Necessities_Index/Ring_Main_Tester/</A>

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I wish I'd been born rich instead of good looking ?