Replace Rainbird ESP-6 which has a transformer inside

post by leilobound on May 9, 2023

Hi, I’m trying to replace my Rainbird ESP-6 sprinkler controller with Rachio 3. I noticed the Rainbird controller has a small transformer inside (120V to 24 Vac).

I’m not sure if the transformer is part of the Rainbird controller as I haven’t actually uninstall it. I just opened to controller panel to see the inside and noticed it.

Assuming the transformer is a separate thing (and just happen the Rainbird inside has enough room to for that transformer), Is it possible to reuse that transformer for my Rachio 3 ?

post by leilobound on May 9, 2023

Here are the images of the Rainbird ESP-6

post by leilobound on May 9, 2023

More

post by Thomas_Lerman on May 9, 2023

It looks like it is part of the Rainbird controller. How would you reuse the transformer when it inside the Rainbird box? It would be possible, but the Rachio uses a barrel connector instead of wire terminals for power input. It looks like the Rainbird box is inside (possibly garage) and with sheetrock walls. It is hard to tell, but kind of looks like a power cable attached to the bottom (it is an extension cord or something else?). If so, is that plugged in? If so, I would just plug in the Rachio. Otherwise, I would suggest you or an electrician replacing the cable with an outlet box, maybe even surface mount, for the Rachio to plug into. Other options probably exist.

post by leilobound on May 9, 2023

Thank you @Thomas_Lerman and @tmcgahey !

The Rainbird is installed inside the garage.

I’m not sure what is that angled pipe thing that is connected to the bottom

That pipe seems to be connected to the transformer unit which has the two power cables coming out of it and connected to the two 24 VAC.

IIUC, to replace with Rachio3, I still need a transformer - correct?

@tmcgahey, for the outdoor box that you recommended, does it contain a transformer? And also, I assume it can also be installed inside correct?

post by leilobound on May 9, 2023

Forgot to include one more picture

post by Thomas_Lerman on May 9, 2023

Yes make an outlet out of the 120 volts from that pipe, plug in the rachio wall work, and then plug the barrel connector into the rachio. Definitely do not try to put 24 volts onto those terminals.

post by leilobound on May 9, 2023

Thanks.

I already have a wall outlet nearby. So I mean I don’t need to use those two120 vac wires from the pipe - correct? Or perhaps those two wires are dedicated for the sprinkler controller so I should stick to them?

post by Thomas_Lerman on May 10, 2023

Oh, I see. I would likely use the already existing outlet. I do wonder if the wires connected through that pipe is going to the outlet. You might be able to check it out when you disconnect the Rainbird. I would just make sure you take care of those wires properly.

post by leilobound on May 10, 2023

Thanks @Thomas_Lerman.

I recalled they were separated because I have a switch that can turn off the power of wall outlets in garage except power to the Rainbird.

So I may want to use those two red wires coming from the pipe. Probably buy the Rachio outdoor enclosure box since you guys mentioned there is a built-in outlet where I can hook up the wires from the pipe to the built in outlet.

post by Thomas_Lerman on May 10, 2023

You definitely need a hot and neutral, if no ground is supplied that is probably okay. If both of the wires are red coming out of the pipe, I am not sure which is which. That would be wise not have power dependent on a switch hike that outlet is.

post by leilobound on May 10, 2023

Thanks for the advice.

I think the green one is neutral. The dark bare wire (coming out from a hole above the transformer) may be a ground wire, but not sure.

The two red wires from the pipe (through the transformer) are currently connected to the two 24 VAC terminals of the Rainbird. If they are both NOT controlled by any switch, can I just pick one of them? I would imagine they both supply 24 VAC, so they should not have any difference - is that correct? Or I’m missing something there?

post by DLane on May 10, 2023

@leilobound - the 120 VAC supply line is probably the lower set with a black, white and bare (copper) wire. Those are the wires that would be connected to the Rachio external enclosure. Everything else from the Rainbird should be abandoned.

post by leilobound on May 10, 2023

Thanks @DLane!
It’s amazing you can tell by just looking at the picture. I have no idea.

post by leilobound on May 14, 2023

Hi @tmcgahey @DLane @Thomas_Lerman

I took out the Rainbird and all the wires are shown in the picture below.

The UPPER NM cable is connect back behind the wall to the input of the Rainbird transformer. The circuit break panel control the LOWER NM cable. I tested the black wire of the lower NM cable with voltage meter. There is no voltage after I turn off the circuit breaker.

But for the black wire on the upper NM cable, I tested the same way and there is NO voltage on the black wire at all.

So I should use the lower NM cable for the Rachio enclosure - correct? Also, should I just cut the wires (black, green, white) that are connecting to the Rainbird transformer and protect them with wire nuts and tapes? And same for the upper NM cable just put wire nuts and tapes?

post by DLane on May 14, 2023

For any wire I abandon in place I cap them with a wire nut and maybe wrap it with electrical tape - belt and suspenders approach. No need to cap or tape the bare copper wire. If you want to use the Rachio outdoor enclosure, then you can attach the lower NM wires to it and plug the Rachio transformer into its outlet, otherwise keep using the switched outlet.