Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 9 replies
  • Subscribers 32 subscribers
  • Views 705 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Multi-way domestic switch fuse: does anybody make one?

Chris Pearson
Scenario is intake in a store room: the other part of the building, which forms the front boundary of the plot, is the garage.


25 mm2 SWA supplies the house, which is at the back of the plot, and the intention is to protect it with an 80 A switch fuse in the hope that it will provide a measure of discrimination should a fault occur in the house (max 32 A MCB). Clearly there is plenty of choice here.


One option for supplying the garage is to put its CU adjacent to the intake and connect the tails to it (via Henley blocks) but Sir would prefer to have it in the garage itself. The distance back to the intake is unlikely to be less than 3 m, which rules out the possibility of putting the tails through the internal wall.


So if the CU is to be in a separate room, it seems that a second switch fuse is required. It would be so much neater if there could be one device with one switch and two (or more) fuses. I cannot find one, but does such a beast exist please?
Parents
  • 0

    mapj1:






    Cos

    (1) that would require a JB downstream of the fuse, which wouldn't be easy to fit, so may as well have two switch fuses; and

    (2) the branch line would have to be 16 mm2 which would be overkill.


    1) So you cannot fit two cables to one switch fuse ? Or an   adaptable box  and some line taps?

    2) is the max demand in the garage so high you'd need the full fat cable size - if only 32A breaker and 6A lights, then some 6mm would do  so long  as S/c protection is OK.




    I fear that I must defer to Mike's wisdom. I had forgotten that the sum of the final circuits means that there would be no overload of a smaller cable to the garage.


    The length of the cable is so short that a s/c at the downstream end would still allow ADS to function.


    All that said, if it were my house, I would make provision for 32 A worth of EVCP.

Reply
  • 0

    mapj1:






    Cos

    (1) that would require a JB downstream of the fuse, which wouldn't be easy to fit, so may as well have two switch fuses; and

    (2) the branch line would have to be 16 mm2 which would be overkill.


    1) So you cannot fit two cables to one switch fuse ? Or an   adaptable box  and some line taps?

    2) is the max demand in the garage so high you'd need the full fat cable size - if only 32A breaker and 6A lights, then some 6mm would do  so long  as S/c protection is OK.




    I fear that I must defer to Mike's wisdom. I had forgotten that the sum of the final circuits means that there would be no overload of a smaller cable to the garage.


    The length of the cable is so short that a s/c at the downstream end would still allow ADS to function.


    All that said, if it were my house, I would make provision for 32 A worth of EVCP.

Children
No Data

Community Rules & Guidelines