Same trench: Electricity and water ???

[Fantapantz]

How much can I legally squeeze into one trench and what are the required depths and seperations?
I have to run:
Electricity
Stormwater
Water
Communications

Ta

[ozwinner]

Im fairly certain the power MUST be in its own trench.

How would you be if you were digging to fix the communications cable, and you dig through the power cable.:eek:
Same with gas.

Al

[morry]

I have about 110 m of trench from the road to my house that has to go in soon and was speaking to my cousin who works for Country energy and he advised that my power and coms could go into the same trench but seperate conduits and each seperated by about 150mm. The power being at the bottom at 600mm deep. Not sure what the standard is in Qld though. Makes sense to me as if im digging all I have to avoid is one straight line and not a grid of services.

[Fantapantz]

I've been told by different people that they have multiples in the same trench. The most being electricity communications and water. He couldn't remember depth and seperation details.

[DarrylF]

You definitely have to separate electricity and comms by a reasonable amount or you'll get interference - 150mm should do it I think. Same trench should be OK if you do it right.

Personally I wouldn't put the water or stormwater in the same trench though. At some stage it's very possible you'll have to dig up the stormwater (tree roots, blockages etc), and having a trench full of water also containing your power & comms is not such a good idea

[Sigidi]

Fantapantz,

according to building regulations (and I'd say common sense) you have to have seperate trenches for electricity and water - i'll hunt up the specs for you and post later. As for comms previous info sounds very good wrt elec and comms interference.

Regs forthcoming,

Allan

[Sigidi]

Fantapantz I've got some regs for you -a little involved to post here maybe mail me if still required,

Allan

[soundman]

Same trench for various service is prety routine. But there are very specific requirements for seperation and various ways of achieving same.

All the different regulators have their rules & you have to copmpy with them all.

one common method is to dig the trench the required width to seperate the coms & electrical putting them in the bottom on oposite sides of the trench. then part fill the trench for the required sepeartion from the water above. lay the water supply & fill in.

this will often mean a trench deeper than required for the individual services.

This in its self may not be practical in many cases.

After all once the trench is filled, its all the same ground.

Some authorities may be soo very fussy about prooving the seperation it may not be worth the trouble.

I may be proven wrong, but from my understanding of austel & as3000 its all about seperation.

[Fantapantz]

Went into the council and asked the building compliance officer who said he couldn't tell me about the electricity because that would make him legally liable so i had to ask energex...........

He could tell me about the plumbing part but. Reticulation has to be 225 deep, stormwater can be wherever you want. there has to be 100mm seperation between reticulation and electricity. That was an Australian Standard, he said Energex may have different requirements.

As for communications I'd have to ask Telstra..........Who says I'm putting in a bloody telephone anyway???

[soundman]

Going 600 deep with the electrical & coms should be ok. cant rember the clearance between the coms & LX.

Electrical regs set the depth of the trench, austel regs specify the clearance for the coms, plumbers are less fussy.

Just remember you may need to dig it up someday!!!

Don't forget to sand the trench.

[HavinaGo]

Went into the council and asked the building compliance officer who said he couldn't tell me about the electricity because that would make him legally liable so i had to ask energex...........

He could tell me about the plumbing part but. Reticulation has to be 225 deep, stormwater can be wherever you want. there has to be 100mm seperation between reticulation and electricity. That was an Australian Standard, he said Energex may have different requirements.

As for communications I'd have to ask Telstra..........Who says I'm putting in a bloody telephone anyway???

steam on :mad: :mad: :mad:

Ain't this typical of the Australian scene ... you try to do the right thing and it is impossible to find the details of what you should do. Seems to be a stack of secret clubs ... full of people with bats to hit you with if you get it wrong!

I must say that I admire what I have heard about the New Zealand system, and even the UK system for electrical work ... provide the information, let people do their own work BUT inspect it.

What happended to the concept of making information available to give those trying to learn a chance !!

steam off



At least people in this group have decided to buck the trend and share knowledge. I admire your openness.

[davo453]

I recently built a house in WA, We put the power and phone in the same 80mtr trench with no consideration for separation. The phone line was a shielded multi core cable (I get 54k on a 56k modem which is quite normal).

Water I don't know (have to find out though for another reason) we are on tank water here........

Sand in the bottom of the trench is a must on hard ground.

Dave

[Fantapantz]

Direct quote from soundman Don't forget to sand the trench.

What grade of sandpaper do I use???

[soundman]

Ahh that depends on what sort of finish you are looking for.

[soundman]

Ive just had a look at the current AS3000 ( electrical) it reveals the following.

minimum burial depth in soil is now 500mm ( was different)
conduits of electrical and other services may be side by side (in contact) in a common trench under certain circumstances.
in hard ground electrical services must be laid on a 50mm bed of sand with 50mm sand covering.
cherrs