Opensprinkler3.0 DC – Faulty output and pump start relay problems

[samw]

Hi,

I have been running a DC opensprinkler on 24VDC without realising that it was supplying the full input voltage out to the solenoids.

I mistakenly thought it internally regulated down to the appropriate dc voltage needed.

This has resulted in one solenoid coil overheating and going short circuit, which in turn has lead to a blown output on the sprinkler controller. This is something I can live with as I have a couple outputs spare.

However, I have installed the supplied 7.5v DC adaptor which will operate any of my 24VAC sprinkler solenoids one at a time, but will not operate my master pump start relay at the same time.

I can activate the pump start relay by itself no problem, and then energise a solenoid afterwards, but it appears the controller is unable to provide enough power to energise both the relay and solenoid simultaneously. I have tried a 12v supply which will drive everything fine, but would prefer to run the lower voltage to avoid possible coil burn outs again.

Is it possible to introduce a delay so the master station energises a second before a solenoid is energised? This should solve my issue.

Thanks
Sam

[Ray]

At the moment you can only energize the master a few seconds after the first zone (using the so called Master On Adjustment option). You can’t have Master energize before the first zone. There are a couple of work-arounds you can try:
1. Perhaps the 7.5VDC adapter isn’t powerful enough (it’s only rated 1amp). You can try to get a 2amp one (or if your 12VDC supply works, it should be ok, yes the holding current is a bit higher but people have used 12VDC to directly drive their 24VAC valves for years without problem). If you want something in between, try 9VDC.

2. There is a work-around to introduce a delay for master zone. That is to use a dummy zone. To do so, let’s say your master zone is zone 1, and let’s make zone 2 a dummy zone, which means you don’t connect any valve wire to it. When you set a program, schedule zone 2 together in the program, for a few seconds. This way, master zone will turn on together with zone 2, but since zone 2 is dummy, nothing will happen, and when it comes to zone 3, master is already on, so that solves the ‘introduce a few seconds of delay’ request.

[samw]

Thanks Ray, I will give your suggestions a try.

[Author]

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