Conduit for shed slab.

[Com_VC]

Getting a slab done at the moment for a 6m x 6m steel shed and thought it would be a good idea to run the conduit in through the slab rather than put it in afterwards.

Just wondering what the best size to run would be. Keep in mind want to run a fair few power points. say 8 double power points, 240volts 10a and some 15a, lighting etc.

Basically just want to make sure the conduit is large enough to accomodate but not too large.

Also what are the regulations regarding depth. By the way the distance isn't that far, there is a shed behind to hook into. about 1.5 metre away

I want to run a new fuse box in the new shed. Generally is there one main feed line that will care of the lights and power points or is there a few?

Any advice would be good.

Thanks

[wozzzzza]

just done similar myself, ive been told by electricial minimum depth 60cm, use 25mm orange conduit.

[nev25]

My advice it to get a sparkie in now.
Pulling cable though conduit thats already in the ground is a Pain in the Ass

[Ivan in Oz]

32mm MINIMUM....that's what I used, so much EASIER

YES!!!!

Pulling can be a Pain.
Get it in before you start,
else get in a draw wire.

When pulling,
Use plenty of Lube, Specially formulated Cable Pulling Commpound,
NOT Detergent or Oil

You can run the Power Point [GPO] cabling within the Framework.

As Nev25 said,

GET A SPARKIE

[Yonnee]

Minimum 600mm below ground.

Minimum 25mm conduit and get the 'large radius' bends, makes it easier to pull the cable through. I pulled a 10mm 2C+E plus a 2.5mm 2C+E and two single cores through a 32mm conduit running 16MTS. Not difficult, just time consuming by yourself.

The thing to be careful of is that if you intend to dig the trench and lay the conduit yourself, don't fill it in till you've spoken to your sparkie, or you know one. Most won't like to sign off on the job if they don't know how deep you've put it. (And they won't take your word for it).

[thatirwinfella]

this was covered barely a fortnight ago, with a member wanting to lay conduit under his driveway. a quick search will find it.

all relevant and legal depths were mentioned, 600mm under concrete is overkill, you can go shallower as is mentioned in the other thread, and as your sparky will tell you.

[Com_VC]

It's not under concrete though. Just dirt. What we have is an existing garage attached with the house (brick) and we are putting a 6x6 colourbond steel shed. They are about 1.5 metres apart from each other.

So I assume 600mm is the go?

I bought some orange conduit from bunning yesterday in 32mm. I didn't get any bends yet as they only had them in white which I would assume wouldn't suit.

Also will it be ok if the conduit sits right at the edge of the slab? Not going to cause the concrete to crack or anything like that?

Just curious, to get around digging 600mm can you place a bit of steel plate over the conduit to protect it or some other suitable material?

Thanks

[Vernonv]

Just curious, to get around digging 600mm can you place a bit of steel plate over the conduit to protect it or some other suitable material?

It can be buried directly under concrete (if I recall correctly), but you'd want to check the specifics with a sparky.

[Ivan in Oz]

I bought some orange conduit from bunning yesterday in 32mm. I didn't get any bends yet as they only had them in white which I would assume wouldn't suit.

Also will it be ok if the conduit sits right at the edge of the slab? Not going to cause the concrete to crack or anything like that?

Just curious, to get around digging 600mm can you place a bit of steel plate over the conduit to protect it or some other suitable material?

Thanks


This is where you Really DO need the Sparkie

Yes, you are Correct
No, but then my Shed used House Type Framing
and
Yes, something better........Completed the Conduit Run

[nev25]

Id like to know where this 600mm comes from
The regs state 500mm if in HD conduit
But most sparkies prefer 600mm just to be sure.

No restriction on size of Conduit

Actually you can used MD conduit if its chased in concrete

There are a few variables depending if its a category A,B or C wiring system.

But a sparkie will be able to tell you.

Yonnee Why did you run so many circuits seems to me to be an expensive way of doing things

[rileyp]

I thought the reg was 300 if in an area that vehicles cant get to.
I haven't done a u/g in 7 years though...
cheers Rileyp

[patty]

Its always been as long as I can remember 600mm and Ive been doin it for a long time now...

Just to follow up on what Nev25 stated about Yonnee

I pulled a 10mm 2C+E plus a 2.5mm 2C+E and two single cores through a 32mm conduit running 16MTS. Not difficult, just time consuming by yourself.

