My Complete DIY Rewire

[PreferNotToDieOrBurn]

A voltage drop in a junction box means heat is being created in the junction box.

Thank you for this answer - I'll interpret this as meaning there is no voltage drop from a junction box unless it is not wired correctly and is creating heat.

I've managed to eliminate two junction boxes from the design so far. I'm going to keep trying to eliminate more.

Future sockets I will definitely strip more grey insulation as advised. I was trying to leave as much protection as possible. If stripping more grey insulation is the done thing then it makes my life easier too.

Is there anything I've described doing so far, which someone believes may not be to code?

 

[PreferNotToDieOrBurn]

Prerfernottoburn . . . .

As a DIYer who has been in your position and rewired a whole house (including CU) please take notice of the questions you are being asked about testing.

Thank you.

The truth of the matter is I haven't posted the testing I plan on doing myself yet, because I'd rather not feed the negativity. At present the first stage for me will be testing continuity of cable runs before and after each socket is added (R1+R2). I'll probably also do insulation resistance tests myself too.

Any testing from the CU will be carried out by an electrician.

Are there any other test you recommend I carry out prior to the circuits being connected to the CU?

 

[Taylortwocities]

Yes, all of the tests laid out in Guidance Note 3.

 

[PreferNotToDieOrBurn]

Yes, all of the tests laid out in Guidance Note 3.

If I'm not connecting circuits to the CU then there are parts of the system I cannot test, ie. RCD's, EFLI etc

If you could elaborate on which test I could conduct, that would be more helpful than a dismissive blanket statement.

 

[Taylortwocities]

Now we have found the edge of your capability.

How can you install a complete system if you do not even know the basic information about how to test the work.

I could send you a list of the testing requirements, but it would be of little help unless you have a set of calibrated test equipment, and the KNOWLEDGE of how to understand, interpret and act on the results that the test equipment showed you.

Its not a matter of throw in a few wires, and everything must be OK if the lights work and the RCD doesnt trip.

 

[PreferNotToDieOrBurn]

You've found the edge of my experience, yes. I'm holding my hands up high to that. But conversely this isn't rocket science.

I've picked up a Fluke 1652 and a Fluke T5-600.

Taylor do you have a sensible answer? For example "you should really also check xyz before you pass the circuits on to the electrician" rather than "I could tell you but I won't"?

I think at this point everyone including myself agrees I don't have the experience or the knowledge to do a professional job (never debated), however I believe I can complete the work to a satisfactory and safe level which will meet all requirements. It's like fixing a car, same risk, same knowledge needs to be gained, but also not rocket science. In taking care a DIY'er with no experience can come up with a satisfactory result.

By asking questions I'm giving myself the best chance of completing this work. Believe me it's difficult to persevere with all the unhelpful and dismissive comments, but I'm still here because the few helpful nuggets are extremely valuable and I can ignore the superiority complex anti-diy'ers.

 

[Taylortwocities]

OK, like you are fixing your car. You've picked up a socket set.
Maybe you need to get a maintenance manual for the car too?

Look, you are going to install some cable. How do you know the limits of the circuit? Do you know even the characteristics of the supply? You'll need to know the Ze of your supply, so you can add that to the R1+R2 value of the circuit to calculate the Zs.

Then you need to check if the Zs value (don't forget the rule of thumb percentage) is within the limits set out in BS7671 (you do at least have a copy of that?) otherwise your CPD will not trip in the event of a fault.

And if your Zs value is too big, that means you did not design the circuit correctly and you'll need to rip the cable out and install a bigger one.

Got that? Its easy isnt it? But all the above is BASIC electrical installation 101 stuff.

 

[PreferNotToDieOrBurn]

OK, like you are fixing your car. You've picked up a socket set.
Maybe you need to get a maintenance manual for the car too?

Look, you are going to install some cable. How do you know the limits of the circuit? Do you know even the characteristics of the supply? You'll need to know the Ze of your supply, so you can add that to the R1+R2 value of the circuit to calculate the Zs.

