Help with Electricity 101 please

[bbruck]

I have added a couple new zones for eFlora and can't get them to work. Here's the situation...

I asked the irrigation installer (who can no longer be contacted sigh) to find which wires could be used for the new zones in a box in the back yard - and the in the wire bundle in my garage. He identified an unused black and brown wire. When wiring them to the new valve and then the eZFlora, the valve didn't open. Not surprising since I didn't read any voltage at the valve - though I did at the eZFlora itself.

So I disconnected everything from the outlet and disconnected the two wires from the ezFlora and at the box in the yard, and shorted them together in the garage.

I've never seen this happen before. The digital meter - which naturally started with a reading of 1 - went up to about 1.16, then slowly went down to about .56. I scraped the wires and found that it slightly more quickly went down to about .48. But it never read anything close to zero. And it would take 10-15 seconds to reach the final value.

I sang "stewball was an electron" to the wires, thinking that perhaps I had slovenly electrons, but it made no difference.

I have a bad feeling that the wiring is just old and tired and needs to be replaced - but it works perfectly well for the 11 existing zones - that's what confuses me.

 

[pete_c]

After the sprinkler company had installed my system I labeled and re-arranged all of the wires in the cluster / zone watering so that it made sense to me with the legacy rain-bird controller. (did the same in FL). There was no logic at the time in the wiring of the zones (IE: zone 1 was in the front of the home and zone 2 was in the back of the home). I rewired my zones in a clocklike fashion from the front to the other side of the home. It actually took the sprinkler company more time to "wire" up the controller than to install the lines. (6 guys doing the runs and 2 guys wiring it up) (odd?)

Disconnect the one wire running to the valve on one side to the box on the other side. See if goes to ground or shorting out against another wire in the cluster?

In FL this past December I had issues relating to sprinkler system there. Initially disconnected all the control valves and tested all the wires individually one by one (PITA) (panic had set in because the run was over 75 feet under the drivewave to the opposite side of the house).

Prior to testing noticed the 24VAC transformer had gone bad and the internal Rainbird controller fuses kept blowing.

I ended up replacing all the valves in the box as they were shorting out internally causing the issues at the controller. Actually ran out of time and just purchased the valves and contracted a company to replace the valves.

I would check the single wires for the new valves to see if they short to ground maybe? Sounds like you've done this

If you have more wires in your cluster then use one which you know to be good. If not then I guess run new wires.

In the MW I have 10 zones (switches-valves) (10 plus 1 common) plus rain switch (2) =13 wires and I have a two wires still free making a total of 15 total wires run plus a separate pair of wires in their own jacket (never used)=17. Now thinking about it I should move the rain switch over to the separate jacketed pair of wires (as its also shielded).

How many wires are in your main sprinkler cable? Box (s) to controller?

 

[BraveSirRobbin]

You can find which wires go from your garage to your box by measuring resistance. If you know of one good wire use it as your 'standard'.

Now take the meter and place it in the 'ohms' scale. It should read infinity or possibly "OL" or something like that. Now short the leads of the meter together and you will see the reading go to near zero.

At one end of your "standard" wire, say the garage end, tie it to one of the meter leads. Then selectively go through each wire for testing by jumpering one of the wires at your box end to the standard wire. Then take your free meter lead at your garage and go through the wires until you see a reading of near zero. Be aware that you will be reading the resistance of the wires which should be a few ohms. Do this for each wire until you have them all identified.

Then, make sure all the wires are disconnected at each end and not touching any other wires. Now at one end (say the garage end) go and measure between all the possible pair combinations and make sure you keep reading 'infinite' on the meter. Make sure that your fingers do not come in contact with the tips of the meter as this will influence the reading. This test will show that you have no 'shorts' between any of the wires in the bundle.

Again, make sure you do the above tests with the wiring disconnected from any voltage source.

 

[JimS]

Sounds like an open in the wiring somewhere - maybe not completely open but at least a poor connection. Are there splices/valve boxes/etc between the controller and the valve? The way I have seen sprinkler wiring done is to run the wires to the first set of valves and cut only the wires needed to connect the valves at that location with the remaining wires going to the other boxes. The white is usually used as common - the white going to other valve boxes is connected to the incoming white and the valves. Could be the wires you are trying to use were cut at another valve box but not used. It may help to determine if the brown, the black, or both are open - with the power off you could short each wire to another wire that is known good and measure the resistance to see which one is bad. Or use an unplugged extension cord as the return wire between the box and controller to test. Look in the other boxes and see if the wires you are trying to use are cut or damaged. The nice thing about using an extension cord or other temporary wire for testing is that you don't have to disturb the zones that are working.

Finding breaks in cable runs is difficult but they usually are where other things are happening to the wire. Making a sketch of how the rest of the wiring runs may help.

 

[bbruck]

Thank you both for your quick replies.

And it WAS wiring 101 - BSR you hit it with your last - I was holding the contacts together while sitting in the grass. That's why I got those funny slow readings.

In fact, I have no continuity at all - the installer who enabled the new wires obviously didn't check to see if they were actually going anywhere. I'm simply going to run new wire as suggested.

 

[signal15]

You could get a tone generator to make sure you're messing with the wires on the other end that you think you're messing with. Just hook the generator to one end, and use the inductive tester on the other side to find the right wire.