Henley block - New Consumer Unit

Discussion in 'Electricians' Talk' started by Wols1991, Apr 18, 2018.

  1. Wols1991

    Wols1991 New Member

    Evening guys,

    I was hopping for some advice.....

    I am needing to fit a new Consumer unit (which will host an RCCB and 32amp MCB for an electric car charge point) - preferably in the existing meter cupboard.....

    I am thinking of using a Henley block.

    Splitting the meter tails into either two single pole Henley Blocks (one for L & one for N) or just a double pole (one row for L the other row for N)

    Q1. Should I split the existing meter tails?

    Q2. Single pole or double pole Henley Block?

    If i don't split the meter tails, how can I go about it?

    Do I take the meter tails from the meter and install into the Henley Blocks then two new meter tails back into the meter, joined into the same Henley Blocks?

    Q3. In regards to the earth, I'm thinking of fitting a 4 way earth block, again, should I split the existing earth into the block and add another earth from the block to the new Consumer unit. Or should I just remove the earth from the fuse and install into a block and then add another earth from the block back into the fuse?

    Please find image below.

    Meter cupboard - Currently

    Thanks alot guys,

  2. Ron12

    Ron12 Member

    You need to get a professional in, electrics can be very dangerous if you don't know what you're doing!
    Risteard and Wols1991 like this.
  3. Bazza

    Bazza Screwfix Select

    With respect

    My first thought is: if you need to ask this, then you should not be doing the work.

    My second thought: the fuse and the (recently installed?) meter are sealed. How do you plan to isolate the supply?

    Third thought: Usually the meter box is reserved for the electricity supplier's equipment.

    Fourth thought: The work you plan is notifiable (new circuit, new consumer unit). Have you raised a building notice with the local authority, or are you a registered electrician?
  4. Wols1991

    Wols1991 New Member

    Hi Bazza,

    I am - the electrician is booked in for a week on Thursday.
    All notifications have been made.

    Ive basically posed the above as this is what the electrician has stated and I wanted to gather some other thoughts.....
  5. Wols1991

    Wols1991 New Member

    Thanks Ron,

    That's exactly what I've done.
    I'm a qualified plumber, so I'm always intrigued when it comes to other trades, especially when it's work carried out on my home.
  6. Bazza

    Bazza Screwfix Select

    Just make sure he is a registered electrician and that he notifies the completed work.
    It’s up to him what type of Henleys he uses, etc.
  7. Wols1991

    Wols1991 New Member

    I think the point is being missed - FYI he's Niceic registered and has been a practicing electrician since the early 80's.

    The electrician will do what he will do, what I am seeking is an open discussion as to how one would do this, personally.

    To clarify I will not be carrying out any work myself.

    As a qualified plumber I have been around electricians in domestic dwellings, complete new builda and very rarely seen somebody split the meter tails and add a new Consumer unit.

    Surely there are some electrically minded people out there who have some thoughts.....
  8. Bazza

    Bazza Screwfix Select

    Mate, you didn't tell us any of this. You said
    This site is visited by many DIYers who plan to do serious electrical work that is way out of their competency level.
    We can usually tell this by the basic questions that they ask, with respect - like yours.
    To me it sounded like you wanted a shopping list and you were off to do it yourself.

    You have a registered NICEIC electrician coming to do the work. How he does it is up to him.

    You'll only pi55 him/her off if you try and impose your ideas on him/her.
    >A bit like you going on site to fit a boiler and the customer tells you how to run the flue, pipes and that plumbering stuff.
  9. Wols1991

    Wols1991 New Member

    Now I have clarified that I will not be doing any of the work myself.
    I also won't be advising somebody with close to 40 years experience.

    It really was just a general enquiry lol.

    Does anybody have an opinion on such work.....

    once again, just in case, it's not 100% clear.

    1. I will not be carrying out the work myself.
    2. I will not be advising a chap who has close to 40 years as a fully qualified electrician.
  10. unphased

    unphased Screwfix Select

    Just to fuel your curiosity, electric car charge points are special cases for electrical requirements. I suspect that the electrician has been asked to install a SEPARATE dedicated one way CU with a 30mA RCD main switch and a 32A supply to the charger. I surmise that he will split the meter tails and run new tails to the new one way CU and reconnect the existing tails to the existing CU. (To be clear, the meter tails are split AFTER the meter else the meter would be bypassed. Your words between Q2 and Q3 in the OP didn't make any sense). To split the meter tails a Henley Block is used. A double Pole is more awkward to wire up because you have one connector block sitting behind the other. Convention is to have the Live at the back and neutral at the front so the live is not exposed when you remove the front cover. Far easier, IMHO, is to use separate single pole Henley Blocks, one for Live, one for Neutral. Much easier to wire and neater to install.
    nigel willson and Wols1991 like this.
  11. Wols1991

    Wols1991 New Member

    Thank you for the thoughts and expertise. It's greatly appreciated.

