NAPIT Certification Scheme Is my work going to be appropriate for Napit first assessment?

[King84]

Hi everyone
My Napit assessment is approaching and it would be nice to get some feedback for my planned work on my of my friends workshop.

There is already a consumer unit but its without RCD protection and thats on the shop floor.
My plan is to make two circuits one lighting 6A and one Ring final circuit 32A in the workshop . I would hopefully install 3 spotlights and for ring final circuit 4/5 sockets .
But instead of connecting both circuits to main consumer unit I am planning to install Sub DB in the workshop which is Axiom Metal 17th Edition Garage/Workshop Consumer Unit 3 Way - https://www.toolstation.com/axiom-metal-17th-edition-garageworkshop-consumer-unit/p36399.

As I will only be using 6A and 32 and leave the 16 as spare so shall I just use 6mm cable to connect SubDB with main DB as it has Iz of 47A and my potential current usage would be 38. Furthermore as the main DB does not have RCD protection so I decide to install subdb for workshop which would have RCD protection for my circuit but I would only be showing the I have installed two circuits and leave the subDB out for any hassle.
Any suggestions and positive feedback is appreciate. Thanks in advance guys

 

[SparkyChick]

What cable are you planning on running the sub-main in? What route will it be taking?

Why the Axiom? If you've not seen them, BG do a nice IP rated garage board for about the same price.

As for the ratings... how are you planning on protecting the submain in terms of OCPD?

Have you considered equipotential bonding in the garage? Is there any requirement for it? What earthing system do you have?

Overall, it should be acceptable for an assessment. But you need to be sure it's compliant and well designed.

 

[JBW175]

What cable you running the circuits in? Is there any need for containment to protect it? As it’s in a workshop environment.

What’s the rest of the installation like? Is there a chance he’s going see any non compliance’s on there and ask why you’ve not sorted them out?

 

[King84]

What cable are you planning on running the sub-main in? What route will it be taking?

Why the Axiom? If you've not seen them, BG do a nice IP rated garage board for about the same price.

As for the ratings... how are you planning on protecting the submain in terms of OCPD?

Have you considered equipotential bonding in the garage? Is there any requirement for it? What earthing system do you have?

Overall, it should be acceptable for an assessment. But you need to be sure it's compliant and well designed.

Thanks for your reply. The mainboard is under the stairs and workshop is about 2 meters away next room so I am planning to use trunking to run the main cable to connect the main DB with sub DB and planning on using 6mm cable
In terms of OCPD, I am thinking of using a 40A circuit breaker. If I have additional protection RCD do I still have to think about equipotential bonding as main protective bonding is done and I don't think there is any extraneous conductive part but I will still check with Mft if there is any metal that needs equipotential bonding and the earthing system is TNS.

 

[King84]

What cable you running the circuits in? Is there any need for containment to protect it? As it’s in a workshop environment.

What’s the rest of the installation like? Is there a chance he’s going see any non compliance’s on there and ask why you’ve not sorted them out?

Hi JBW thanks for reply.

I spoke to Napit and all they said ask your friends or family if they allow you to install two new circuits so I am assuming I am not responsible for non-complients for the rest of installation but only for two circuits that I will be installing and of course I will be making sure that readings are all appropriate or do I have to consider other installation aswell?
In terms of main cable 6mm SWA 3 core thats what I am planning to think or do you think as its just in the next room so there is another option

 

[JBW175]

Hi JBW thanks for reply.

I spoke to Napit and all they said ask your friends or family if they allow you to install two new circuits so I am assuming I am not responsible for non-complients for the rest of installation but only for two circuits that I will be installing and of course I will be making sure that readings are all appropriate or do I have to consider other installation aswell?
In terms of main cable 6mm SWA 3 core thats what I am planning to think or do you think as its just in the next room so there is another option

I’d probably be inclined to split tails at the origin using Henley blocks to a switched fuse, then 6mm SWA to the Workshop CU with a 30ma RCD main switch. Then run out a lighting circuit and an RFC for the sockets.

 

[King84]

I’d probably be inclined to split tails at the origin using Henley blocks to a switched fuse, then 6mm SWA to the Workshop CU with a 30ma RCD main switch. Then run out a lighting circuit and an RFC for the sockets.

Hi JBW this sound very interesting. Could you explain abit more about how you mentioned connecting tails to switched fuse as I am abit lost sorry as this does sounds like a perfect setup but I am not very experienced as its only been couple of years I have been working so never really been through this setup .
if I decide to use 6mm 3 core unarmoured would that still be ok as I know what you are saying is the perfect scenario but if I still go with what I explained do you think that is a poor setup .