Live to Neutral Continuity on Ring Main on Consumer Unit

[Barry21]

Hi
Have been checking the house wiring on my old wylex consumer board. With the board disconnected and the downstairs power Ring Main disconnected there is continuity between the live and neutral legs. On investigation I found that by disconnecting the Fridge and Freezer from their sockets the problem disappears. I plugged them into the Upstairs Ring Main and the problem moved to the upstairs and disappeared from downstairs. Either of them plugged in and the problem arises again.The other appliances do not throw up this fault. The electrics are working OK and have never had any major problems over the years.
I would be grateful if anyone has any ideas why the fridge/freezer affects the circuit in this way and is it normal.

Thanks

 

[DetlefSchmitz]

All depends on your definition of continuity. Personally I don' think you should be randomly disconnecting things and making random meaningless measurements without some basic understanding of what you are doing or why. It could be dangerous.

 

[PrenticeBoyofDerry]

Do the other appliances have an on/off application?
Did you have the F/F in the off position?
Quite simple open circuit, closed circuit!

 

[ricicle]

What instrument are you using to test. Be careful if it's a multi-function or IR tester as you don't want to be sending 500V along your ring circuits with things plugged in.

Are you competant to be fiddling around in your CU - you don't sound like it

 

[Barry21]

Hi
Using a standard 9volt multimeter. The resistance reading was around 20 Ohms with either freezer/fridge connected and switched on, zero when off.
None of the other appliances in the house have this effect.
Many thanks for your prompt reply's.

Barry21

 

[JohnD]

you should not be testing with appliances connected. It doesn't work that way.

 

[Spark123]

Hi
Using a standard 9volt multimeter. The resistance reading was around 20 Ohms with either freezer/fridge connected and switched on, zero when off.
None of the other appliances in the house have this effect.
Many thanks for your prompt reply's.

Barry21

Shouldn't be zero when off, should be open circuit (out of range on a low range ohm meter usually)
Zero is a short circuit.
Unless you are looking at things with a resistance higher than the range of your multimeter almost all appliances will show resistance across the L-N pins of the plug.

 

[PrenticeBoyofDerry]

Hi
Using a standard 9volt multimeter. The resistance reading was around 20 Ohms with either freezer/fridge connected and switched on, zero when off.
None of the other appliances in the house have this effect.

The microwave will if it does not have an O/I.
It's simple some appliances, need to be manually isolated to create an open circuit between N&L, some don't, such as a standard kettle, toaster as they are self isolation, when water is boiled or bread is browned.
I don't advocate testing whilst appliance are plugged in, as it can give false readings and also lead to high voltages being introduced to them if you forget to unplug whilst IR tests are being made.

 

[Spark123]

Using a DC meter will measure resistance, not impedance hence the readings may appear lower than expected when measuring items with motors in them such as fridges.

 

[ban-all-sheds]

None of the other appliances in the house have this effect.

An appliance which does not show resistance between L & N when on is a broken appliance.

 

[Barry21]

Hi
Thanks to everyone for their reply's, especially PrenticeBoyofDerry who answered my question very much to my liking. I thought I had a major problem on the Ring when my Meter beeped. As explained quite clearly, it is to be expected when an appliance is working correctly and switched on.

Many thanks again, I can sleep peacefully once more.

 

[PrenticeBoyofDerry]

Thanks to everyone for their reply's, especially PrenticeBoyofDerry who answered my question very much to my liking. I thought I had a major problem on the Ring when my Meter beeped. As explained quite clearly, it is to be expected when an appliance is working correctly and switched on.

Happy to help Barry21 and may I add? Welcome to the site and forum!
Before it gets nasty and we all fall out