how to connect the following?

[sparkymarky123]

i take it the c type mcb would allow for better start up current draw?

 

[sparkymarky123]

I reckon the 13A supply from the FCU will be fine, not the best practice. Far better to run a 6mm T&E from the CU to connect to the 6mm SWA on a 25A/32A MCB then onto a 3 way garage CU. A bit more cash to dish out, but better all round...

i will look into this tomorrow in a bit more depth i think. my c.u is just inside the front door on the same wall as the front door at chest height and fully visible. will have to be careful with the plasterboard etc but will have a look tomorrow i think

 

[Engineer54]

i take it the c type mcb would allow for better start up current draw?

A C type MCB will allow for a higher ''inrush current'' than a B type without tripping.

 

[sparkymarky123]

ahhh yea thats what i thought, thankyou @)


just looking at the c.u. it is mounted in the hall at the very front of the house on full view to the right of the front door. it needs to get to the rear of the house. Thus it seems ( and i know you guys cant see my house! it's either a long ceiling run or underfloor run from the front of the house to the rear. not really wanting to have to pull up 1st floor or ground floor boards though.

Wish i could do it that way but just seems too much to do (especially with the nice oak flooring i have in the hall haha)

 

[sparkymarky123]

if, after a further invest tomorrow i cant run a new circuit from a spare way, and stick with the fused spur, do you think i should stick with the 13a spur or get a 20a one as i originally planned for, as obviously the 6mm swa cable can carry such a load out to the garage

 

[Engineer54]

if, after a further invest tomorrow i cant run a new circuit from a spare way, and stick with the fused spur, do you think i should stick with the 13a spur or get a 20a one as i originally planned for, as obviously the 6mm swa cable can carry such a load out to the garage

Personally i'd first try it with the 13A supply as it's already in and see how it goes. If you have problems then start thinking about alternative arrangements. I think you'll find though, that diversity of connected loads is underestimated, an you'll probably be OK. Get yourself an amp clamp if you haven't got one, and check for yourself what sort of current your drawing in given situations. As i said though, you may need to change the MBC to a C type to take care of higher inrush currents from the compressor starts....

 

[Richard Burns]

Can't really fault the practical advice above, just make sure you have some 13A fuses available! But really you should find you are OK.
On the wiring arrangement you could replace the garage socket with a small CU and have the SWA only fused by the ring OPD, but as stated above may have overload on the ring problems.
Done a quick possibility diagram of wiring for you.



If your PIR does not have the fourth contact (L', or the like, usually for connecting another light) then you will not be able to switch it on permenantly
I would tend to put an isolator switch in for the PIR so you can switch it off easily for maintenance, but this is the basics.
You could change the R7 lamp in the PIR for a low energy one at about 24W to save power.
You may also find that the terminals of the lights are a bit tight for 2.5mm but so long as you do not need to double up you should be OK, you may need to change the terminal block in the flourescent for a 30A one to get the size.
Again if you can get any one in to do this would be a good idea.

 

[JamesBrownLive]

Is the existing ring that you are using protected by an RCD?

 

[sparkymarky123]

Can't really fault the practical advice above, just make sure you have some 13A fuses available! But really you should find you are OK.
On the wiring arrangement you could replace the garage socket with a small CU and have the SWA only fused by the ring OPD, but as stated above may have overload on the ring problems.
Done a quick possibility diagram of wiring for you.

wow , thankyou for taking the time to draw a circuit. should help no end . As you suspected, from memory when i wired the PIR the other day, it had four terminals but the fourth terminal had a black cable in it at both sides already. I dont know if it had L' on it though, i will check. But i got the 2.5mm in it without much hassle.

 

[sparkymarky123]

slight update, had a friend round today who's a domestic electrical engineer. He recommended similar as said on here; i.e taking the floor up upstairs, running 6mm t&E (down the wall into the 1 spare left in the c.u and along the upstairs underfloor to the rear of the house, eventually dropping down next to the socket i was planning on spurring off and out through the rear wall as i was going to straight into the 6mm swa.

Like you guys said, he thinks I may well get trips otherwise. One annoying thing upstairs is its wayrock floor so annoyingly have to cut holes in it

 

[sparkymarky123]

Is the existing ring that you are using protected by an RCD?

Yep it is

 

[AlanWirral]

As said what's been done isn't 'Wrong' as such but when maximum current is drawn it could trip and basically annoy you. Had a mate who did something very similar actually.

More annoying I advised him what to buy and I offered to get it all trade price, like 54 said...new circuit from from the CU to a 3 way board in garage. Running a compressor/lights inc flood/sockets. Turns out he spured off the house ring which at Xmas last year was already getting battered by his kids. He was in the garge with his heater/lights on and as soon as the compressor started it tripped the ring. He's been asking me to 'Sort' it ever since