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Friday, June 9th 2017, 2:04am

Recommended Pump Start Relay

I need to buy a new pump start relay.
I have the following pump & controller:
  • STA-RITE Model DMMG-42L - 2.5 HP - 115v - 60Hz - MaxLoad Amps 24/12
  • Orbit 57900 panel sprinkler system

Could you please recommend a relay should I buy?


Supreme Member

Posts: 5,014

Location: Metro NYC


Friday, June 9th 2017, 7:03am

Probably no recommendation is possible. If your pump was running on 220 volts instead of 110, the lower running current might allow for an Irritrol SR1, with its 20 amp rating (and yes, the 'horsepower rating' of the SR1 is only 2HP, because they assume a starting current twice that of the running current)

Edit - There is a Rainbird product that puts two relays in a control box, with a heavy-duty power relay being actuated by a small "ice-cube" relay. The small relay works on modern low-power controllers (which is almost all of them, these days) and it switches the 40 amp power relay. Note that 2.5 HP is more than the 110 volt model is rated for, in peak horsepower, so you might want to go to running the pump on 220 volts, and gain some peace of mind) - note that there are two models of this product, because the power relay is running on the pump voltage, so they have to match

{note to the curious ~110, 115, 120 are all interchangeable when describing household line voltage}

This post has been edited 2 times, last edit by "Wet_Boots" (Jun 9th 2017, 2:12pm)

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