lawn sprinkler control unit repair

Great analysis! It always amazes me when someone with experience can look at a situation and know, right off the bat, what the trouble is. Any ideas on how to gopher-proof a sprinkler installation (not included "Caddyshack" sorts of solutions! (-: )

-- Bobby G.

Use hardware cloth to wrap 5 sides of sprinkler boxes before burying. won't last forever, but it helps. Hardware cloth is heavier than chicken wire, so does last longer.

Wires... conduit is the only way, and usually not worth it.

sdb

I already answered that a few days ago. Put down chemicals to kill lawn grubs and the gophers will depart for ...er, grubbier pastures. No kidding, friend. That's what we did and we haven't had a gopher hole since.

That sounds as if you have a serious, multi-wire dead short to the common wire at some point. While I think you've proved the buried cable is bad, if you wanted to be 1000% sure you'd need to repeat your test but also look for unintentional continuity on all wires.

I'd do it with a long piece of speaker wire to perform what's commonly called a loop back test. At the valve, clip your tester's leads to wire 1 of the head and to your length of speaker or bell test wire. Run the test wire back to the console and jumper it to the disconnected end of wire 1. You've created a loop consisting of only your meter, the questionable wire and the (hopefully) known good speaker wire (test it for continuity before using, just to be sure).

Now comes the important part of the test, and what you I believe you did, but missed the implications of the first time around. You must take the meter lead off the wire 1 and then test each other wire at the sprinkler head end in turn. This is the test that will tell you if the wires are shorted somewhere underground and which ones are shorted. Any other wire that shows voltage would be getting it through a short circuit.

So, you should have very low ohms (the light lights up) if the wire is good when testing ONLY wire 1, and infinity (no light) when testing each other wire in turn. After doing the "sweep" of the other cables, go back to console, connect the speaker wire to wire 2, go back to the head, insure that wire 2 has continuity and then connect each of the other wires in turn to determine if there are shorts between the individual wires. In this test the light should light up only for one wire at a time. If you do the continuity test for wire 3 and wire 5 or wire 2 also lights up, it's shorted.

-- Bobby G.

I hate for this saga to go on and on, but........... here goes

1) disconected all the wires at both ends ( control box and valve box) 2) Had someone, connect one at a time each colored wire to the common at the valve box, while at the other end I tested the same color one at a time to commom with a continuity tester. I got a light on each of the five colors, telling me I think that wires were OK ?? 3) but what confuses me is that I also got a light between each colored wire and common when they weren't connect at the valve box end. 3) So I hooked up just one wire and common to a good solenoid and control box, then tried to turn on at control box, fuze immediately blew?

Need a little more advice if you guys are still out there.

Paul

You also need to do the same test with all the wires disconnected at BOTH ends as I described in my earlier post below. If you test at one end with all the wires disconnected and not touching each other at the other end and see continuity between ANY two wires, then you have a short in the cable and need to replace the cable or at least find the damaged portion and repair it. If all the wires are good and you only see continuity when they're connected as in your latest test, you might have a fried controller.

If you put in a new fuse, turn on the controller and turn each zone on one at a time with NO wiring connected, the fuse will blow when the shorted zone is selected or even sooner if the short is before the zone seletion. New controller is the answer there.

Let us know what you find!

From: snipped-for-privacy@comcast.net snipped-for-privacy@comcast.net

Heh, so do the spiked guillotine traps.

Grub management presents it's own difficulties in that insects, worms and the like are useful in helping keep the soil healthy. But given Bob's in Florida I'm sure he's got a whole different set of issues than I've got up here in DC.

Not really. I just send a monthly check to the lawn maintenance outfit and it's their problem. :^)

It works, I've done it. Keeps both the gophers and moles away. A .22 with short rifle ammo tends to reinforce the point. (They sound like a loud air rifle, but much more effective)

-John O

Bruce-did this check and all the stations went on and the fuze never blew, so I'd say controler is good.

Then did a variation of what Bobby G recommended. I ran a 2 strand bell wire from controler, one station at a time to the corresponding valve. Then tested. In each case the valve operated and water flowed! So some part or all of the underground cable is bad. So tomorrow off to Home Depot to get a new run of cable and install it. Any suggestions on installing the cable? Will run inside the garage and then an underground run to the vavle box. Current cable is not in conduit or PVC, is that somethng you all recommend?

Paul

Sprinkler wire (18ga solid copper) is designed for direct burial but conduit is always better. Just use some half inch schedule 40 PVC and you'll proabably never have another problem. The conduit is small enough that installation, which doesn't have be too deep, isn't much more work than running the plain wire.

From: snipped-for-privacy@comcast.net snipped-for-privacy@comcast.net

Just to close this out, I want to thank the comp.home.automation gang for all your help and patience on walking me through this problem. The internet community and newsgroups are a great resource and an underappreciated byproduct of internet technology.

Paul

Glad to have helped.

From:pak snipped-for-privacy@yahoo.com