help with certs for office install needed- supply characteristics

[academy]

Hi all

Hopefully you can help me get my head round which cert is needed and some guidance on completing it. I have 2391 but usually do just domestic. Another spark I know asked me to help install 2 hand dryers (to an office) and issue certs for him as he has no experience of testing.

The client wanted a hand dryer installed to the male and female toilets. We could not get any (ottermill) rcbos to run the circuits from so we used an mcb to supply a two way stand alone rcd unit and then supply each hand dryer from there. I have no problem with testing this part and completing certs, its just how to complete the supply characteristics part. The offices are 4 storey and we had no access to the landords cupboard where the intake would be. The floor we worked on had a tap off box supplying an 80amp merlin gerin single (type u?) phase mcb (no idea of ka as of yet tried google but know joy) with 25mm tails feeding a single phase board (that we ran our stand alone rcd from).
What should I put for type of supply etc?
TN-S? After all there is a seperate earth from the tap off box.

Any help would be great but I have doubts as reading this back I'm not sure how clear I have been

Thanks

 

[academy]

oh no! 33 views and no comments? tumbleweed it is then lol

Someone else must have come across this aswell?

 

[Guest123]

Hi all

Hopefully you can help me get my head round which cert is needed and some guidance on completing it. I have 2391 but usually do just domestic. Another spark I know asked me to help install 2 hand dryers (to an office) and issue certs for him as he has no experience of testing.

The client wanted a hand dryer installed to the male and female toilets. We could not get any (ottermill) rcbos to run the circuits from so we used an mcb to supply a two way stand alone rcd unit and then supply each hand dryer from there. I have no problem with testing this part and completing certs, its just how to complete the supply characteristics part. The offices are 4 storey and we had no access to the landords cupboard where the intake would be. The floor we worked on had a tap off box supplying an 80amp merlin gerin single (type u?) phase mcb (no idea of ka as of yet tried google but know joy) with 25mm tails feeding a single phase board (that we ran our stand alone rcd from).
What should I put for type of supply etc?
You will need to look in the landlords cupboard to find the earthing system for the installation.
TN-S? After all there is a seperate earth from the tap off box.
This wouldn't be the earthing system for the installation though, it's just a sub-main.
Any help would be great but I have doubts as reading this back I'm not sure how clear I have been

Thanks

On a full EIC you need to fill in the supply characteristics as you've stated, this means accessing the main intake to find out what they are, earthing system, fuse type and rating etc.

Obviously then your new DB will be the subject of the circuit details and test result sections together with the details for where it's fed from (existing DB) at the top.

How will you obtain the Ze, by enquiry would be the only way it seems. They could also tell you the earthing system present (if they know themselves).

 

[academy]

Cheers Lenny,

I guess I knew but was hoping to get away with putting down the details of the tap off and sub - board,

Have to go back I guess and try and get someone to unlock the landlords cupboard