earth leak

[cdel2005]

my neon screwdriver lights up on all conductive parts on dishwasher should this happen? or is it faulty

cheers

 

[winston1]

Looks as if your dishwasher has no earth. Could be the plug or the feed to the socket.

 

[endecotp]

Probably not, no. Do you have a multimeter?

How accessible is the socket that it's plugged in to? What happens if you plug it in to a different socket? If there is a switch on the socket, what happens when it is turned off?

 

[cdel2005]

yes i have multimeter autorange

what do i do

 

[endecotp]

Unplug the appliance, and measure resistance between the earth pin on the plug and the point on the chassis where you were getting the neon to glow.

 

[ban-all-sheds]

yes i have multimeter autorange

what do i do

Not having a go, just genuinely curious.

Why do you have a multimeter if you don't know how to use it?

 

[ban-all-sheds]

my neon screwdriver lights up on all conductive parts on dishwasher

What prompted you to do that test?

 

[cdel2005]

thanks for the reply's i get 000.4 ohms

 

[ericmark]

It seems as if the socket has a faulty earth, however other things could cause the neon to glow. The Martindale EZ150 socket tester would likely show if the socket is faulty, however not sure if the cheaper versions would. The tester needs a loop test, for it to really test the earth.

To test with a multi-meter is not really good enough to test for earth, however you have already been given one simple test which should show if just one faulty socket or not, and that is to plug it in some where else and see if neon still lights. Even if you need to use an extension lead.

I am personally inclined to recommend you call an electrician, as the tester even the EZ150 is expensive and it can be so many things which cause the neon to glow, even as an electrician I remember a fault like that and the problems I had tracing the cause, it is not unknown for a whole house to be without an earth bond, I remember one house where it was re-wired without there being any power, and the electrician had left the three cables to be connected line, neutral and earth but the DNO had given the house a TT supply so everything bonded but no earth connection. Mistakes can happen.

However also found where one socket was earthed in a kitchen as fed from cooker supply, and all other sockets had lost their earth, odd thing was at first it appeared to be other way around, it seemed that the one good socket was the one at fault. As a result I am loathed to suggest DIY tests as it is so easy to get it wrong and jump to wrong conclusion.

 

[endecotp]

You could try checking resistance from the earth hole of that socket to other things that should be earthed, e.g. other sockets' earths, the screws on sockets and switches, pipes etc.

Or turn off the power and look inside the socket.

 

[EFLImpudence]

If that 0.4Ω is from the plug earth terminal, including the leads, it would appear to be alright.
Touch the leads together and see what the resistance of the leads is and deduct from the 0.4.

Also you can set the meter to V~ and measure the voltage from a known earth (as above) - DW plugged in, of course..
This may not be conclusive depending on the meter but it may help.

 

[winston1]

You could try checking resistance from the earth hole of that socket to other things that should be earthed, e.g. other sockets' earths, the screws on sockets and switches, pipes etc.

Or turn off the power and look inside the socket.

But if the fault is at the MET that would not work correctly.

 

[333rocky333]

As endecotp said, was the washer socket on or off when it lit

 

[ban-all-sheds]

But if the fault is at the MET that would not work correctly.

In what way would it work incorrectly?

 

[Lectrician]

In what way would it work incorrectly?

If the main earth was missing or high resistance.