Pump start relay suggestion

Post by Feldazin on Jun 10, 2024

So I installed a Rachio 3 controller, it replaced a Rainbird wifi controller, I have a Hunter PSR 52 pump start relay that powers on my pump to draw water from a pond, I will attach pictures of my pump specs. I believe its wired 110v because the hunter is 110 5hp or less pumps and my pump is 2.5 Hp. So im having the issue where the Rachio cant give enough power to the relay to kick the pump on, iv round several threads speaking on this because its a known issue with the psr 52. I have seen people use a different relay model number

MPSR242W22

But this relay wont match my pump… since im 110 2.5 hp. Im looking for a known relay that works 110 for a 2.5 hp pump and obviously responds to Rachios pump on signal. Any suggestions are appreciated, i did find one i will link if anyone can let me know if it will work? Thanks

Post by DLane on Jun 10, 2024

@Feldazin - another way to handle this is to get a separate 24 VAC power supply that will power the pump start relay, wire it through a single pole single throw normally open relay switch (SPST NO) (one side of the power supply goes to the pole terminal on the relay, the other side of the relay (NO) goes to the existing pump start relay and the other line of the pump start relay goes back to the new power supply) and have the Rachio M terminal go to the new relay’s coil and then the other side of the coil to the Rachio C terminal.

Post by Feldazin on Jun 10, 2024

@DLane could you point me in the right direction of some materials for this?

Post by DLane on Jun 10, 2024

@Feldazin - Relay - Amazon.com or https://www.amazon.com/HEATING-SPST-NO-APPLI-PARTS-APFR-290/dp/B01N7AHEVT

2. Power supply - Amazon.com

Post by Feldazin on Jun 10, 2024

@DLane thank you for your time looking into this. Do you know if the k rain relay i linked would work?

Post by DLane on Jun 10, 2024

@Feldazin - No, I don’t believe so. From the K-Rain specifications:

The inrush current is 1.48 amps, which is more than the Rachio power supply supplies (1 amp).

Post by Feldazin on Jun 10, 2024

@DLane thanks. Iv got some of this wire left over from a project, will it work for the adapter? Amazon.com

Post by DLane on Jun 11, 2024

@Feldazin - yes that wire will work.

Post by Feldazin on Jun 11, 2024

And just to be clear, will this relay work in place of the hunter and this work around? Says max hp 2 on the pump, i believe mine is 2.5…. Seems like a lot of them cut off at 2. I need a relay that responds to 1 amp or less to start but also is 110 and powers at least 2.5 hp. Not sure if could squeeze by with this one or melt things down. Munro StartBox 2-Wire Decoder 24V Controller - 120V Pump

Post by DLane on Jun 11, 2024

No. This solution will work in conjunction with the existing pump start relay. It replaces the power from the Rachio Master valve with more amperage.

Post by Feldazin on Jun 11, 2024

@DLane Understood, last question hopefully.

In the application settings which option will i choose after installing the new relay?

Post by DLane on Jun 11, 2024

Choose Well or Pump Start Relay.

Post by Feldazin on Jun 11, 2024

Thank you for all your advice!

Post by Thomas_Lerman on Jun 11, 2024

@DLane: I actually have a Hunter PSR hooked up to my Rachio. According to valve monitoring, it draws 225mA and is marked as good. The highest of the valves is at 184mA. I am mostly curious about your solution in case mine drifts to where it is overcurrent as well as being able to understand in case I help someone else. Basically, are you suggesting that Rachio triggers the smaller relay that has a better power supply that then triggers the PSR?

Post by DLane on Jun 11, 2024

@Thomas_Lerman - correct. With it being a separate power supply, it won’t cause the Rachio to “brownout”. Early on I made lots of recommendations for relays to solve various problems. Search for SPST or SPDT to find those responses.