Max safe current draw, concurrent run groups

[m100psi]

After running OS for about 9 months, I just today noticed that running all 7 zones simultaneously draws ~3.5A. I guess my 650 mA power supply did all right for itself making it 9 months in these working conditions before finally failing this morning. So a few questions in the aftermath…

I understand the power supply needs to be rated for drawn current, but what current is safe for the OS module? Is it fused, or does it have other over-current protection?

Is it possible to set up concurrency groups, so 2-3 zones run at once?

The AC/AC adapter sold on the OS site is only rated to 500 mA. Any recommendations for higher current 24VAC supplies? They don’t seem to be common.

Thanks,
Matt

[Roger]

After burning up several transformers (due to a short in a valve), I switched to one of these: https://www.amazon.com/dp/B083R621RV. Overkill, for sure, and I fused the circuit to OS at 1 amp. I don’t know what the safe current for the OS module is. For the one situation in which I have more than two valves in a zone, I added a small relay that switches current from the same transformer, but fused at 4 amps.

Rog

[Ray]

While the firmware doesn’t limit the number of valves that you can turn on at the same time, I would say that simultaneous zone runs should be limited to 4 or less. Running a lot of zones at the same time can significantly increase the current load of the system. If you do want to run many zones at the same time, adding an external relay board would be the best since you can then use very thick wires to allow much more current to flow through it.

[m100psi]

Thanks guys. If I wanted to run 4 zones at a time, is there a way to set up concurrent zone groups or would I need to uncheck “sequential” on all the zones, then set up separate, duplicated programs for the different zones I want to run together?

Matt

[Author]

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