A3 radial circuit ????

[martinh89]

Im currently training as an electrician through ATL but i have actually been to college and done my level 1 and 2, plus had on site experience to a cirtain degree.

my friend has asked me to put a new circuit from the consumer unit to his loft as he is converting it, he wants 2 socket outlets to supply 4 lights at 600w.
my question is :
what is the best way to go about the installation? ,from what ive learnt and done in the past id use an A3 radial circuit using 2.5mm twin and earth with a 20a mcb

i was wondering have i got it right or far from it ?

thanks

 

[martinh89]

As you quite rightly calculate that 4 x 600w would equate to over 10 amps so putting that on the end of a radial with sockets would NOT be the way to go.

Looks like you need 1 x radial for the sockets and 1 x radial for the lights - both 2.5mm and 16a breakers (or you could go to 20A depening on the cable routing).

And as new circuits its notifiable and does the house have RCD's and bonding in place?

cheers mate , theres no radial circuit for the lights , its just 1 radial circuit for the socket outlests for plug in lights , the cable run is pretty straight forward , straight up from the downstaires C/U to the loft in trunking.

He does have a socket on the staires directly under the loft on a ring main, could i branch off that by any chance without installing a new circuit ?????

 

[Octopus]

cheers mate , theres no radial circuit for the lights , its just 1 radial circuit for the socket outlests for plug in lights , the cable run is pretty straight forward , straight up from the downstaires C/U to the loft in trunking.

He does have a socket on the staires directly under the loft on a ring main, could i branch off that by any chance without installing a new circuit ?????

Hum, maybe, how familiar are you with rings, radials and spurs?

 

[martinh89]

Hum, maybe, how familiar are you with rings, radials and spurs?

in what way do you mean ?

 

[i=p/u]

He mean do the sums and protect the cable/circuit in question and dont compromise the existing circuit

 

[Octopus]

in what way do you mean ?

If you want to plug in 4 lights, which method of socket circuit design would be compliant with the regs?

Hint - BGB p 425/426

 

[martinh89]

If you want to plug in 4 lights, which method of socket circuit design would be compliant with the regs?

Hint - BGB p 425/426

regarding the radial circuit im pretty clued up with the regs and using 2.5mm cable and a 16mcb,its compliant, as for the ring main and branching off of it not so much

 

[HandySparks]

He does have a socket on the staires directly under the loft on a ring main, could i branch off that by any chance without installing a new circuit ?????

If the existing socket is on the ring, you could spur off via a 13A fused connection unit, but with the loading of the lights, you wouldn't have much spare capacity for any other loads.

 

[Knobhead]

What calculations have you done? I would guess non, you just thought the people here would do the work for you.

 

[i=p/u]

lol and too supposrt some drug pushing c .................. but as poster says it cash in his hand...

 

[martinh89]

Like i said at the begining of this thread iam training to become an electrician so i came on here for as much help and advise i could get, the calculation ive done so far is for the fuse rateing . 4x600w=2,400w ÷230v =10.3473....amps.
Ive checked the regulations and the cable size and fuse size i plan on using comply with regulations, if ive missed anything please fill me in i acyually would be greatful .....<- not sarcasm

 

[morph]

2.5mm straight out from the main fuse to keep the lecy bills down

 

[Brightspark2]

i have no idea, ask no questions hear no lies, to be honest im just greatful for the work

ha ha 100% growing then...


You want the sockets to plug the lights into right?, well run the 2.5mm radial up to the loft and put the 2 socket outlets in on a 16A or 20A what ever you see right.

The socket under the stairs may be part of the ring final circuit in the house of which you could only take 1 unfused spur from so adding the new sockets onto that existing socket is a no.

You calculations of the current does it take into account the power factor?...

Now thats sorted what are you going to do about the big red thermal image that will appear on the cameras when the police helicoptor flies over ha

 

[Octopus]

Like i said at the begining of this thread iam training to become an electrician so i came on here for as much help and advise i could get, the calculation ive done so far is for the fuse rateing . 4x600w=2,400w ÷230v =10.3473....amps.
Ive checked the regulations and the cable size and fuse size i plan on using comply with regulations, if ive missed anything please fill me in i acyually would be greatful .....<- not sarcasm

You could use the "thanks" button on the thread replies.

IF you install a new RADIAL you will be OK, but then you'll have to deal with Part P, RCD's and bonding

IF you install a spur for 2 sockets off an existing ring you won't have to deal with part P but you will need to deal with RCD,s bonding and your modification won't comply with the regs.

 

[Knobhead]

Does commercial horticulture come under the realm of part P?

 

[morph]

Does commercial horticulture come under the realm of part P?

it does if the supply is from a common metered supply, hence my suggestion to bypass the meter ;-)