Old Electrical Wiring

[subaqua]

As a start, I would suggest getting a simple socket tester (Screwfix do one for £7.99). This looks like a plug with LEDs in it. You stick it in each socket and the lights and a buzzer tell you whether there are wiring faults, in particular whether there is an earth connection. But the whole thing sounds rather dubious. At the least you will need a new distribution board with RCDs, and plumbing should be bonded to the earth connection at the board (not the same as using the plumbing as the earth connection!).

its OK for a 2week sun spark , but a real spark will use a proper meter to tell him what the actual earth return path value is.

a "socket and see " will work with a return path of several hundred ohms , but for the device to work a 30A rewireable needs a return path of 0.95x2.64 ohms

if the proepr R1 +R2 test and then a measured EFLI gives values under that prescribed in BS7671 then the installation is still safe. there will be recomendations to improve with RCD and split boards to minimise nuisance in the event of a fault on one side but its not a you must .

NEW installations however have a huge amount of items that MUST be fitted. even with the steel conduit in the walls an RCD will be needed as it is a domestic install.

 

[jonesy]

its OK for a 2week sun spark , but a real spark will use a proper meter to tell him what the actual earth return path value is.

a "socket and see " will work with a return path of several hundred ohms , but for the device to work a 30A rewireable needs a return path of 0.95x2.64 ohms

if the proepr R1 +R2 test and then a measured EFLI gives values under that prescribed in BS7671 then the installation is still safe. there will be recomendations to improve with RCD and split boards to minimise nuisance in the event of a fault on one side but its not a you must .

NEW installations however have a huge amount of items that MUST be fitted. even with the steel conduit in the walls an RCD will be needed as it is a domestic install.

Yes, just to be clear, I wasn't suggesting this as an alternative to getting a professional in to do a proper survey. More as a quick check of whether there are any immediate risks. Our predecessors in the house we currently live in had done a lot of DIY wiring over the years, so the first thing we did was have it all properly checked. There is lots of older wiring that wouldn't meet current standards in a new installation, but, as you point out earlier, weren't "illegal" as such. There were also some oddities that actually had one electrician chuckling to himself as he left "Thanks for letting me have a look at this!", but it was still all signed off properly after they had done some alterations we asked for.

 

[subaqua]

Yes, just to be clear, I wasn't suggesting this as an alternative to getting a professional in to do a proper survey. More as a quick check of whether there are any immediate risks. Our predecessors in the house we currently live in had done a lot of DIY wiring over the years, so the first thing we did was have it all properly checked. There is lots of older wiring that wouldn't meet current standards in a new installation, but, as you point out earlier, weren't "illegal" as such. There were also some oddities that actually had one electrician chuckling to himself as he left "Thanks for letting me have a look at this!", but it was still all signed off properly after they had done some alterations we asked for.

yeah first thing I did when I moved in with Mrs Sub 17 years ago was test the electrics . i ended up doing a massive amount of remedial work to gt it close to a safe standard. again mr bodger had lived there earlier. I am now at a stage where all rooms have had the bodges fixed properly and not just on the electrics.

my Mech counterpart who is the gas safe engineer for the company i work for was horrified at some of the pics i showed him of the gas install. he certified remedials on that .

 

[tincaman]

This type of installation is common in industrial premises. If the whole system is metal conduit, then the cables have excellent mechanical protection. The conduit should be bonded at various points, especially at the consumer unit end.
Each socket should have an earth wire from the metal socket across to the face plate, if these are missing they will have to be fitted.
There's nothing wrong with this installation including the red and black wiring, the problems may come later if you have to add anything like extra circuits, your sparks may not have the equipment to fit more conduit.
You can add extra circuits in the normal way with "twin and earth" cable but would need to be careful about where he picked up a new earth from.

 

[sidevalve]

[QUOTE 4168126, member: 9609"]what a load of absolute rubbish, new installations of red black may well be a NO NO, but existing stuff is absolutely fine.[/QUOTE]
As you wish - but if you already know the earth return path why ask anyway ? Second if you wish to 'discuss' the installation with an electrician and appear as though you know what you are talking about I feel you may need a little more study. Any later additions will always look like a bodge and as the wiring is at least [by your own admission] 50 years old why not use the fact to get the price reduced and have it all done new ? I just offered a safe basic solution for future peace of mind and that is all, if you want to call it rubbish why ask ?
Subaqua sort of backs this up in a way - yes the cable may be within it's lifespan but can you be 100% sure there's no damage and yes red/black is ok but there WILL be additions and add ons required and further any 'recommendations' will need to be put right so why not just start from scratch anyway ?

 

[tincaman]

I gotta say that that wasn't what I expected the conduit to look like, it looks like copper, not steel.
You should get high ohm readings between earth and neutral wherever you measure, you are looking for greater than 2 Mohms. Your Sparks can measure the earth continuity to each part of the installation and easily see where the earth path is broken

 

[subaqua]

I gotta say that that wasn't what I expected the conduit to look like, it looks like copper, not steel.
You should get high ohm readings between earth and neutral wherever you measure, you are looking for greater than 2 Mohms. Your Sparks can measure the earth continuity to each part of the installation and easily see where the earth path is broken

That's a pyro (MICC)into the service head by looks of it .

You can get a low N-E reading from any RCD/RCBO on a modern house. It's why we disconnect cables from protective devices when we test.On the suppply side you should , on a TN system have almost dead short N-E as they are connected together at the star point on the distribution transformer.

As for the other post about no fly lead. Not required by BS 7671 if fixed lugs at accessory mounting box .best practice is to fit. GN8 and GN1 have bits on this .

 

[tincaman]

If that's Pyro, from that long ago, I would get it all replaced

 

[subaqua]

If that's Pyro, from that long ago, I would get it all replaced

WHY ? FFS there is nothing wrong with Pyro as an incomer and it is on the DNO side so its unlikely to get changed unless damaged you could try it as a contestable work but don't expect to get far with that option.

where is the meter in relation to the pyro , before or after ?

Good thing about Pyro installs is that not mny sparks have the skill set to do it now as it is no longer on the syllabus as most Fire systems are done in FP200 or Firetuf ( Both cables meet BS8519 )
I have all my pyro kit nicely stored in a toolbox and I get asked quite often to do alterations. last one was re terminating 4 no 1H95 to a generator panel.

 

[subaqua]

yeah thats not gonna get changed until it goes bang ! which will be just after the nuclear holocaust