2 Controllers with Munro Smart Pump Relays. Does it work? Yes / No?

I can’t seem to find a definate answer to the following questions - and wanted to see if I can get Yes/No answers - and any other suggestions regarding the Munro Smart Pump relay that allows 2 controllers to control a single pump/source. The Smart Pump performs other great features to save your pump too but I don’t want to get off track here.

Yes or No: Does Gen 2 or Gen 3 controllers work with Munro Smart Pump Relays without showing zone fault errors? (ie two controllers connected the Munro smart relay)

Yes or No: Has Rachio product / support / dev actually tested with the Munro Smart Pump Relays?

Yes or No: Has anyone fixed / found a work around for Zone Fault messages when two controllers are connected to the Munro Smart Relay Pump?

*** Background ****
I have been going through this effort for the past 3 years performing a lot of troublshooting:: measing voltage drop, rewiring all wirded connections, running new master value lines, working with Munro support/replacing their relay/testing their circuits, etc – Even thought all this effort - it seems that the Rachio controllers still somehow indicating a ‘Zone fault detected / master value may have wiring issues’. I am 99.99999 % sure at this point all my wiring is top notch / done correctly.

Bottom line: I think the 2 Rachio controllers are getting ‘confused’ by seeing each other being connected to the Munro Smart Relay (controlling the power to the pump, etc) - and causing the fault error. Is that possible?

What is happening I have 1 16-zone gen3 controller and 1 8-zone gen 3 controller connected to the Munro Smart Pump relay - with all heavy gauge wire and are all with acceptable voltage drop for the controllers and relay to operate (already been that path with Rachio’s great support teams and Muro’s senior engineer that personally look interested in helping me troubleshoot this). What is happening is that I get RANDOM zone fault messages - stopping the scheduled job or a manual job. It is completely random - as I have tried 1000’s of variations over these 3 years to isolate the problem - rewiring everything, trying different sequences of zone, turning on controllers in different orders, putting time pauses between running zones, making sure jobs are not trying to run at the same time, new replacement solenoids, etc…

I also say that because when this fault occurs – and it’s a lot: once every 3 or 4 cycles at least, if I simply keep restarting the job a couple of times from the app or manually from the controller, it eventually will works – but that usually takes 2 ot 3 faults first – but it will eventually work.

*** My Thoughts about a Solution ***
Through all of this – the error seems to boils down to if when BOTH controllers are connected to the relay, it produces these random fault messages. If only one controller is connected to the smart pump relay - and the other controller is physically disconnected from the Smart Pump Relay, then one connected controller works just fine never generating a fault. In my troublshotting, I have even alternated controllers - same results. I have even the upgraded both controllers from gen 2 to gen 3, tried the combination of these, etc… That was a pricey way to troublshoot - but same results. Bottom line – when both are connected – that’s when the fault errors are triggered.

Additional Considerations: Like I mentioned, I had the issues starting with my Gen 2 controlers - but when I moved to the Gen 3 controllers, I get A LOT more over these fault errors. Leading me to believe it’s something in their SOFTWARE reacting to a voltage/amperage issue triggering this message / shutdown when two controllers are connected to the smart relay. My theory is that controller 1 sees controller 2 over the relay – and that is causing the master fault error condition - and they lowered that threshold for the fault.

My gut is telling me there should be another system flag that Rachio needs to set / trap to deal with two controllers being attached to the Munro Smart Relay. I could be wrong on this – but I am reaching out because there doesn’t seem to be clear answers to questions on using 2 Controllers with the Munro Smart Pump Relay. Perhaps I am missing a setting somewhere (please tell me that is the case!)T

Thus my questions:

Yes or No: Does Gen 2 or Gen 3 work with Munro Smart Pump Relays without showing fault errors?

Yes or No: Has Rachio product / support / dev teams actually tested 2 controllers with the Munro Smart Pump Relays? (again two controllers connected the smart relay)

Yes or No: Has anyone fixed / found a work around for Zone Fault messages when two controllers are connected to the Munro Smart Relay Pump? (are they seeing each other and that could be causing the fault condition to trip)

Thanks for your thoughts and suggestions!

