Plastic Switchgear Enclosures - Acceptable in barn?

[SparkyChick]

Hi all,

I've tried to find the answer to this question, but I've drawn a blank.

Situation... location is a barn, attached to a domestic property. This will be a sub-board supplied in T+E from the main board in the house.

The question is... is a plastic board acceptable or should it be metal?

My interpretation of the regs is no, plastic is not acceptable because it's attached to the house.

Comments and thoughts?

 

[Ian1981]

Can you install metal containment like galv trunking for the t&e supply?

 

[SparkyChick]

I'm in the process of putting final pricing together for the job and I've been giving it some thought... I'm going to cut a hole in the back of whatever enclosure I use and stick it over the cable entry into the barn... problem solved

 

[westward10]

How are you going to support the swa cables considering the entire area of the barn being an escape route.

 

[SparkyChick]

How are you going to support the swa cables considering the entire area of the barn being an escape route.

I'm planning on clipping the cables to the lights to the roof trusses (metal trusses, using clips designed for the purpose). They are the only cables that will go overhead in open space, the rest will be running along the walls, nothing going over doors. They'll be fixed to the walls with plastic cleats with some glav band on every other one.

 

[SparkyChick]

I wasn’t sure if by ip enclosure you meant plastic.
I should have known better tho

Sorry Ian, didn't really make that part clear originally. My bad

 

[bcm_spark]

Sounds to me like you're sorted

 

[SparkyChick]

sori when I read your first post... "this will be a....." I assumed none of it was in yet

ive used a surface mount meter box before with a metal board inside, took the swa cables through compression glands in the meter box, then armoured glands into the dis board inside it... no creatures getting in there!

That double glanding is what I was planning.

 

[westward10]

As the the board I would definitely choose metal and find a brickie who will knock up a small room to put it in.

 

[Richard Burns]

The main driving force for my question is that metal weatherproof enclosures seem to stop at garage units which only have 3 circuits... this requires more. After that, if you want metal, they become prohibitively expensive... cheaper to whack a non-weatherproof board in a weatherproof box.

According to GN4 the non combustible idiocy is applicable to inside domestic premises and their attached garages/outbuildings and those nearby, therefore I interpret this to mean that with an outbuilding attached or near the house non combustible containment inside the building would be required.

If the largest size consumer unit is 5 module then could you get two consumer units and stack/link them together with non combustible couplers of appropriate size and have a main switch and three circuits in one enclosure and the remaining circuits in the other enclosure whilst maintaining the CCC with link cables ?
It may be a bit of a contrivance but would be more familiar to a domestic user and possibly easier to install.

 

[SparkyChick]

According to GN4 the non combustible idiocy is applicable to inside domestic premises and their attached garages/outbuildings and those nearby, therefore I interpret this to mean that with an outbuilding attached or near the house non combustible containment inside the building would be required.

If the largest size consumer unit is 5 module then could you get two consumer units and stack/link them together with non combustible couplers of appropriate size and have a main switch and three circuits in one enclosure and the remaining circuits in the other enclosure whilst maintaining the CCC with link cables ?
It may be a bit of a contrivance but would be more familiar to a domestic user and possibly easier to install.

I did think about getting two BG garage units as they are 5 modules each. Put the main switch in one and the MCBs in another... unfortunately, but the time you add up the cost of the boards, a main switch and the hardware to join them (and the fact I'm trying to ensure all cables enter through the bottom panel of the CU) and you're costing more than sticking a metal CU inside a meter box.

Plus... as you suggest it's a bit of a contrivance and for me I think it would just look like a bodge job.

I'm pretty happy with the metal CU inside a standard surface mounted meter box. It's not a massive saving, but it cuts some of at least.

Thanks for the discussion guys, much appreciated

 

[Phil Thompson]

According to GN4 the non combustible idiocy is applicable to inside domestic premises and their attached garages/outbuildings and those nearby, therefore I interpret this to mean that with an outbuilding attached or near the house non combustible containment inside the building would be required.

If the largest size consumer unit is 5 module then could you get two consumer units and stack/link them together with non combustible couplers of appropriate size and have a main switch and three circuits in one enclosure and the remaining circuits in the other enclosure whilst maintaining the CCC with link cables ?
It may be a bit of a contrivance but would be more familiar to a domestic user and possibly easier to install.

2x BG shower boards are £80-90, you’ll have a spare BG RCD and 2 spare 50A MCB, they may switch for 8xMCB with ratings of your choosing.
Depends on wholesaler.

 

[The Ghost]

Why put it outside, just a thought you could install it in the house and take supply to outside.

 

[elsparko]

id go for metal for added protection against farmers and their equipment squashing all my nice install.