earth bonding at outdoor garage

[zombymumf]

I have a TT earthing arrangement at my home. I wish to run a supply to a CU in a garage some 30m from the house CU. Am I right in assuming that I will need to provide another earth rod at the garage to the garage CU? If so, then I am confused about whether to connect the MET in the house to the garage CU through the SWA cable as well?

I will be doing this work and then getting it checked by a Spark afterwards and don't want to appear a fool if I can help it, so any advice would be gratefully received.

 

[wingcoax]

Your sparks will(should) know what to use. After all he will be the one putting his name on the paperwork including the notification to the LABC.

 

[zombymumf]

Your sparks will(should) know what to use. After all he will be the one putting his name on the paperwork including the notification to the LABC.

Hmmm, thanks for that. The point is I want to know the answer before he gets involved. Is there a way of determining this?

 

[bongos]

Ask him/her! That's what you're paying him/her for!

Your spark will be the one signing to say they designed/installed the work so you must make sure that they are happy with the standard/route of the work.

 

[1john]

They need to design it if they are signing it off, you gonna look a bit silly trying to explain to him that 'a couple of fellas off the internet told me to do it'

Get the spark involved from the start and write down anything they tell you to do that you think you may forget so you get it 100% and save yourself some cash incase he/she has to redo any of it because you got it wrong.

 

[chapeau]

Am I right in assuming that I will need to provide another earth rod at the garage to the garage CU?

Yep

If so, then I am confused about whether to connect the MET in the house to the garage CU through the SWA cable as well?

Nope. The house earth should be used to protect the SWA but do not connect the exported house earth to the local earth at at the garage. So connected one end only.

Bonding relates to any other metal bits that might also enter the garage eg a water supply. So if you have these, these need to be connected ("bonded") to the garage earth terminal which is itself connected to the garage earth rod. That is your garage equipotential zone. This should be kept separate from the house equipotential zone.

RCDs should be used to keep things safer.

 

[zombymumf]

Nope. The house earth should be used to protect the SWA but do not connect the exported house earth to the local earth at at the garage. So connected one end only.

Bonding relates to any other metal bits that might also enter the garage eg a water supply. So if you have these, these need to be connected ("bonded") to the garage earth terminal which is itself connected to the garage earth rod. That is your garage equipotential zone. This should be kept separate from the house equipotential zone.

RCDs should be used to keep things safer.

Thanks for the response chapeau. All I wanted from the question I posted was to round off my understanding of what is being done at my home for my own satisfaction and so that I can have an informed discussion with my electrician. I like to 'geddit' and learn stuff. Your response enabled me to do that by confirming my understanding.