SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Thank you, Wet_Boots. I've just been browsing the site and came upon the detailed description of the various cross-connection prevention devices here:

http://www.sprinklerwarehouse.com/articles.asp?id=187


I'll let my neighbor know about the recommended upgrade. I thought I was going over there to plug in his timer or replace a solenoid. Now I know a lot more about irrigation than I ever dreamed I would. Not quitting the day job, yet, though.

Thank you!

SD

your AVB is something of an imposter - a lot of them get installed where a PVB should be

the actual approved application of the AVB is one for each zone, downstream of the zone valves

Thank you. The order of devices you've given makes sense. I was surprised to find the master zone valve upstream of the AVB, because it seems logical to have the cross-connection prevention device as the first device in the chain after the main system shut-off. My question was about the differences and advantages of a PVB over an AVB.

SD

the preferred order of pieces in the water chain is PVB - master valve - zone valves, because it is best to have the PVB pressurized 24/7

The benefit is keeping your and your neighbor's drinking water safe to drink. And, yes it should be done by a licensed professional.

OK, what is the benefit....reliability? Is that change something that usually requires permitting by a licensed irrigator?

SD

You should complete the repair picture by replacing the atmospheric vacuum breaker with a genuine Pressure Vacuum Breaker.

Wetboots, thanks for your thoughts on the wiring foul-up. Yesterday, I took a shovel and dug some more around the vicinity of the valves I had traced earlier...scraped off the lava rock and pulled back the plastic liner. Found the master and all four zone valves close together. Not quite a manifold arrangement, but they were close. Master valve was upstream of the AVB and had a very corroded solenoid. Manually turned on the master to verify flow to the AVB loop. Based on the low resistance readings above, I thought that wires #2 and #6 might be the master control and common. Cut the wires at the master and used a 9v. battery to verify. Sure enough, #2 was the common and #6 was the control wire for the master. Once I had the common and master verified, I just used trial and error to locate the remaining wires in their proper terminals on the timer. Had my son help listen for clicks at the solenoids. Still have a couple of valves that are sticking open, but the master is shutting off now and we'll get the others sorted out with new parts or a cleaning shortly. These are old Rainbird valves, round cover, roughly 4" in diameter on 1" pipe. Single thumbscrew on the top center with a bleeder in it and a metal rod attached....about 2 1/2 inches long. The wiring was all red, no white wire to identify common. I hope this thread might help someone else who might encounter a fried valve solenoid and fouled up wiring at the same time, as we did.


Thanks again, Wet Boots!

SD

You can always work backwards by connecting a battery to the wires in the field, and checking the controller wiring for voltage

I thought the same thing, Wetboots. So before I left I attached both 2 and 6 to the common terminals(there are two on this controller) and hooked the others to the zone terminals, then cycled through manually one by one....still no water to the AVB .

skintdigit