Irrigation system electrical issue

The Dude With Herpes

I'm looking for some help with my yard irrigation system. A couple weeks ago (I think?), for reasons unknown, half the zones in our system stopped running at all.

I didn't notice until today and have spent a lot of time trying to troubleshoot the problem.

I've narrowed it down to an electrical problem, but I just don't know what exactly.

So yeah. A rundown of our system. 16 zones, split between 4 boxes housing several valves each (2 boxes, one with 4, one with 3 on the west side, 2 boxes one with 5 one with 4 on the east). The zones on the west side work fine. The valves on the east side, none will turn on. I tested each zone manually, and if I force a zone on by turning the solenoid, every zone flows normally. So, electrical.

I had to go out and buy a voltohm meter, but what I discovered was that the program box is sending out the correct power, and the valves are all mixed up between the breakers in the box, meaning that the zones on one side aren't on one breaker, i.e. the valves that aren't firing aren't setting off the breaker or busted a fuse, as the other zones still work fine.

I made some mistakes in testing because I was busy with a lot of other things today, so while I tested a couple solenoids, I didn't test each one individually and I failed to test the voltage at the valves. However I did rent a wire tracer/detector and for what its worth, when hooked up to the wires for the valves not firing, it detected voltage all along the line, with no break. I also redid all of the splice connections on the non-working valves to ensure that at least from that end they were all done correctly and with new waterproof connectors. Obviously I should have taken that time to test every solenoid individually, but derpdederp.

Didn't work.

I used the meter from the box to test the loops and all of the working valves showed the expected 30ish ohms, but nada for the unworking ones.

Here is where I'm confused: the lines are pushing voltage through to the valves, yet I get no reading from them as a circuit (I think that's right? I'm not an electrician, sorry), so presumably something is wrong with the common wire? I don't know how to test it individually, however. Could I use the wire detector in reverse, with the ground on the voltage wire (all unhooked from power obviously) and the voltage on the common wire to see if it is still pushing through voltage to the valves? Would that work? Could one (or more) bad solenoids be causing all of the valves to not work, simply by being in the same common loop? Are they that delicate and/or limited by other things on the chain?

I've only got a little time in the morning with the detector, but aside from that one thing I don't think it is useful anyway, as it doesn't seem like there is a break or cut in the line anywhere along the way (and there shouldn't be as we haven't done anything that would cause that). What I don't have is a ton of time to wait to fix it because it has clearly been awhile since those zones were watered, and our vegetable garden and fruit trees aren't being watered (I will start doing them manually if I can't get it fixed tomorrow morning). I'm just looking for any other possibilities I haven't thought of, from people who actually know more about this stuff, to ideally fix it before I have to call a lawn service who will probably both charge a fortune and take forever to get around to fixing it.

To recap: half the valves in our system won't turn on. They work fine physically if I manually turn them on. They are getting the right voltage from the controller and from at least the detector are getting the right voltage at the valves. Ohm meter gives nothing (technically OL, but that's the same as default so I'm not sure if it is actually overloading from something, or what). I haven't tested all solenoids individually, but am unsure one bad solenoid would cause a whole chain to fail.

Any ideas?

The Dude With Herpes

Well, it turns out it was definitely the buried wiring.

I don't know why or how, but somewhere along the line there must have been a short. I could get voltage at the valve ends from the controller, but if I checked the ohms it wouldn't read. So somewhere there was enough damage to short out the chain of valves, but not enough damage to actually cut voltage and power. We haven't done any digging or anything like that, so I have to assume it was either damage to the line already, likely from the shoddy work of our landscapers (I have a plethora of issues with the job they did) or the corn we have growing in the general vicinity of the buried wire has super-plant roots that managed to damage a line specifically graded for irrigation. :rotate: I don't know why a couple weeks ago there was no problem, and without any change that I'm aware of, was suddenly broken. Ah well.

For the time being we just have a wire running across half the back yard and all the wiring not in the valve boxes (but properly protected regardless) that will just be that way until I can find the time to bury the new wire and re-run the ends through the boxes and up to the controller. Regardless of the ugliness (which we will only see, fenced in backyard) it all works now, so hopefully nothing was unwatered long enough to kill them. Its the trees I'm most concerned about.