Discuss power to garage in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

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jeffy

hey, if i was to put power into a garage would the feed in the consumer unit have to be an rcbo and then the main incomer in the garage be rcd protected as well or do you only need an rcd at the garage end? the c/u in the house is old and only has rewireable fuses, if it needed to supply the garage through an rcbo im assuming a new board would have to be installed?
thanks for your help.
 
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K

Knobhead

More information needed. First off a you a DIY’r. The cables used will have a big impact on any further replies.
 

Richard Burns

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The requirement for RCD protection of cables is dependent on the type of cable and the installation method. See 522.6 in the BGB.
 
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1

1shortcircuit

More information needed. First off a you a DIY’r. The cables used will have a big impact on any further replies.
Previous posts provide information that would confirm the OP is not a DIY'er:thumbsup
 
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1

1shortcircuit

hey, if i was to put power into a garage would the feed in the consumer unit have to be an rcbo and then the main incomer in the garage be rcd protected as well or do you only need an rcd at the garage end? the c/u in the house is old and only has rewireable fuses, if it needed to supply the garage through an rcbo im assuming a new board would have to be installed?
thanks for your help.

If you were to use SWA cable from a spare way in the Consumer Unit you would not need an RCD until you get to the garage.

How much power is required in the garage? If it's just a socket and light then use an RCBO in a separate enclosure next to the original Consumer Unit.

If the Garage is going to be more of a Workshop then supply via SWA and fit a RCD protected garage consumer unit.

Please posts as much information (demand, route, distance etc) as possible to help with suggestions as to how you can achieve your requirements:thumbsup
 
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J

jeffy

hey, it will be wired in swa and the distance is about 5metres to the garage. The required power will be for a couple of lights and two socket outlets which will not have much demand on them. is it correct if i install an earth stake in garage an rcd feeding garage in house will not b needed?
basically i wanna know which one of the following (if any) ways is correct
1) spare way c/u in house, 20a normal breaker feeding garage, 2.5mm swa to garage to mini c/u with rcd main incomer, 6a and 16a normal breakers for garage
2)spare way c/u in house,old so into new mini c/u with 20a rcbo feeding garage, 2.5mm swa to garage to mini c/u with rcd main incomer, 6a and 16a normal breakers for garage.
hope that makes sense and thanks for your help
Jeff
 

Richard Burns

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Number 1 assuming an insulated CU at the garage and that you have taken all other installation criteria into account should be OK, though there is limited discrimination between house and garage.
(Number 2 would have 2 RCDs in series so the one at the garage would be redundant and should be replaced with a MS)
 
OP
1

1shortcircuit

hey, it will be wired in swa and the distance is about 5metres to the garage. The required power will be for a couple of lights and two socket outlets which will not have much demand on them. is it correct if i install an earth stake in garage an rcd feeding garage in house will not b needed?
basically i wanna know which one of the following (if any) ways is correct
1) spare way c/u in house, 20a normal breaker feeding garage, 2.5mm swa to garage to mini c/u with rcd main incomer, 6a and 16a normal breakers for garage
2)spare way c/u in house,old so into new mini c/u with 20a rcbo feeding garage, 2.5mm swa to garage to mini c/u with rcd main incomer, 6a and 16a normal breakers for garage.
hope that makes sense and thanks for your help
Jeff
What earthing system does the installation use?

I personally would SWA from house and because the cable is mechanically protected there is no need to RCD this length. Just be sure that the MCB rating is equal to or less than the ccc of the SWA being used. Once in the garage I would use an IP rated garage unit with RCD protection. One 16A mcb for sockets and one 6A for lights.
 
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G

Guest123

What earthing system does the installation use?

I personally would SWA from house and because the cable is mechanically protected there is no need to RCD this length.
There is if the answer to your first question is 'TT'.;)
 
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J

jeffy

ok so no need for rcd in house if i use swa to feed garage. thanks.
one other thing, if i just used an rcbo from house to feed garage and just had that one circuit whats the rules on distance etc?
thanks again
p.s someone told me this and im sure its not right!!
 
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J

Jonny66

You are kidding?
that's easy, just use the special rule of thumb from the "Rules of Distance Act 1987" whereby the distance of an unknown cable run can be quantified by using a tape measure and the simple equation U=x/7+9>(weA* tabix -2) and extrapolate how many electrons are present in the known universe, then divide by the cable length.
 

mayfair

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This rule does not apply to speaker cable !
You are kidding?
that's easy, just use the special rule of thumb from the "Rules of Distance Act 1987" whereby the distance of an unknown cable run can be quantified by using a tape measure and the simple equation U=x/7+9>(weA* tabix -2) and extrapolate how many electrons are present in the known universe, then divide by the cable length.
 

Spoon

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You are kidding?
that's easy, just use the special rule of thumb from the "Rules of Distance Act 1987" whereby the distance of an unknown cable run can be quantified by using a tape measure and the simple equation U=x/7+9>(weA* tabix -2) and extrapolate how many electrons are present in the known universe, then divide by the cable length.
42.....
 
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J

Jonny66

Just a thought, I think the "Rules of Distance Act" have just been abolished this morning due to a recent episode of Eastenders, where it was proved that the dark and arcane art of cable calculations were more accurate.
 
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