@AngryIrrigationMan - which model of the Munro Smart Pump relay is being used? The reason I ask is in a prior post it was noted there is a lower power drawn Munro model that did work. See ->

I’d also consider isolating the controllers from each other using a SPDT relay (approximately $7 on Amazon) as was diagramed/discussed in this post ->

If it is truly a current draw issue with the Munro device, then one could use two NO (normally open) SPST (single pole single throw) relays wired in parallel with each relay coil controlled by a different Rachio M terminal. The power from an external power supply (2 Amp +) would go through the Common/pole terminal on the relays with the NO term connected to the Munro pump start signal and the common/return from the Munro back to the external power supply.

So while I don’t work for Rachio, here are the answers to the three questions.

  1. I believe so with a low power draw version as mentioned in earlier in this post.

  2. I doubt it as I would think this would be a rare case for them to spend the time/trouble/effort to test.

  3. See the above solution to isolate the controllers from each other, with or without a beefier external power supply.

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@DLane A hearty thank you for your detailed reply! Your level of detail was the life-raft and sanity check that I needed - and at the same time made my head hurt! Also thank you for including the other threads as the diagrams were very helpful.

Bottomline: I think you hit the nail on the head - I am using a 220V pump.

With that in mind, I was wonder if you can expand on your reply as you stated the following as a possible way forward:

“If it is truly a current draw issue with the Munro device, then one could use two NO (normally open) SPST (single pole single throw) relays wired in parallel with each relay coil controlled by a different Rachio M terminal. The power from an external power supply (2 Amp +) would go through the Common/pole terminal on the relays with the NO term connected to the Munro pump start signal and the common/return from the Munro back to the external power supply.”

I have two questions:

First - is this the correct NO SPST:
https://www.amazon.com/URBEST-HH52P-Electromagnetic-Power-DYF08A/dp/B00NN5ABG2/ref=pd_cart_vw_crc_1_3/132-3164648-6791922?_encoding=UTF8&pd_rd_i=B00NN5ABG2&pd_rd_r=a6dedbcd-667a-48e5-8257-41a8e73ec429&pd_rd_w=oTDOV&pd_rd_wg=U6iv8&pf_rd_p=7b1a11cb-b9d6-4645-a52e-34c86ca37029&pf_rd_r=N4ZWA8XMJRE28N7WRQPG&psc=1&refRID=N4ZWA8XMJRE28N7WRQPG In case that link doesn’t work, it’s the “URBEST HH52P AC 24V Coil DPDT 8 Pins Electromagnetic Power Relay w DYF08A Base” from Amazon

Second - can you expand more on your quote as I get lost at the second sentence – starting with ‘The power from an external power…’ I think I have it – but I just hate letting the smoke out of these things :blush:

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@AngryIrrigationMan - you’re welcome! The current draw isn’t related to the current or voltage (a 220v pump will pull about half the amps a 120 volt pump will for the same size) the pump draws, but rather the current the pump start relay needs to close the relay and energize the pump.

Here is a Visio drawing I quickly hacked together.

That relay will work. I prefer a sealed unit like ->

Let me know if you have any other questions.

Again - YMMV.

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@DLane

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Many thanks as that was definitely helpful! So I ordered these relays and they arrived - just in time for me to have to head out a couple of weeks (sigh…).

I will work on that when I return but in the meantime, I do have a question: I am not familiar with relays enough to translate your Visio diagram into the actual 6 pin layout of the physical relay. I have been trying to do my homework on this and I found the following information about the relay but I can’t verify it is correct. “Pin pair 2 & 4 are normally closed; Pin pair 2 & 5 are normally open. Pins 1 & 3 are the 24V coil contacts.” Assuming this information is correct, based on your directions, my power source for each relay would run across pins 2 and 5, and then Rachio C/M across the 2 and 4 pins. Forgive me for not having the exact lingo down as I generally resort to simply getting a bigger hammer. But do I have that correct?

I have a feeling this sense of security I have at this moment will disappear when I open the box and start tracing wires in a couple of weeks but I look forward to that challenge! (gulp)

@AngryIrrigationMan - close. Here are the wiring connections:

Rachio C to Relay 1
Rachio M to Relay 3
Power supply lead to Relay 2
Lead from relay to pump start relay to Relay 5

and then the other side of the pump start relay trigger line back to the other line on the power supply.

There should be numbers by the pins on the relay (I think). If not number then NC - normally closed (pin 4), C - common (pin 2), NO - normally open (pin 5) and the other two would be for the coil. Also a ohm meter can be used to identify pins if necessary.

You’ve got this. Safe travels and have fun. We’ll be here if there are any questions when you get back.

Please post the results (success!) when it is installed and working.

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