rcd on commercial

[Robert Turnbull]

Does a commercial install not need rcd protection if there are no special locations And no sockets for public use
(It's a car showroom)

Cable runs on tray then in stud walls

Cable in stud walls was my concern of doubt for the rcd

 

[bigbaddave]

I don't have my commercial copy of BS7671 but the last time I read it it was identical to the domestic book (Thats a joke) The regs are the regs regardless of what install it is going in.

If your installing one then yes RCD protect it, a cleaner plugging a hoover in or a customer charging their mobile phone is not a skilled person IMO..

Do you have this job to do or is it just a general question ?

 

[telectrix]

if sockets are to be use by skilled or instructed persons, then there is no need for RCD protection. 411.3.3, 522.6.8.

 

[scotsparky]

but cables less than 50mm or that can be used outside equipotential zone do. RCD it no problems and better safe than sorry

 

[telectrix]

right on the 2nd bit, scot. the <50mm rule is detailed in 522.6.8.

 

[Robert Turnbull]

Going to have a reg read I think. The middle of pricing a job,

This is the first decent size commercial install I've had (not installed, had as my own job) so I'm double checking everything. I assumed rcd but wil have a reg read up.

RCBO'S will make a big price jump but if they needed then they needed.

 

[telectrix]

your call as to whether the sockets will be used by skilled persons. if in doubt, go for RCBO or RCD protection. with RCBOs , you're looking at an additional cost of £20 per circiut ( difference in price between MCB and RCBO ).

 

[snowhead]

Cable runs on tray then in stud walls

Cable in stud walls was my concern of doubt for the rcd

Can you guarantee the cable will be always be at a depth greater than 50mm?

For car showrooms, think valeting, inside and out.

 

[telectrix]

any sockets for outside use, agreed, but the <50mm reg. is also dependent on the skilled persons clause. as i said. 522.6.8.

 

[Robert Turnbull]

Can't guarantee 50 mm as they prob 2 x 4 studs Walls.

I might just put one ring on rcd where the cars are and maybe put a external socket on it to.

Thanks guys.

 

[electric will]

Can't guarantee 50 mm as they prob 2 x 4 studs Walls.

I might just put one ring on rcd where the cars are and maybe put a external socket on it to.

Thanks guys.

Are the cables to the light switches buried less than 50mm? Won't the lighting circuits need rcd'ing too?

 

[Robert Turnbull]

Can't guarantee 50 mm as they prob 2 x 4 studs Walls.

I might just put one ring on rcd where the cars are and maybe put a external socket on it to.

Thanks guys.

Are the cables to the light switches buried less than 50mm? Won't the lighting circuits need rcd'ing too?

any sockets for outside use, agreed, but the <50mm reg. is also dependent on the skilled persons clause. as i said. 522.6.8.

What telectrix said

 

[Engineer54]

I don't have my commercial copy of BS7671 but the last time I read it it was identical to the domestic book (Thats a joke) The regs are the regs regardless of what install it is going in.

If your installing one then yes RCD protect it, a cleaner plugging a hoover in or a customer charging their mobile phone is not a skilled person IMO..

Do you have this job to do or is it just a general question ?

Never heard of a commercial BS7671!! So what's the difference?? As far as i've always been concerned, BS7671 has always covered basic requirements of all sectors, Domestic, Commercial and even Industrial!! Different 17th exams as well?? lol!!!

 

[Deleted member 26818]

Does a commercial install not need rcd protection if there are no special locations And no sockets for public use
(It's a car showroom)

Cable runs on tray then in stud walls

Cable in stud walls was my concern of doubt for the rcd

No, BS7671 does not require RCD protection in the circumstances you describe.
A cleaner plugging in a hoover, must by law meet the definition in BS7671 to be considered as skilled or instructed.
A customer plugging in a mobile phone charger is another matter.
However if the customer is to be supervised whilst plugging in the charger, by a skilled or instructed person, then RCD protection is not required.

 

[Darkwood]

My veiws on this are the regs clearly state rcd protection required for sockets for general use and by ordinary persons.... the exception of under the supervision of skilled or instructed persons is exampled in some commercial and industrial locations, i would interpret this as locations where equipment etc been used or normal use of the sockets could lead to nuisance tripping of an rcd and instructing the client or other skilled persons allows for ommitance ...

A cleaner popping in before and after the showroom is open will not be under the supervision of a skilled and instructed person as they may not be there, she is using the sockets for general use too ... i often see people trying to use this clause to save a penny or two on costs but i would always cover socket circuits with rcd protection regardless unless the set-up was such that this would create more issues than it solves and that is when and only when i would omit the rcd by going down the intructed persons route.