Little confused at the moment about garage installation

[sim2kuk2009]

Hi all,

im going to be installing a consumer unit into my brothers garage coming from his consumer unit in is home im just wondering now weather or not ill have to test the whole consumer unit in his home or just the circuit ive installed. i know i need to test all circuits in the garage. Im thinking ill have to test the whole board but im hoping i wont.

thank yo all.

 

[EddieB]

You only have to test the new works, as it is aa additional Cu you'll do all the tests that will show if there is a problem with the origin of the install, Ze, Pfc etc if you have a problem with it at the new unit you'll have to work it back to the original Cu and take it from there.

 

[Scott F]

I was under the impression that if you ADD a new circuit to an Existing board

you had to test the whole board to ensure that the extra load its taking is sufficient and Safe to do so

Thats why there is a tendency to split the tails into Henley's then just run any new circuits from new 1/2way

board you have installed . = less testing

 

[sim2kuk2009]

that makes sence but also by slpit the tails it allows me to not test both boards excellent thanks for the reply.

 

[Scott F]

You might want to click on the Thanks logo its the one to the right with the thumbs up

you may even want to click on it a few times

 

[U Jay]

I was wondering about this also. If you use Henleys and split to a second unit, would you RCD protect the supply to the garage and then include another RCD in the garage CU?

 

[saveloy]

I was wondering about this also. If you use Henleys and split to a second unit, would you RCD protect the supply to the garage and then include another RCD in the garage CU?

No. You only use one RCD either at the supply end or in the garage CU. You cannot have 2 RCDs of the same rating on the same circuit as there would be no discrimination between the 2.

Also you do not have to test any other circuits apart from the ones that you yourself have worked on. Electricians use henly blocks for a variety of reasons. But the reason given " to avoid having to test an old board" is not a valid one.

 

[ezzzekiel]

including testing the circuit feeding the new board

 

[saveloy]

including testing the circuit feeding the new board

Yep. Sorry, left that bit out.

 

[U Jay]

Thanks for that, suppose an RCD at the supply end is better as it would protect the SWA feeding the garage unit also?

 

[TPES]

Thanks for that, suppose an RCD at the supply end is better as it would protect the SWA feeding the garage unit also?

You can get away without using an RCD at supply end if your using SWA for the feed to second CU.

 

[Scott F]

Electricians use henly blocks for a variety of reasons. But the reason given " to avoid having to test an old board" is not a valid one.[/QUOTE]

Could you elaborate further please

 

[saveloy]

Electricians use henly blocks for a variety of reasons. But the reason given " to avoid having to test an old board" is not a valid one.

Could you elaborate further please[/quote]

Sure. Whenever new circuits are installed to an existing board there is no requirement to test any other cct on that board, other than the newly installed ccts. Whether or not you have a new stand alone board to cater for the new ccts, or use the old board, the amount of testing required remains the same.

Henly blocks are used to split the supply for different reasons- there may not be enough ways on the old board to accomodate the new ccts. If it's an old 16th edition ccu then to arrange new ccts in such a way to minimise disruption it may be easier just to put in a new 2nd board with RCBOs. The old board may be rewirable fuses, so to avoid having to fit a whole new board for say just 2 new ccts it may well be more cost efficient to split the supply and fit a new stand allone ccu.

Hope this helps.

 

[Scott F]

Could you elaborate further please

Sure. Whenever new circuits are installed to an existing board there is no requirement to test any other cct on that board, other than the newly installed ccts. Whether or not you have a new stand alone board to cater for the new ccts, or use the old board, the amount of testing required remains the same.

Henly blocks are used to split the supply for different reasons- there may not be enough ways on the old board to accomodate the new ccts. If it's an old 16th edition ccu then to arrange new ccts in such a way to minimise disruption it may be easier just to put in a new 2nd board with RCBOs. The old board may be rewirable fuses, so to avoid having to fit a whole new board for say just 2 new ccts it may well be more cost efficient to split the supply and fit a new stand allone ccu.

Hope this helps.[/QUOTE]

Would like to REVISE my reply and apologies for mis -information

If you add a circuit to an existing installation there is NO need to test the whole board. Just the circuit you

are working on. Saveloy thank you for your informative and articulate reply . I go now with my head

hanged in shame . Yes that is me staring forlornly at the river below

 

[ajelec10]

When spliting the tails with 'henly blocks you must also consider installing a mian switch before them to provide a single point of isolation for the installation, other wise you end up with two or more main switchs.
Regards
AJ

 

[leonard290]

that makes sence but also by slpit the tails it allows me to not test both boards excellent thanks for the reply.

dont forget the earth rod