Voltage Present on Earth Line

[Wilko]

Hi - out of interest, what earthing system is used in this installation? In my view, you've had a "near miss" at 75 V, indicating a fault is present. So please get an experienced Electrician with test equipment to review it on site. Otherwise may think you've "fixed it" but just left a hazard.

 

[clanky]

Just back. In answer to a lot of the posts, yes it wasnt probably the wisest thing to break the earth to a live con board but i did.

Insulation test showed pretty much infinity with cable disconnected at both ends.

 

[johnduffell]

I don't agree that 75v measured on a high impedence multimeter is a problem in itself. (Aside from the fact that the earth has been disconnected which is a problem)
50v is the limit of touch voltages of supplies of high current, but 75v that causes a tingle could be 1mA or less.
If it's failing ir tests or tripping an RCD, definitely a danger, but if it's just a low current not dangerous as many appliances leak to earth.
Having said all that, to be clear, none of the above detracts from the fact that the supply should be isolated before removing the earth, and the bonding should really be connected at all times especially on a pme system. Oh, and that the op needs someone competent with suitable test equipment

 

[clanky]

Hi - out of interest, what earthing system is used in this installation? In my view, you've had a "near miss" at 75 V, indicating a fault is present. So please get an experienced Electrician with test equipment to review it on site. Otherwise may think you've "fixed it" but just left a hazard.

As per my first post, the fault is with the washing machine and dryer. Both are now unplugged until i can find a reasonable explanation for their behaviour.

 

[clanky]

I don't agree that 75v measured on a high impedence multimeter is a problem in itself. (Aside from the fact that the earth has been disconnected which is a problem)
50v is the limit of touch voltages of supplies of high current, but 75v that causes a tingle could be 1mA or less.
If it's failing ir tests or tripping an RCD, definitely a danger, but if it's just a low current not dangerous as many appliances leak to earth.

Thanks John, i wondered whether this was normal but the fact that indesit always top the tables on fire hazards had me thinking there may be a fault with the machine. For the record, the circuit is on an RCD and has never tripped.

 

[clanky]

Having said all that, to be clear, none of the above detracts from the fact that the supply should be isolated before removing the earth, and the bonding should really be connected at all times especially on a pme system. Oh, and that the op needs someone competent with suitable test equipment

Point taken and as already mentioned, in hindsight it wasnt my finest hour. But, having found the fault, i investigated it as safely as i could. The earths are all now reconnected before anybody asks. Before i contact my electrician, what tests would you recommend be carried out?

 

[Pete999]

What readings did you get on your IR tests?

I deduct from the 2 optimistic tags I have on this, that you don't think, (like I do) that the OP doesn't have any test gear, with no responses from him it's becoming more and more likely.

 

[buzzlightyear]

Just back. In answer to a lot of the posts, yes it wasnt probably the wisest thing to break the earth to a live con board but i did.

you said it .

 

[buzzlightyear]

rule 1 when removing any Earthing from the met (E.G)bonding
isolate the main switch .

 

[johnduffell]

Before i contact my electrician, what tests would you recommend be carried out?

Would be useful to put a clamp meter on the various cpcs to check the leakage. If you have one.
Other than that you could well be chasing a non issue. There's a reason why it's dangerous to have a missing or broken cpc.

 

[Octopus]

I would start with a Zs at the socket for the washing machine .... maybe its not earthed!

 

[davesparks]

Just back. In answer to a lot of the posts, yes it wasnt probably the wisest thing to break the earth to a live con board but i did.

‘Not the wisest thing’ is a significant understatement, you’ve placed your life and the lives of everyone in the property at risk.

Saying that you are surprised that you measured this voltage after disconnecting the earth of an energised installation is like saying you are surprised that you got wet when you jumped into the ocean.

 

[clanky]

‘Not the wisest thing’ is a significant understatement, you’ve placed your life and the lives of everyone in the property at risk.

Saying that you are surprised that you measured this voltage after disconnecting the earth of an energised installation is like saying you are surprised that you got wet when you jumped into the ocean.

Yeah i get it. Thanks for pointing it out (again) and just to clarify, im not so bloody minded as to place other peoples lives at risk.

Im well aware what i was doing wasnt within the best safety guidelines but moving on, i was rather hoping that i could turn the discussion to the fact i have two appliances that in my opinion are putting excessive leakage voltage onto the cpc. Other than repeating whats already been said, has anybody got anything to add?

 

[Pete999]

A down right rude non response from the OP totally ignored a sensible question regarding IR results, he said he had conducted, makes you wonder sometimes, still he reckons he is sorted, so all's well that ends well I hope.

 

[Pete999]

Yeah i get it. Thanks for pointing it out (again) and just to clarify, im not so bloody minded as to place other peoples lives at risk.

Im well aware what i was doing wasnt within the best safety guidelines but moving on, i was rather hoping that i could turn the discussion to the fact i have two appliances that in my opinion are putting excessive leakage voltage onto the cpc. Other than repeating whats already been said, has anybody got anything to add?

Someone else who has had the profile blocked, what occurring Mods?