help me wire this please

[shocksl]

Hey guys


As some of you know I study at York College. I am working on an assignment exam, Which I need some help with.

Fixed appliances:

• 12k W electric cooker with induction hub (no socket)
• 300W extractor over cooker
• 7 KW electrical central heating and hot water boiler.

Building construction :

• Outer walls - brick with wood cladding, insulated cavity
• Inner walls : plasterboard dot and dabbed onto lightweight blockwork
• Floors: laminate flooring on 50mm concrete seed.
• Ceiling lasterboarded through with acess hatch into fully accessible loft void above. Ceiling 2.3m above finished floor level.
• Loft insulation : this 250mm thick and cables are to be clipped to joist or lay on plasterboard.

Electric supply

• 230v , TNCS, with ZE and PFC at 0.3 ohms and 0.77ka
• Amb temp 25 degrees

This is for a 2 bedroom bunglow and I need to wire it.





I have decided the accessories will include the below and with FSU for boiler, and cooker:


2 bedrooms –ill put 1 x light in each room. And 3 x double sockets each room

1 onsuite room – so 1x light – no sockets

Small hallway – 1 xlight and 1 double socket and 1 smoke alarm

Bathroom has sections so 2x lights. 0 sockets

Utlity room – 1 x light plus 2 x double sockets

Kitchen 1 xlight. Plus about 7 xdouble sockets and 2 x single sockets.

Large diner and lounge room integrated.. so therefore 2 x lights plus 5 x double sockets



If you think I should add more please let me know.



What will be the best way to wire this ? since theres concrete under laminated flooring, . I am thinking of taking the cables from the consumer unit and take the wire up to the loft clip to joists and drop to the nearest socket for the circuit and then back up the wall clip up the joist and come down again into the next socket. And repeat until the sockets are complete. For the ring curcuits. Take the wire back again same way


In terms of lights can I just lay them over the plastboard? And it doesn’t matter how they go as theres no safe zone etc. is this correct? So in affect I can just go up the consumer unit abover th plasterboard just go in diagnels if I have to get the light and switches?

once Ive done this I will do all the calcs required.



Any advice would be greatly applreciated. I am more than happy to discuss further,.



thanks

 

[mainline]

Thank you would that come off the light circuit ?

yes

Also can you tell me how would it benefit having more radials than rings please ?

Selectivity.

 

[plugsandsparks]

So would you say drop down from loft to a room go horizontal for all the sockets ie 2 double sockets in bedroom. Then go back up to the loft and drop down into the next room ?

If the layout suits, (i have not looked at the schematic) its possible to drop down once, pick up all the sockets you can horizontally only going back up for obstacles like doors. Also you may be able to pick up the next room by going through the wall and just keep going only going back up if you need to. If say you are going for radials, which i would do for most of the sockets (kitchen / utility probably not) then if you plan it nicely there is just one drop which will save a huge amount of cable and reduce how many opportunities for someone to hang a picture in the wrong place, lol

 

[westward10]

yes

Selectivity.

It has nothing to do with selectively.

 

[shocksl]

yes

Selectivity.

Thank you

So would it be suffice to have

If the layout suits, (i have not looked at the schematic) its possible to drop down once, pick up all the sockets you can horizontally only going back up for obstacles like doors. Also you may be able to pick up the next room by going through the wall and just keep going only going back up if you need to. If say you are going for radials, which i would do for most of the sockets (kitchen / utility probably not) then if you plan it nicely there is just one drop which will save a huge amount of cable and reduce how many opportunities for someone to hang a picture in the wrong place, lol

Lol this has helped alot !!

So to get an understanding I'll take a radial from the CU. Go up to the loft. I can clip direct on the joists or lay on plaster as it says on the assignment brief. So does it matter how I get the cable when its in the left to the required room. So for example if I take I take it up from CU I get in the loft and I need to get into bedroom 2 .. do I need to go arounf the external walls. Or cut straight through in sort of diagonal. I've never done it life lol

 

[plugsandsparks]

In the loft how you get from the CU to a drop will depend. from CU , chances are that the ceiling / roof joists span across the shortest wall to wall distance, if so you can simply clip to these joists, that will put you above the lounge, from there you can take a route to drop down to the sockets in the far side of the bungalow. There are no right / wrong routes in the loft. Need to be clipped, preferably above the insulation but not mandatory as you can de-rate for that. Have a go on the drawing and post...

 

[shocksl]

In the loft how you get from the CU to a drop will depend. from CU , chances are that the ceiling / roof joists span across the shortest wall to wall distance, if so you can simply clip to these joists, that will put you above the lounge, from there you can take a route to drop down to the sockets in the far side of the bungalow. There are no right / wrong routes in the loft. Need to be clipped, preferably above the insulation but not mandatory as you can de-rate for that. Have a go on the drawing and post...

Thank you so much that has had made alot of sense. I appreciate you giving your time.


I'm going to have a go this afternoon to draw it on.

The only other considerations I really need to make is installation reference method.

I'm not sure whether inside the walls it needs to be enclosed in a conduit or not.

In the loft as there is 250mm insulation. I will be clipping sides of the joists. Given that a standard joists is under 230mm . It will be affected so I cable calcs I'll include that factor. However i don't think it needs any conduit or trunking at this stage in the lift.

Below is a reminder of the building structure.



Building construction :

Outer walls - brick with wood cladding, insulated cavity
Inner walls : plasterboard dot and dabbed onto lightweight blockwork
Floors: laminate flooring on 50mm concrete seed.
Ceiling lasterboarded through with acess hatch into fully accessible loft void above. Ceiling 2.3m above finished floor level.
Loft insulation : this 250mm thick and cables are to be clipped to joist or lay on plasterboard.

 

[mainline]

Thank you so much that has had made alot of sense. I appreciate you giving your time.


I'm going to have a go this afternoon to draw it on.

The only other considerations I really need to make is installation reference method.

I'm not sure whether inside the walls it needs to be enclosed in a conduit or not.

In the loft as there is 250mm insulation. I will be clipping sides of the joists. Given that a standard joists is under 230mm . It will be affected so I cable calcs I'll include that factor. However i don't think it needs any conduit or trunking at this stage in the lift.

Below is a reminder of the building structure.



Building construction :

Outer walls - brick with wood cladding, insulated cavity
Inner walls : plasterboard dot and dabbed onto lightweight blockwork
Floors: laminate flooring on 50mm concrete seed.
Ceiling lasterboarded through with acess hatch into fully accessible loft void above. Ceiling 2.3m above finished floor level.
Loft insulation : this 250mm thick and cables are to be clipped to joist or lay on plasterboard.

Also, don't forget to take into account reg 521.10.202

 

[mainline]

It has nothing to do with selectively.

Selectivity refers to the ability of a system to isolate a fault to a specific section, minimizing the outage to only that section and not the entire system.


Selectivity Previously known as discrimination, selectivity is the ability of the protective device to operate in preference to another device, which is in a series connection configuration. For correct device coordination, short-circuits, overcurrents and residual currents will need to be considered.

• In a radial circuit, the fault current is limited to the specific circuit where the fault occurs, as there's only one path for the current to flow. This makes it easier to isolate the fault and restore power to other parts of the system without disrupting the entire network.
• Easier Coordination of Protective Devices:
  When designing a radial system, it's easier to coordinate the tripping characteristics of circuit breakers or fuses to ensure selectivity. This means that a fault on a downstream circuit will trip the circuit breaker on that specific circuit, while upstream circuit breakers remain intact.