If you have a Holman 4/6/9 controller and the display looks ok, but it doesn’t seem to be working then the first thing to check out is whether the rain sensor display says ‘rain sensor wet’ or ‘rain sensor dry’.
If it displays a ‘wet’ message then it means that there is no 24v power going to the controller and therefore no power to operate solenoids.
There are a few things that could cause this:
1) check your RCDs in your meter box as if one of these has tripped then you won’t have power to the box.
2) check your fuse. Most likely a fault will have blown the fuse.
3) It may be that the transformer that converts 240V to 24V has died. Not much you can do here but replace the unit.
But before you call someone out do the ‘wet/dry’ check first!
I was working on a friend’s place recently with a strange fault that was proving difficult to track down.
The solenoid would come on and off intermitently. It would work 10 times in a row and then fail. There was power (27V) coming from the control box but at the solenoid the power varied between 22-26v according to my multimeter.
The power wire to the solenoid had been joined several times before it reached the solenoid and after eliminating any other possibilities (faulty coil/controller) I could only conclude that there was a problem with the wire run.
I ran a fresh wire to the solenoid and tested it around 20 times with no failure. It seemed that the wire was flawed somewhere between the controller and the solenoid. There were numerous connections and it wasn’t easy to find where the problem was so I simply ended up running a new wire.
So far so good…
This week I went back to a job I first looked at a couple of months back.
I stopped in on my way home to see why this particular system wasn’t working. It was late in the afternoon and more than I had time for so I declined to take the job on right then.
So when we got back yesterday I knew what we were doing.
I had already tested for power at the Master Valve and there was nothing there. However what was really odd was that there was intermittent power. I know because I brushed the fleshy side of my forearm across the wires and got a small boot. The power wouldn’t register on the multi-meter, although it did shoot up to 28v on one occasion before dying again and making me wonder if i was dreaming…
So the logical conclusion was that a common wire had been broken somewhere. Even when the master valve was turned on manually there was still no water going thru the system. We began at the controller and traced the wires thru a series of 4 different joins and eventually discovered a sliced cable about 30ml underground alongside the driveway. It looked like the edger had given it a beating.
The wire were joining occasionally hence the odd readings, but once it was all tidied up and rejoined the system was working perfectly again.
I went to a job today where the client told me that they were on a shared bore and that only one of their stations would come on. The pump would come on when the rear lawn was running but not on the other 3 stations… strange…
What was going on?
When I got there I also discovered that he had installed a new control box and wired it up himself. I assumed all this was done correctly, but after half an hour of testing various things it dawned on me that what he had done was wire the master/pump wire incorrectly.
He had mistakenly put the pump wire in station 4 and station 4 wire in the pump terminal thus meaning only one station would work. Once we reversed the wires everything worked as it should have.
The learning here is:
- always get the wires back in the right place
- if in doubt make sure you get the pump/MV and common correct. The rest is easy.
And if you ever re-wire your own control box and have just one station come on then consider that you have got the MV/pump wire in the wrong terminal.
Its easy to do!
I got a call to look at this retic system where the control box was displaying the ‘off power’ water droplet symbol. (see the left side of the display)
I wasn’t sure what it meant or how it got there and the manual didn’t mention it. A brief google search suggested it may be the box blowing a fuse and protecting itself against a faulty solenoid coil.
I called Scott at Total Eden and then he put me on to the tech heads at HR who weren’t totally sure either.
So I began to test it and discovered there was no voltage coming from any of the terminals. The fuse was intact and the battery was ok but the box just would not operate.
I attached a new control box as a test and it worked first time. The problem was in the box and whatever the source of the problem was, it had fried the whole box.
When the new one was installed I ran it thru the stations and it worked well on 1 & 2 but blew the fuse on station 3. Obviously this was the source of the previous problems and the coil needed replacing. As it turned out the whole solenoid was cactus and had to be replaced.
I repowered the Orbit box to see if the symbol might disappear but it was definitely a throwaway. So if you happen to see that symbol and your retic won’t work then chances are you will be looking for a new control box
Reticulation wiring that leaves the control box is not dangerous.
As a general rule if you feel anything when you touch the wires it will be a light buzzing in your finger tips. That’s because its low voltage – around 24v and it isn’t enough to hurt you.
The Control box has an inbuilt transformer that reduces the current from 240v so that any wires beyond the controller are safe.
NOTE: DO NOT TOUCH THE 240V WIRES INSIDE THE CONTROL BOX!
That’s also why wires usually aren’t laid in conduit. Most installers will tape the wire to the underside of the main reticulation pipe to protect it, but apart from that it sits free in the ground.
If you happen to chop thru some wires then you can simply rejoin them with insulation tape and all should work again. For some people wiring just isn’t their thing at all and its easier to call someone. If that’s the case then we’d be happy to hear from you.