Calling all electricians/people who know what the government requires:
Should control wires for 24V solenoids, be:
a) Single cored, be rated at 2 amps, single insulated
b) Run in the same trench as the water pipe
c) Be run loosely in the trench, allowing all manner of tree roots to grab and grow around them
d) Be broken by aforementioned roots, rendering said reticulation system useless
Why aren't they run inside conduit? Should they be?
The number of cores is going to be determined by the number of solanoids. We usually cabletie the cable to the pressure pipe then tuck it underneath. You could put it in it's own conduit if your really anal or if your running under a slab. How many solanoids you running? Ps I'm a landscaper, dont think i've ever seen a sparky put in an irrigation system.
I really enjoyed having to repair the cable after I dig through it to repair leaking pipes, it gives you something else to do in case you are a bit bored. I really like that idea of hiding the cable under or right next to the pipe. If it was in conduit I wouldn't have this great experience,
These are irrigation systems that people call me in to fix(plumber) as by this time the owners have lost faith in the original installers.
If the cable is under the pipes you basically have to dig thu the pipes to hit the cable. I don't think I've ever seen controller cable run in conduit other than under slabs ect.
, can do that quite easily if digging for another pipe (sewer or water)underneath the irrigation system and it is not known that the irrigation line crosses this trench, 
a more entertaining one for us is the nylon gas lines, especially when the have a bend in them and no marking/ caution tape in the trench. Now they are a whole lotof fun[}:)]
I would honestly say the exception not the norm in my experience. We just did a paving job where the first thing we had to do was smash out three big eucy stump. Couldn't do with a grinder as th water meter was right next to the stump. After two days of smashing whilst simultaneously being incredibly careful we got the buggers out. During the process we found the water and gas lines and the nextdoor neighbours teltra line running 90dgs across both of them. All of them 200mm down and no tape on anything. Just glad we found them all the good way not the hard way. Nothing under the soil surface surprises me anymore.
I'm still waiting to find the suitcase of cash down there. I know it's coming soon
i dissconnected my reticulation system 2 years ago.
plants are still going strong and the planety has been saved!
*insert superman theme now*
We had a bit of rain over winter in Sydney so Sydney water in all their wisdom have now lifted all the water restrictions. Aparently a couple of decent rains in the catchments now mean the climate isn't changing anymore. And after spending the last 5yrs making people put in rainwater tanks and convert all the irrigation to driplines ect they have now said we can revert back to the old ways that contributed to putting us in the sh#t in first place. Unbelievable.
Hmmm... so everyone does it that way? Unbelievable.
Maybe it's a cunning plan by the installers to get more work in a couple of years time or something.
*back to digging*
There's more money in water restrictions to be honest, with extra materials ect. After doing nothing but dripline for the last 5 or so years I believe the overhead systems work a he'll of alot better, esecially in sandysoils which is primarily what I deal with every day. Never in a million years did I think they would change the restrictions back. At least the world will be a lttle greener now.
Nebian, I would put it in conduit if your that concerned and don't mind the additional time and money. If not cabletie to the underneath of the pressure pipe and you won't have any dramas. In order to cut the controller cable you'll need to cut the whole way thru your pipes in which case you'll have a new swimming pool and the cut cables will be the least of your problems.
dont cable tie it tightly to the water pipe, leave it loose with extra folds of wire so if you have to repair a break you can pull a bit together rather than doing two joins.
Dont use conduit though use 12mm black poly, cheap as chips and run a length of string thru it at the same time so you can pull a new wire thru if nec.
Guaranteed you will do a better job yourself than any retic installer. Most (if not all) couldnt give a rats a+s what happens to it next week.
Put all the solenoids on a neat PVC manifold together where you can get at them instead of buried somewhere at random in your lawn.
Low voltage cabling is not required by law to be run in a conduit etc but it is always advisable to run it in a conduit of some sort in high trafic areas, walkways etc. Stones will pierce the insulation and the cable will corrode.
As for the size of cabling - it all depends on the length of the runs as the biggest issue with low voltage is voltage drop. Longer runs require heavier cabling.
Thanks guys for the advice.
I've already rewired all cables in the front garden in nice orange conduit, with inspection boxes over all solenoids.
I was just wondering if the guy who put mine in had done a dodgy job... it seems that it's the standard way of doing things. How it's supposed to last more than a couple of years with tree roots busily breaking any cables they can find is beyond me... but hey what would I know.
Irrigation is pretty much broken up into two categories, overhead and drip. Overhead ( which was killed of be water restrictions) is where the water is delivered in a more natural way, eg it flies thru the air and is bought down by gravity like rain does. Drip is where it is delivered slowly but for a longer duration directly to the soil surface relying on the surface tension of the soil particles to spread it sideways and down thru the soil profile. This is where I believe it falls short in sandy soils, bigger particles less suface area as opposed to say a more clay based soil. End result is the water travels almost straight down, creating wet "strips" as opposed to the more even moisture you get from overhaed irrigation or rain. Another downside is when you apply fertilizers to the surface of the soil it generally sits above the source of irrigation and thefore the nutrients aren't carried down with the water thru the soil to the roots. The fertilizer will basically sit there till the next big rain.
When you refered to single core ( in your original post) were you talking about using an individual wire? Eg of there was one solanoid you would have 2 individual wires?
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When i did my retic I just kept all my solenoids in the one place, (under the verandah deck), accessable via an access panel. Made a header of sorts then run the pipe, All 6 in one place, plus the high pressure one, it seemed to me the way to do it. Probobly run more pipe, but the pipe was cheap. The solenoids are within a couple of metres of the control. I couldnt understand running cable all over the garden and then burying the solenoids, didnt seem like a good idea to me.
some fascinating ( good and bad ) ideas there!
you shouldnt need to lay a single wire as even for 1 solenoid you need 2 wires. as an installer/ repairer i only use wire that is in an extracasing. so for 1 solenoid you have a 2 core wire , if its a long distance from the controller, consider a 3 core wire(1 spare wire for later years). ideally put all the solenoids in one place or a front garden block and a back garden block. Dont forget the MASTER solenoid,manual valve and the double check valve.the dCVand manual should be done by a plumber .
i usually use white conduit from the controller to the solenoid cluster. dont use cheaper black retic, somebody will cut it! doh.
nothing ruins your day like unearthing a bundle or red wires all going the same way, use the multicoloured stuff please
Nebbian, generally we use 5,7,9 core ( that is 5,7,9 individually insulated wires with secondary insulation around the bundle) , the more smaller individual wires the better as there's more surface area for the current to travel across. I've never had roots do anything to this cable ( or any cable for that matter, you must have some day of the trifids stYle roots happening out your way
and aranchini generally you'll put the solanoids closer to to zone due to pressure drop and you put the solanoids under ground in a box due to the fact that PVC isn't uv rated meaning in time it will explode under pressure. No more free advice
Sorry, one more piece of advice before I head back to the dole Que. If your putting any conduit in the ground make sure it orange as it will break down slower and it's harder to bust with a shovel.
