Newly Floored Attic, What to do with Cables?

Stravos Murphy

We are poking the bear now.

I see many standing gensets.

aido79

Sir Liamalot wrote: »

I see many standing gensets.

But you can agree they are supplies and not phases?

To answer your other question..floor mounted conduit is ok but not the easiest way to do it. It would be much easier to rethink your flooring and will be a better job in the end.

A phase is subjective to a supply?

kramer1

Floor trunking

air

While SL explained it poorly at first, he clearly has 3 phases, just not a normal synchronised 3 phase supply.
If he only ever runs single phase loads from it - as would be common in many buildings with 3 phase incomers, then there isn't going to be any major differences in the wiring.

The bigger issue is that when feeding normal AC distribution kit with an inverter, the inverter is unlikely to be able to supply the fault current necessary to trip overcurrent devices within the specified time period.

air

If you count batteries as supplies (which I do) then I have 6

12VDC Battery: 1.5kWh
48VDC Battery: 12.5kWh
2.5kVA Inverter 48VDC -> 230VAC
6kVA Inverter 48VDC -> 230VAC
600W Grid Tie Inverter 45VDC > 125VDC -> 230VAC
National Grid: 63A @ 240V

if I need more I have 2.75kWh @ 12VDC in my camper I can take another 600W mollified square waiver phase from on a fly lead.

They run isolated (except for grid tie) and simultaneously.
Theoretically I can sync the inverters as one 9.1kVA inverter with about 23.5kVA surge but that would be cruel to such a small battery.

air wrote: »

The bigger issue is that when feeding normal AC distribution kit with an inverter, the inverter is unlikely to be able to supply the fault current necessary to trip overcurrent devices within the specified time period.

Would be an issue if you fed an inverter to a mains distribution board, not so much when you feed mains to an inverter distribution board.

Thanks for the advice Aido.
I'm building a trench but my cheapo router expired after a hot supper.

2011

Sir Liamalot wrote: »

Also I want to put a socket up there from an existing socket circuit. Do I have to use NYMJ or is flex suitable?

3 x 2.5 mm flex or NYMJ would be suitable.

Not at all and all the cables are in fine fettle.

What is the issue with them? I would carry out an insulation resistance test on these cables at a minimum. Even if they are ELV they may be a fire hazard (depending on what is wrong with them of course).

Would something like that comply with regs. or is there any?
All I've been able to find on the issue that cables must be secured.

Strictly speaking cabling in the attic should be run around the edges. To comply with regulations proper mechanical protection should be provided to all acting that is at risk to getting a knock or squashed. I think that an attic that is used for storage presents a risk to cabling. What is shown in the above photo could provide the necessary protection, but I think it is not a great solution as it could crush cabling, could result in tight bending radius of some cables, would be impractical, would need to be bonded, is not designed for this application and would be a bit of a gunter.

Sometimes I find better circuit layouts than what is installed as standard and I implement them if improvements in automation, efficiency or power source are more suitable.

This sounds like an evolving hobby. All the more reason not to go with your restrictive suggestion.

I have 3 phases in my house, one from the grid two homebrew off batteries, a 12VDC workshop radial and a 48VDC house supply. Mostly they're a work in progress.

So now I would be thinking about voltage segregation i.e. ELV cabling not sharing the same containment as LV cabling. This would align with best practice.

aido79 wrote: »

You probably would have been better off putting more time into planning the flooring so that if you really wanted access to the cables all you would have to do is lift a narrow strip of wood covering the cable.

This would not comply with the regulations. There is a risk of a cable being driven through the cabling at a later date. Cabling without mechanical protection should not be close to the surface of wooden flooring.

My solution: Use large plastic trunking such as 2 x 4" Marshall Tufflex.
Advantages:
- Easy access to all cabling making it possible to add / remove cabling
- Cheap
- No bonding / earthing required
- Robust, you could even walk on it.
- Multi compartment is possible
- Simple to install without disconnecting anything.
- Possible to mount sockets on it.
- Conduit can be connected to it.

Keep it simple!