replaceing consumer unit in shed (with no earth)

[Avidude]

hi i am looking to take my napit exam.
i want to replace a garage consumer unit,
i have looked and found that it is using the swa as the earth (2 core swa)
what can i do?
can i use the swa as the earth for the new consumer unit?
i don't want to have to use a TT system.
thanks for any input
avidude

 

[Amp David]

No cos its protected by the wire armour.

 

[Avidude]

thank you for all your help.

 

[Avidude]

i thought that you all might be interested that the swa was fed by 30amp fuse
the swa was only 2.5mm and outside there was a consumer unit with 30amp and 5amp fuses.
is this the level of workmanship about 20 years ago?

 

[Avidude]

one more thing,, the swa is part runing along the fence not under ground.. there is no poblem with this right?
thanks

 

[telectrix]

no prob. along fence as long as it is adequately secured .

 

[Deleted member 9648]

as both previous posts. earth rod,(missing drains etc) drill concrete floor, whack it in, no aggro with exsported earth, connection in proper box and flagged with safety earth blah, blah tag., 10mm G/Y in pvc tube to CU. nice job.

Aggro with an exported TNS earth.....????........
Regardless of whether you TT or take the sensible option of 'exporting that nasty old earth' you will have to ensure the armour of the SWA is effectively earthed,that will mean earthing it from the supply end,if you are having to do that anyway what is the point of separating it at the garage and rodding?

 

[Des 56]

i thought that you all might be interested that the swa was fed by 30amp fuse
the swa was only 2.5mm and outside there was a consumer unit with 30amp and 5amp fuses.
is this the level of workmanship about 20 years ago?

There were good bad and ugly standards 20 years ago as there are nowadays

Electricians in the past were generally trained through apprentiships in a much broader field than training for being a domestic installer, which seems to the way of the present

As in all walks of life there will be all sorts to make up an industry
Critisism of standards is a thorny issue to take on board

How do you measure a satisfactory standard,some older more experienced sparks on this forum would not take kindly to a sweeping statement of those standards of 20 years ago