    1. Mark (electrician) - interestingly prefers double pole, I myself (with zero experience) thought two single poles would be far easier. I guess space in the meter cupboard is limited....

    2. Quite right. A dedicated charging point of course requires RCD protection, so he's opting for a RCCB and then a 32amp MCB. Schneider to be exact.

    3. 6mm ho7 cable for a run of 1.5 meters to the proposed charge point location.

    4. On a side note, there's of course on going debates in regards to a dedicated earth (earth spoke) when it comes to charging points. With the drive recently tarmacked, it's deemed as not ''practical' to carry out installation of an earth spoke.

    5. The earth coming out of the fuse and to the mains consumer unit, would you split this into a 4 way earth block? And take a new earth from this block onto the new 2 way Consumer unit (for the charge point).

    Thanks again for thoughts.
  12. Coloumb

    Coloumb Screwfix Select

    6mm will almost definitely be too small to tap directly off the tails unless you really, really know your onions and have done the maths to prove it's ok and complied with the requirements with the infamous "three meter rule" reg. Whats ho7 cable?
  13. Wols1991

    Wols1991 New Member

    Hi mate,
    Obviously the tails will be 25mm (or I'm sure they will be?!)

    The 6mm ho7 is from the consumer unit to the 7kw charge point. 6mm is adequate over a2m run, surely??

    HO7 is this lovely stuff (better option than SWA, when faced with a clipped direct install - supposedly?) https://www.essentialsupplies.co.uk/acatalog/ho7cable.html
  14. Bazza

    Bazza Screwfix Select

    Earth “spoke” ( :confused: )at the charger end? That means an RCD in the charger. And you’ll also have one at the supply end.

    Do you, sorry I mean your electrician, think that’s a good thing?

    Has anybody made an appointment for the supply to be disconnected and reseller after the work has been done.
  15. Coloumb

    Coloumb Screwfix Select

    Hi "mate", back again? Slow day is it?
  16. Wols1991

    Wols1991 New Member

    Spike* (android autocorrect )

    Mark doesn't have a test box, therefore the only way he can test is with the installation of the RCCB (http://www.rolecserv.com/product/EV-Charging-Test-Equipment)

    Mark sent me a reference to earthing arrangements for a PME system. Therefore, yes a an earth for the electric charge epoint install. "If practical".

    See here - https://www.imageupload.co.uk/image/Eay9

    Again - I won't be carrying out the work and all notifications/pre work has been carried out/booked in.

    Bazza, honestly mate. Enjoy the lovely weather, relax and have an ice cold pint of the good stuff
  17. Wols1991

    Wols1991 New Member

    Ha, I never came onto the forum for anything other than advice / thoughts.

    You asked a question and I replied, there was nothing negative meant by my reply, just so you know.

    I'm chasing up invoices and general admin todyw, so I'm on the laptop all day. If that's a slow day, then yes, absolutely.
  18. Coloumb

    Coloumb Screwfix Select

    Lee - it's you. I can tell it's you.

    1. The name "Lee" in the first post.
    2. The use of "hi mate" in your reply to my post.
    3. The poor spelling.
    4. One minute "not knowing" something, then suddenly "knowing". Look at your response to my 6mm cable point. Only someone with a background in electrics could do this.
    5. Straight in with your passive/agressive routine...

    You asked a question and I replied, there was nothing negative meant by my reply, just so you know.

    I honestly do not have any idea why you keep coming back here? Are you having a competition with someone on scoring troll points on trollsrus.com?
  19. Wols1991

    Wols1991 New Member

    This escalated very quickly
    Honestly, I have no issues in the slightest.

    Working as a plumber for the past 8 years, of course I have an understanding of electrics.
    The initial post surely gives an indication of that.

    If you must know I have completed a 5 days course in testing and inspecting and a 2 week electrical course. Am i an expert, absolutely not..... I never said I was.
    I am around trades people daily, including electricians, so I was hoping to have a good meaningful discussion, providing me with additional opiniknsz other than that of my own.

    Instead, we have got into a conversation about passive aggressive remarks and trolling.

    Unphased' response is exactly what I thought this forum was about. Good honest opinions/expertise.

    I'd rather keep this post dedicated to such people as he, who have nothing negative to say but just relaying, simple, positive thoughts.

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