GAEYAELE 4 Channel 1 SPDT DIN Rail Mount 12V 24V DC/AC Interface Relay Module (FY-T734-24VACDC)

This product is almost certainly a must if you want to install a Nest Thermostat in your RV. Small enough to fit in the wall once you remove it from the green bracket. Use with a 24vac transformer connected to the Nest, outputting 24vac to the relay then using your existing 12vdc to output as signal to your AC unit.

I ordered this thinking it works with either 12V or 24V, automatically sensing the input voltage. I missed the selector box on the product web page where you have to specify EITHER a 12V or 24V module. There are actually two different products being sold through this same listing. The 24V model was pre-selected, and when I received it, without any accompanying documentation, I didn’t realize that. My application uses 12V, and while the unit would light up the LEDs on 12V input, the relays wouldn’t energize.Eventually I figured out that there were two different products and I ordered the wrong one. Because the product description said both 12V and 24V, I think they could have been more clear. No labels on the product itself say it’s 24V-only. Also, shipping the product with minimal documentation would have clued me in before I wasted several hours in fruitless testing. I deducted one star for poor pre- and post-sale communications.I tested the module with 24VDC and it appears to work correctly. I will keep the 24V model in my inventory, though, because it looks like a high-quality unit and someday I may have an application suited to it. Seller, please either split this Amazon product page into two different product listings, or clarify the description to say 12V ***OR*** 24V.

It worked fine with having all NO channels turn on the same switch, the other channels did not back haul the electricity to the source. However, when using the NC channel to turn on a different switch, that back flowed and turned on other relays just like the trigger. That meant I needed double the relays.

Unlike so many Chinese sourced components on Amazon, this one gives be confidence that it will not only work, but be safe in operation. No doco - as usual, but well labeled. Happy with purchase, meets my needs.

Used this product in a 12vdc 5th wheel trailer when converting the analog thermostat to a smart 24vac Nest thermostat. Used a 120v to 24vac xfmr spliced from the main AC feed as supply. Worked great. Custom wiring diagrams were found online from others completing similar tasks.Would be nice to have a small box or cover for it as i needed to mount this on the wall exposed. Otherwise you can install inside the wall somehow.