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main switch

  1. T

    Removed these from a mains change today

    Evening all Picked out these bad boys from a few board changes the other day. Not sure if they are worth keeping?
  2. C

    Commercial What Cert got fitting main switch

    Hi I have been asked to fit a main switch / isolator by my client as they have no means of isolating the full installation by a single means. So I'm planing on fitting a Wylex isolator like the ones meter people fit but my question is what Cert should I be I fill out at the end a minor works or...
  3. Steve93

    4mm cable into the bottom of main switch.

    Eicr today had a 4mm T+E connected into the bottom of a main switch which went to a separate dB with 1 20amp rcbo. Then swa to a hot tub. That part is fine. What I’m unsure about is the reg I can say that the cables are not ok in the bottom of the main switch. The other dB is only about a ft...
  4. B

    Rating of CU main switch

    Hi all, I noticed on my consumer unit that the main switch is rated for 100Amps, however the total load of all the MCBs is over 150Amps! I appreciate that diversity COULD (?) be applied in that not every circuit would be simultaneously running at full capacity, but is the installation...
  5. T

    Selecting a 3 or 4 pole main switch

    Evening all Pricing up a consumer unit change in a large industrial unit When it comes to selecting a 3Pole main switch for a 24 way distribution board, are there any factors that will change the decision between a 125A 3pole or 4pole main switch?
  6. S


    Installed a new radial circuit in a garage from an existing CHINT garage unit. All functioning well (tests fine) until after the RCD test. Then everything, lights etc stops working. On investigation, while I've got 244V at the incoming side of the main switch I'm getting a reading of...
  7. T

    Correct Lock Off Device for 4 Pole Main Switch

    Hi all & thanks in advance for any feedback. Could anyone tell me the correct Lock off device used to safely isolate a 4 pole main switch? I'm not 100% sure if the isolation device with the prongs is the correct device to be used or if another lock off device is necessary. Pics attached...
  8. Andy C

    Domestic TT earth, Dual RCD or RCBO and Main Switch

    I have a replacement consumer unit coming upon which is currently off a TT system with a nice low reading on the earth. There is no chance of the DNO converting to TNCS. No SPD or AFDD as per client. I intend fitting a new Dual RCD consumer unit. I have researched this site and there was talk...
  9. B

    200A or 250A main switch

    This switch, 250A or 200A? I’m saying 200A but go online and put that XT3N 250 and all it comes up is 250A?
  10. T

    Lock Off Device for Triple Pole Main switch & MCB

    Hi all. I am undertaking an assessment next week called SAFE ISOLATION OF SUPPLIES. It involves isolating and securely locking off a circuit to be worked on. The 4 items to be isolated is THE WHOLE INSTALLATION, A 3 PHASE CIRCUIT, SINGLE PHASE CIRCUIT & LOCAL ISOLATION (which is an isolator...
  11. C

    Electrician 3 phase RCD main switch on Dis board

    Hi guys My friends are selling a house in France and they had an electrical survey which said they need to fit a RCD main switch on the dis board, the supplier has fitted an RCD at the main in coming cables but it’s about 20 yards away from the house and the survey said the dis board must be...
  12. Ian1981

    Mccb used as main switch isolator

    A question regarding the use of a mccb as a 3 phase main isolation switch to a DB. Is it a necessity? Current set up is I have a 3 phase 70mm supply feeding a DB. The origin of this supply is unknown, hence I’m getting northern power out to investigate as the main cut out earthing arrangement...
  13. M

    Using a MCB as a main switch

    My boss has just took over a new site and I went to look the layout. Some boards are damaged some cables need replacing and am sure some other stuff. The site has a old busbar with isolators feed various boards and of her isolators. It also has a board connected directly on to the busbar . The...
  14. B

    Main switch help please

    Hi is this a normal MCCB or MCCB with RCD I’m unsure cause of the earth leakage relay thanks don’t really know the settings on relay I’m apprentice thanks
  15. T

    Anyone know the BS number for Memera 21 board Main Switch

    I've searched the Forum for this, but not getting any hits. Doing an EICR and need the BS number. Any help gratefully received :)
  16. andysparkfree

    100ma 100amp 3phase main switch on TT system and rcd protection on the rest of the circuits question

    Hi all , my question for your brilliant minds is (ill first set the scene) 35mm 4 core swa coming from an external supply, 16mm earth ran out to an earth rod(ze at the distribution board main switch 0.35ohms) now this is quite a large installation with a 3phase distribution board in the...
  17. B

    Calculating main switch size

    My friend, a plumber is at a job with a 63A 3 phase main switch, and the board has a few 20a circuits, a few 10a, and a few 32a. Hes replacing the 20a double pole breaker from the old water heater to a 3 phase 40a breaker, to suit the new heater. What is the formula/calculation to determine the...
  18. Marcus Vaughan

    80amp cut out, 63amp main switch....

    Hi all, I recently carried out an EICR on a two up two down terrace. The cut out out has a sticker on it saying 80 amp. The main switch of the consumer unit is rated at 63 amp. Cleared all the C2 faults but stuck with this. No - I didn't break the seals to check! I did, however, phone the...
  19. P

    New to the forum, 100a main switch problem

    Hi all, Just dropping in first time on this forum, currently in my last year at college studying electrical installation. I have a quick question for anyone who maybe able to help. I have installed a consumer unit today at a new house I have bought, modified the exsisting ring a added 2 new...
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