Could an unearthed socket in theory cost money?

[DanShepherd]

Ignoring the obvious safety aspects - I finally fixed a socket today in a relatives home where an earth wire had come out of the connector which made the dishwasher, kettle and toaster give them shocks if they didn't have rubber shoes on...great!

Dangerous as that was - these devices appeared to have a current running around their metal parts - which led me to wonder...were they using anything that would register on an electricity meter? Could an "earth leak" so to speak, cost money? Or were they simply conducting through the nearest earth they could find and thus dangerous but "free".

 

[littlespark]

If current flows through the live cable of the supply, the meter will read it. How that current runs back to the supply is immaterial.

Any load on the circuit causes current to flow…. And that load could be a human body.

 

[Mikegh]

Leakage costs money ,so yes

An unearthed socket is less likely to leak and more likely to be dangerous

 

[DanShepherd]

Leakage costs money ,so yes

An unearthed socket is less likely to leak and more likely to be dangerous

So with those metal parts being “conductive” so to speak, it’s more likely just dangerous rather than it was constantly leaking energy?

Are there any tests that can be done for leakage?

 

[pc1966]

Sort of.

While 1mA of leakage (which you would feel as unpleasant) is going to cost around 40p per year if it were "real" power, in most cases such leakage is due to capacitance, so the current and voltage are at 90 deg to each other causing "reactive" power and a true power meter (on that is actually computing the integral of I * V) it would not register as something to pay.

Some larger industrial plants do get charged for reactive power as well as real power, as it impacts on losses in the power generation system, etc, but in those sort of cases 40p per year is not going to be noticed!

 

[pc1966]

As the OP already says, the real "cost" of such a floating earth wire could be someone's life, so important to check and fix!

 

[Mikegh]

So with those metal parts being “conductive” so to speak, it’s more likely just dangerous rather than it was constantly leaking energy?

Yes

Are there any tests that can be done for leakage?

Yes .
Leakage testing ,Pat Testing and EFLI at the outlet would be relevant here anyhow .

 

[timhoward]

I don't think I'm making too many assumptions to say the following.
While reconnecting the socket's earth has provided a 'safe way back' for the current it hasn't addressed why it was there in the first place. The appliances concerned should be PAT tested as mentioned above.
I'd also be interested whether there is an RCD protecting the installation or circuit, my suspicion is that there isn't.
I'd also want to test the circuit to check that if it is designed as a ring final circuit it is still actually a ring.

One possible scenario is that there was a socket with a dislodged earth wire, and the kitchen is wired as either a radial (point to point) circuit or a ring with another break in somewhere else. Either way this leaves a section of the circuit with no path back to earth. Then if an faulty appliance is plugged in within this section, the fault will be felt at that appliance and any others in the section of the circuit that has no path to earth as the metallic outer surfaces are all effectively joined together.

By the way if your relative lives near you I may not be too far away (Oswestry). Message me if you want it looked at.

 

[Lucien Nunes]

But just to clarify for others who read this, the lack of an earth connection definitely will not increase the electricity bill. Leakage occurs naturally, it isn't always indicative of a fault, but how it returns to the source (via the earth connection or via a person) doesn't affect whether it registers on the meter. As Mikegh points out, a disconnected earth can actually reduce the leakage if the appliance is not earthed any otther way.

Much of the 'normal' leakage, i.e. not due to a fault, doesn't register on the meter anyway as it is capacitive and has near zero power factor. For example, a suppressor capacitor in an appliancce that leaks 1mA would create quite a noticeable tingle if you touched the casing in the absence of an earth connection. But at a pf of 0.05 it would register 0.001 * 230 * 0.05 = 0.012W and cost less than 2p per year in wasted energy even if plugged in 24/7.

 

[DanShepherd]

I don't think I'm making too many assumptions to say the following.
While reconnecting the socket's earth has provided a 'safe way back' for the current it hasn't addressed why it was there in the first place. The appliances concerned should be PAT tested as mentioned above.
I'd also be interested whether there is an RCD protecting the installation or circuit, my suspicion is that there isn't.
I'd also want to test the circuit to check that if it is designed as a ring final circuit it is still actually a ring.

One possible scenario is that there was a socket with a dislodged earth wire, and the kitchen is wired as either a radial (point to point) circuit or a ring with another break in somewhere else. Either way this leaves a section of the circuit with no path back to earth. Then if an faulty appliance is plugged in within this section, the fault will be felt at that appliance and any others in the section of the circuit that has no path to earth as the metallic outer surfaces are all effectively joined together.