You do understand that installing multiple circuits in one conduit can De-rate the cable/cables obviously pending on the Max demand and if the derating factor was considered in the installation !!

[Spider Webb]

Going by 07 wiring rules what your describing is a Cat A wiring system that needs a minimum 500mm above the top of the conduit with warning marker tape 250mm above that, so depending on the size of conduit you use you go close to 600mm fir the total depth.

300mm if you put min 75mm of concrete above the conduit

Dig the trench for the Electrician and you will save yourself some money.

Stewart

[Com_VC]

another quick question. Can you used the white bends with orange conduit or do they have to be orange?

Thanks

[Vernonv]

The cable must be enclosed in heavy duty conduit. So are the white bends heavy duty? Maybe? Probably?

Personally I would go for orange bends as you can be sure that they are heavy duty.

[Spider Webb]

As long as they are heavy duty.
I'm assuming if you are worried about what bends to use, that you will be getting a electrician to finish it off for you, so why aren't you asking him what to put in. As Yonnee said earlier most won't touch the job if they haven't seen what's underground.
My 2c : By your earlier questions i think you should be getting some quotes.

Stewart

[patty]

White bends are predominantly used for Communications Telstra etc Grey Conduit is medium Heavy duty used for "all surface area electrical applications Orange conduit is designed for underground usage

[rrich]

I can't address the code requirements because I'm sure that your code is different enough from ours that any advice from me would be worthless.

What I can do is to suggest some logical thought on the whole process.

The source of the electricity needs to get to the shed from??? (Perhaps the house? Perhaps a new feed from the power company?) Design the power entrance to the shed with this in mind. Here we would install what is called a "Subpanel". Typically a 100 amp breaker in the house or main panel feeds the subpanel.

Use the best method to get your main feed to the subpanel in the shed. I believe that you said that you are planning a timber structure with a steel roof and sides. Here we have something called romex which is electrical cable, typically two conductor plus ground inside a plastic outer jacket. It is legal for us to route this romex wire through walls without conduit. However we are required to put a steel nail guard where the romex passes through the timber frame. The intent of the nail guards it to prevent the home owner from hitting the romex when hanging pictures, shelves, etc.

Having done both types of wiring, it is much easier to route the romex through the unfinished walls than trying to install conduit. If you are allowed to use romex, I would suggest that method as it is so much easier.

Recent changes in the code here, require that romex be covered with some type of wallboard / sheetrock / plaster board on the interior of the structure. This includes sheds and garages.

[rileyp]

lol 100amp breaker.
Most houses in Australia have a 80 supply or less....
Romex=tps (thermoplastic sheath house wiring)
These drop in steel inserts for the wall frame sound like a good idea although do they have plastic bush ends on the edges of the insert?
Could you post a picture of one?
I hope you don't mind me hijacking your thread Com_VC

Cables installed below 1200 in plantrooms or areas where there is a likelihood for them to be mechanically damaged must be mech protetected in Australia.wg conduit cable duct top hat cover etc
Eg your shed at home around the walls and esp near the doors up to head height.

Please beware corrigated conduit is not to be considered mechanical protection as it isnt.

You can use grey bends but don't ask me the regulation.
hope this helps
cheers Rileyp

[rrich]

lol 100amp breaker.
Most houses in Australia have a 80 supply or less....
Romex=tps (thermoplastic sheath house wiring)
These drop in steel inserts for the wall frame sound like a good idea although do they have plastic bush ends on the edges of the insert?
Could you post a picture of one?

Rileyp

100 amps... I was afraid of that. Our 100 amps is about equavilent to your 50 panel due to the differing voltage distribution systems.

Ah, now I understand what TPS is... Thanks.

Please forgive the imperial diomensions. The nail protection plate is a 1-1/2 inch wide plate that slips over one of our framing studs or 2 x 4. The plate is about 2-1/2 inches long (think vertical) and has ears that allow it to be held in place with small nails. The plate has flaps about 1/4 inch bent parallel to the framing stud. What we do is to put the plate on the framing stud next to the hole for the TPS on the interior side of the framing stud. Then the plate is held in place with the small nails that are attached to the plate. After the wallboard is installed the plate is covered and undetectable.