Practicing a Consumer Unit install

[scousespark]

Hi @scousespark, let me firstly state that I am grateful for the advice that you and others have provided over the years. I wanted to dispel this impression that I may be some bumbling bafoon that has no regard for safety. Quite the opposite. I am diligent in my safe isolation and ensuring that I have the correct equipment. I have now done a substantial amount with electrics over the years and have felt increasingly confident - but not complacent - as I have progressed. Again, thanks to a huge amount that I have picked up on here.
I am also one to research extensively. Often what I post or receive on here will be triangulated with other research and I will then subject it to my only experimentation - with safety at the forefront of course. The Consumer Unit is one such example. I didn't want to delve into my own consumer unit and hence set up this test rig which has really cemented my understanding. The open CU picture you referred to, allowed me to see where we have live parts in the CU, which is something I set out to understand.
Having said that, I am a DIY'er and there is much to learn. I wanted to share my perspective.

Thanks again for your support

You are missing my point. I'm not saying you are a bumbling buffoon. i am advising you learn the basic theory and principles before you jump in. You hve posted a few questions recently and most fairly basic (how do we cut thick cable, fit capping). Some are basic wiring questions (how does 2-way switching work, fit cabinet lights). These were easy to answer, but stepping up from where to fitting a CU is too much of a stretch for you just now. If you look at it, all you are doing is connecting 2 ends of the cable. You strip the sheath further in the CU.

Saying you worked live to see what went on inside the CU is scary. We have regulations which restrict working live to situations where there is no choice. In most cases an electrician will only work live when testing. Imagine you switch off the light and you get a phone call followed by a knock at the door. You then make a coffee and go back to your rig. You forget the CU is live and reach and touch the busbar. What do you think would happen? You mention Safe Isolation, but appear to not be following the process.

As for gaining knowledge, you should look up Donald Rumsfeld. He quoted " we know what we know, we know what we don't know, we don't know what we don't know about" (not exact quote). To illustrate. You KNOW the brown conductors go into the NCB. You KNOW you don't understand how RCDs work. You DON'T Know that there are a set of tests to run before energising circuits.

Hope this helps.

 

[Jupiter01]

In most cases an electrician will only work live when testing

That is what I was doing.
For all other work, I would de-energise circuits, test and then proceed with the work.

 

[Jupiter01]

You hve posted a few questions recently and most fairly basic (how do we cut thick cable, fit capping)

You say fairly basic questions but as I recall it, both posts generated a different set of views. That doesn't mean that some of the respondents know the basics and others don't. I hear your caution and will heed it but i honestly don't think that I am out of my depth or reckless in any way. Again, my basic questions might be a gap in my understanding or reading that I am looking to clarify. I'm not being defensive either. Sorry if it appears that way.

 

[Taylortwocities]

For all other work, I would de-energise circuits, test and then proceed with the work.

What tests would you expect to carry out, before applying power to a circuit?

 

[Jupiter01]

What tests would you expect to carry out, before applying power to a circuit?

Trick question?
I would have gone through the safe isolation to deenergise the circuit and ensure it is safe to work on. Carried out the maintenance and then energised. I would probably do some more testing at this point. I suppose it depends on the nature of the maintenance.
Over to you.

 

[SUNRAY]

A very big problem we see in this forum is members coming on here and asking questions which prove instantly they are are in well over their head (Usually we see that instantly) and often once the damage has been done, the classic being replacing a light fitting or light switch but not noting what wire went where, and they have absolutely no test kit and don't understand when we suggest something simple (such as "move the red wire from L2 to L1) and they often argue we are incorrect!.

Now at that point I've struggled with colleagues who are in that category and one by one people within the company refuse to work with them. I could give several examples

I have no problem with helping with advice but like most others there is a limit to the extent I'll go to.

I don't understand people telling you how to reconfigure your CU when you are so far from ready to work in a CU.

I totally agree with you SS and similar has already been said, however if you have been following J1's posts itcan be seen this is one of those situations where 'it's going to happen anyway' so our best thing is to help rather than say 'don't'.

I've mentally noted a number of regulars who have opted to not offer advice, which is I assume because they agree too.

Simply put; some on here are thinking you are in the category of 'not ready' and are genuinly concerned about your ability, particularly for your safety. What I see is someone who believes they have more ability than they actually have, I believe you are nowhere near ready/competent/confident to be playing with CU's...

As others have posted; other questions you've asked are far from what we'd expect from someone who is confident/competent to do electrical work. However I can tell (just as others can) that you would not take that advice from us and therefore we plunder on with help in a bid to stop you hurting yourself.

With this fairly long winded (I hope constructive) criticism my final comment is the quality of the work I see on your test board is quite reasonable and it would be remiss of me to not add that I've seen a lot worse done by expert/qualified personel. What I think you are ready for is contact your local college to see what courses would be beneficial to you.

 

[Taylortwocities]

Trick question?
I would have gone through the safe isolation to deenergise the circuit and ensure it is safe to work on. Carried out the maintenance and then energised. I would probably do some more testing at this point. I suppose it depends on the nature of the maintenance.
Over to you.

Not a trick question. I was referring to this task of the new circuits that you are installing for this test consumer unit. And the CU itself.
It isn’t just a case of running the cables and switching on and seeing if the light comes on or not.
The on site guide ( got a copy yet?) will guide you through the “dead” tests which include continuity, R1+R2, polarity, insulation resistance (got a tester?) and others.
Then, after energising, there are more tests that you need equipment and knowledge about. RCD tester, loop impedance tester etc.
it’s all part of the essentials of electrical installation work.

 

[Jupiter01]

@Taylortwocities a kind soul on this forum has offered to send me a copy of the on-site guide. Looking forward to it.

A number of you have helped me on this project and I wanted to share a further update with you. I pulled everything apart today, in an attempt to tidy up the cabling. A slight improvement I think?

I also added in the RCBO and some extra breakers.

Thanks again.