Then you need to check if the Zs value (don't forget the rule of thumb percentage) is within the limits set out in BS7671 (you do at least have a copy of that?) otherwise your CPD will not trip in the event of a fault.

And if your Zs value is too big, that means you did not design the circuit correctly and you'll need to rip the cable out and install a bigger one.

Got that? Its easy isnt it? But all the above is BASIC electrical installation 101 stuff.

I do understand that. I'm not testing the Ze myself however I can design the circuits to be safely within margins on R1+R2 (if correctly installed). I've also designed the circuit to allow me to segment one ring main into two if necessary. When the Ze is tested, and added to the R1+R2 and then the Zs is calculated I'm first of all expecting to be well within margins, and secondly I can deal with values outside of regs+margins.

I do have a copy of BS7671, and Brian Scaddan's "17th edition Explained and Illustrated", and "Inspection Testing & Certification", and "Design and Verification" and "Wiring Systems & Fault Finding for Installation Electricians" books. And Darrell Locke's Guide to 17th Edition Wiring Regulations. And Geoffrey Stokes Handbook of Electrical Installation Practice.

In my understanding, simplified, the Zs is likely to be too high in an installation like this if the resistance on the circuit is too high. This means, in my mind, I'll know if I'm well within margin on the Zs if the R1+R2 values are nice and low. And as I said above, the design can be adapted. Further, if the R1+R2 values are high or inconsistent then I know I've messed something up and I need to take another look at my work.

The blind man can navigate a room, he just has to shuffle slowly with his arms out in front of him. That's me in this context.

 

[sparkwright]

Future sockets I will definitely strip more grey insulation as advised. I was trying to leave as much protection as possible. If stripping more grey insulation is the done thing then it makes my life easier too.

What's wrong with correcting the ones you have already done?

A double socket should normally have no more than 10 mm of the grey sheath in the box, and the coloured cores would be around 5 inches long. All wires the same length. All neatly arranged.

Most people here realise you are going to do this work anyway, so most people want you to do a job to professional standards.

How are you stripping the grey sheath off?

Rightly or wrongly, the easiest way is to find the end of the bare earth wire, and pull it so it cuts through the sheath. Like a cheese wire, I suppose.

This way you will get minimum sheath left in the box, which is what you want.

 

[PreferNotToDieOrBurn]

What's wrong with correcting the ones you have already done?

Very good point, I will do that!

Most people here realise you are going to do this work anyway, so most people want you to do a job to professional standards.

Thank you - yes, I'm not going to bore you with the reasons why, but the end result is I am going to do this work one way or another.

How are you stripping the grey sheath off?

I'm using needle nose pliers. I cut a little bit with some nail scissors (by putting one end into the grey insulation slightly) and then roll the grey insulation off with the pliers. Works very well and doesn't damage anything. It's basically what you've suggested but in reverse.

 

[AndyPRK]

I use a sharp blade to cut down the middle (where the earth wire is)
not quite all the way though the grey.

 

[sparkwright]

Of course you're going to get blasted for using nail scissors, as I doubt they are insulated - hopefully I shouldn't have to say any more.

Keep sending pictures - but if there's anything we don't like the look of we will comment, and no doubt expect you to improve on it.

 

[Cabbyfan]

Have to say as someone who served a 4 year apprentiship as an electrician and who now has a B.Eng degree in electronic engineering this thread fills me with horror.

I am currently renovating my house, I'm rewiring it myself but its done via notification to BC with a named local electrical contractor who will do final test and inspection. This is all sanctioned by my building control inspector.

Regardless of having no or a small budget there is no excuse for no grommets on boxes, no conduits or capping on cables, no design or load calcs etc. if this property ever comes up for sale good luck.

MK sockets but can't be bothered or can't afford plastic oval in the walls? Glue to hold cables ???

I'm speechless.

This thread isn't a wind up is it ???

 

[JohnD]

This thread isn't a wind up is it ???

Of course it is

 

[Cabbyfan]

This thread isn't a wind up is it ???

Of course it is

I hope you are right otherwise someone is going to get a nasty shock. Literally.