- 2nd Jul 2004, 09:43 AM #1
Same trench: Electricity and water ???
How much can I legally squeeze into one trench and what are the required depths and seperations?
I have to run:
- 2nd Jul 2004, 05:12 PM #2Registered
- Join Date
- Aug 2003
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.
- 2nd Jul 2004, 05:30 PM #3
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.I like cats but I couldn't eat a whole one :
- 4th Jul 2004, 07:03 AM #4
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.
- 4th Jul 2004, 08:32 AM #5Novice
- Join Date
- Aug 2002
- Lakehaven, NSW, Australia
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
- 4th Jul 2004, 10:17 AM #6
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.
AllanAlways willing to learn
- 4th Jul 2004, 11:23 AM #7
Fantapantz I've got some regs for you -a little involved to post here maybe mail me if still required,
AllanAlways willing to learn
- 6th Jul 2004, 10:59 PM #8
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.
- 8th Jul 2004, 01:12 PM #9
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???
- 8th Jul 2004, 09:39 PM #10
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.
- 9th Jul 2004, 11:06 AM #11
Obstructions to doing it rightOriginally Posted by Fantapantz
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 !!
At least people in this group have decided to buck the trend and share knowledge. I admire your openness.
A society grows great when old men plant trees whose shade they’ll never sit in. (Greek proverb)
- 9th Jul 2004, 11:21 AM #12
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.
- 10th Jul 2004, 02:49 AM #13Direct quote from soundman Don't forget to sand the trench.
- 11th Jul 2004, 10:12 PM #14
Ahh that depends on what sort of finish you are looking for.
- 16th Jul 2004, 12:05 AM #15
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.
- 16th Jul 2004, 02:41 AM #16
I did this course so I could get my cabler's licence... $780... :mad:
(Knocks dust off course notes) (talking data here by the way, but…)
Bug'a... sez fug'all really, I quote....
AS009:2001 126.96.36.199 Shared trenches with other services
188.8.131.52.1 Where customer cabling is installed in a trench together
with conduits, pipes or cables supplying services for utilities such as gas,
water and electrical power, physical separation between the customer
cabling and other service(s) shall be as required by the utility concerned.
Useless as tits on a bull...
reminds me of a 3 stooges show...
everyone's pointing at everyone else...
Digging further, I've come up with 1998 copy of a Telstra book of rules....
Again, this is for data (communications) cable...
It even has all the colour codes for the 'pipes' or conduits for all the services.
In a nutshell, it can be in a shared trench with power less than 1000V ac or
water as long as it's in a white conduit & has a 100mm separation from either.
The damned book doesn't mention the separation between power & water
in a shared trench so we are no further really other than to say it seems
to be possible if the service is the correct distance under the ground &
contained in the correct coloured conduit so....
Here we go.... (there are some finer technicalities but...)
Power, Orange conduit, 500mm minimum below surface.
Communications, White conduit, 300-500mm urban 450-600 rual.
The second figure is for under trafficable areas.IE 500mm under an urban road.
Water pipe, Green conduit, 225mm minimum below surface.
(drinking water has an undisclosed supplementary colour )
From all that waffle, if you stuck your water at least 225mm under ground &
stuck the power in an orange conduit at least 275mm under that,
you'd be pretty safe I'd reckon.
Hope that helps....Cliff
...if all you have is a hammer, everything looks like a nail...
- 18th Jul 2004, 12:28 PM #17
The other problem is they keep changing things.
in the old as3000 trench depth was 600mm traficable & 300 untraficable.
I got sick of updating my austel regs book at one time the monthly alterations were like 20 to 30 pages.
the old AS3000 anybody with a bit of time & decent comprehension could read the book & understand. now since its aligned with the european style of standard and all the usefull tables & apendicies have been left out you need to go on a course just to keep up.
- 19th Jul 2004, 12:41 AM #18
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