By the way if your relative lives near you I may not be too far away (Oswestry). Message me if you want it looked at.

Hi Tim,

It was indeed a dislodged earth wire - there is a 2 socket spur coming from the plug which the dishwasher was plugged into.

One of the two earth wires had disconnected from the connector block. Not great as they'd left it that way for YEARS!

Always looking for a reliable local spark though so i'll keep you in mind, doing lots of renovation work myself!

 

[DanShepherd]

But just to clarify for others who read this, the lack of an earth connection definitely will not increase the electricity bill. Leakage occurs naturally, it isn't always indicative of a fault, but how it returns to the source (via the earth connection or via a person) doesn't affect whether it registers on the meter. As Mikegh points out, a disconnected earth can actually reduce the leakage if the appliance is not earthed any otther way.

Much of the 'normal' leakage, i.e. not due to a fault, doesn't register on the meter anyway as it is capacitive and has near zero power factor. For example, a suppressor capacitor in an appliancce that leaks 1mA would create quite a noticeable tingle if you touched the casing in the absence of an earth connection. But at a pf of 0.05 it would register 0.001 * 230 * 0.05 = 0.012W and cost less than 2p per year in wasted energy even if plugged in 24/7.

Thanks - very interesting and all makes sense.

 

[Sparkgap]

But just to clarify for others who read this, the lack of an earth connection definitely will not increase the electricity bill. Leakage occurs naturally, it isn't always indicative of a fault, but how it returns to the source (via the earth connection or via a person) doesn't affect whether it registers on the meter. As Mikegh points out, a disconnected earth can actually reduce the leakage if the appliance is not earthed any otther way.

Much of the 'normal' leakage, i.e. not due to a fault, doesn't register on the meter anyway as it is capacitive and has near zero power factor. For example, a suppressor capacitor in an appliancce that leaks 1mA would create quite a noticeable tingle if you touched the casing in the absence of an earth connection. But at a pf of 0.05 it would register 0.001 * 230 * 0.05 = 0.012W and cost less than 2p per year in wasted energy even if plugged in 24/7.

I find when I use my laptop off the mains (two pin flex into PSU so double insulated, no earth) I get a 'tingle' off the casing of the laptop. Nothing shocking(!) but noticeable if you look for it. I am assuming this is due to some form of capacitive coupling across the PSU leaking voltage through onto the LV side then earthing through my body. The sockets I normally plug into are all on RCDs but I expect as this coupling is not causing current loss from the primary side they would not register this as a fault.

 

[DanShepherd]

I find when I use my laptop off the mains (two pin flex into PSU so double insulated, no earth) I get a 'tingle' off the casing of the laptop. Nothing shocking(!) but noticeable if you look for it. I am assuming this is due to some form of capacitive coupling across the PSU leaking voltage through onto the LV side then earthing through my body. The sockets I normally plug into are all on RCDs but I expect as this coupling is not causing current loss from the primary side they would not register this as a fault.

Yes same, with any unibody Apple laptop. You can touch it with one hand and touch someone else with the other and feel the electricity.

I've had musician friends have trouble with earth loops causing hum and buzz in sound paths because there were too many earths in the loop and often having to remove the earth from the plug itself to stop it.

It's interesting because in the US where it's designed they don't use ground pins - so whilst it's a universal charging adapter it was designed in a country that just uses a 2 pin plug!

 

[Megawatt]

Yes same, with any unibody Apple laptop. You can touch it with one hand and touch someone else with the other and feel the electricity.

I've had musician friends have trouble with earth loops causing hum and buzz in sound paths because there were too many earths in the loop and often having to remove the earth from the plug itself to stop it.

It's interesting because in the US where it's designed they don't use ground pins - so whilst it's a universal charging adapter it was designed in a country that just uses a 2 pin plug!

@ DanShepard yes we do use ground pins. What you are referring to is many many years ago they didn’t have equipment grounds and now I do a lot of work and keep running into this situation and it’s frustrating and yes it’s dangerous.

 

[DanShepherd]

I did an RCA test on the socket this morning and I did trip off at the main switch on the consumer unit. Not sure why the lack of earth wasn't doing that, but it appears to be passing all tests at the moment.

Voltage between Neutral and Earth is reading 00.7v