1
1shortcircuit
Can I request some advice please?
Ordinarily I wouldn't undertake such work but this is for someone I know and they are interested to know the condition of the wiring in a small flat they are about to purchase.
With it only being two circuits I felt happier as I could look at the installation in greater depth within the time allowed. Let me tell you, I don't fancy moving onto anything bigger for a while lol.
Obviously as you do when you walk into something new you find challenges and things that you're not quite sure about so this is where I hope to post my findings and hope that you guys will be kind enough to educate me into understanding how you overcome certain situations.
Now there were no Limitations agreed previously so I checked every single lighting outlet and 85% of the ring final outlets.
The small flat is in a four storey property, basement, ground floor (where the supply incomer is positioned) 1st floor and Top floor (where I was testing)
My first question is, to obtain the Ze (External Earth Fault Loop Impedance) the main earth needs to be disconnected to remove all parallel paths. How is this done when working on flats that are all sharing the same main earth terminal? Surely it's not a case of "Sorry mate, need to switch your electric off", what if they're on life support? Ask them to hold their breath until you're done? lol What if, like in this situation some of the residents are not home?
I took a Zs at the Consumer Unit and obtained a reading of 0.12 ohms, pscc of 3ka and a pefc of 1.8ka
How severe are the consequences if you are seen to be coding on the side of caution?
The condition of the wiring was sound however there were quite a few areas that need attention.
All of the main earth's from each flat join in a Henley block where a 6mm cable passes into the supply head, no idea if there is a link (although I believe from test results this is a TNS supply) and whether the termination is sound?
Any assistance very much appreciated
1SC
Ordinarily I wouldn't undertake such work but this is for someone I know and they are interested to know the condition of the wiring in a small flat they are about to purchase.
With it only being two circuits I felt happier as I could look at the installation in greater depth within the time allowed. Let me tell you, I don't fancy moving onto anything bigger for a while lol.
Obviously as you do when you walk into something new you find challenges and things that you're not quite sure about so this is where I hope to post my findings and hope that you guys will be kind enough to educate me into understanding how you overcome certain situations.
Now there were no Limitations agreed previously so I checked every single lighting outlet and 85% of the ring final outlets.
The small flat is in a four storey property, basement, ground floor (where the supply incomer is positioned) 1st floor and Top floor (where I was testing)
My first question is, to obtain the Ze (External Earth Fault Loop Impedance) the main earth needs to be disconnected to remove all parallel paths. How is this done when working on flats that are all sharing the same main earth terminal? Surely it's not a case of "Sorry mate, need to switch your electric off", what if they're on life support? Ask them to hold their breath until you're done? lol What if, like in this situation some of the residents are not home?
I took a Zs at the Consumer Unit and obtained a reading of 0.12 ohms, pscc of 3ka and a pefc of 1.8ka
How severe are the consequences if you are seen to be coding on the side of caution?
The condition of the wiring was sound however there were quite a few areas that need attention.
All of the main earth's from each flat join in a Henley block where a 6mm cable passes into the supply head, no idea if there is a link (although I believe from test results this is a TNS supply) and whether the termination is sound?
Any assistance very much appreciated
1SC
