Functional Devices RIB2401B Power Relay, 20 Amp SPDT, 24 Vac/dc/120 Vac Coil, NEMA 1 Housing

This was the missing piece for my home solar setup. I have an EG4 3000EHV-48 inverter connected to two eco-worthy 48v rack-mount batteries (purchased from Amazon.com) and some solar panels. The issue was that the inverter does not have an internal Neutral to Ground bonding relay. In simple English, when I tried running my devices on battery, the electrical supply was unstable, the LED lights started flickering, etc. After months of research I was able to determine that the missing N-G bonding relay was the issue and I after more research the Functional Devices RIB2401B relay kept coming up as the relay to get to peform the simple task of monitoring my AC power (power from the electrical grid) on my main panel and then if there is a power outage, it would simply connect the Neutral and Ground wires in my load panel (devices to be powered by battery if I lose power). This worked perfectly, and I am finally able to enjoy my solar investment.

Well OK, it's not easy to get excited about a relay, but this one has worked perfectly for my application. I'm using it to switch speeds when controlling my 2-speed QuietCool ES-3100 whole house fan via my Alexa+SmartThings setup, in conjunction with two on/off Z-Wave switches (one switch controls power to the fan, the other selects Hi/Lo by using this relay). I know the 20 amp rating on this relay is overkill for the 670W fan motor, but I wanted to be prepared in case I want to up-size the fan in the future. I mounted this relay right onto the junction box that's part of the fan; a perfect fit. A lock nut is included with the relay for attaching through 1/2" openings on junction boxes. Very good quality product, highly recommended, with the connection diagram clearly marked on the unit itself.

Worked perfect for replacing my old-school manual mercury switch thermostat on my standalone propane gas glass fireplace/heater. I used a 24V thermostat adaptor to power a new Honeywell smart WiFi thermostat and then I used this power relay, connected to the new thermostat, to then switch the remote thermostat wires from the the fireplace that had been connected to the old thermostat.

Used it to help control my 120vac evaporator cooler with a ecobee 24v smart thermostat . Good quality and isn’t very load when switching. Not a bad price at all either. Can be used in several different ways .

Product as described, good quality, easy to install.

I've used a lot of these over the years to handle 20 amp circuit switching. I've never had a failure. They work down to at least 50 below zero with no problem.

Used this Functional Devices RIB2401B relay to have an Ecobee Lite control a kerosene heater in my workshop to prevent freezing. Setup was simple — installed in minutes, and it’s handling 20A with no issues. I set it to maintain 40°F by offsetting the temperature delta and only trigger when it’s 3° below set point. Now I have full remote control, and the heater cycles exactly as intended. If you want to add smart control to a traditional heater or other high-current device, this relay makes it easy, reliable, and safe.

So I am not an electrician, just a DIY guy - so take this with a grain of salt. But I liked this relay because you could attach it directly to the punch out box of a electric junction box. I used this relay in conjunction with a little giant water pump. Little Giant 554542 VCMX-20ULS-C - also purchased on amazon So my dehumidifier in the basement was always filling up and I had to dump manually. Instead I have the pump as the condensate catcher and it automatically kicks in every now and again based on a float switch to pump out the water to my sewer line. I found a nice tube already going in and just added a T. Not bad. But the water pump also has a float shutoff switch if it overflows. But that switch is low voltage. So I have a 24V transformer supplying the power, and this transformer can either fail the circuit open or fail the circuit closed. There is a nice diagram right on the front. I chose to fail open, but that was just my preference. So again, the transformer supplies the power, as long as the emergency float switch is not thrown, power flows to the 24v side of the relay, and 115v power is supplied to the new outlet to power the dehumidifier. BUT - if the pump starts overflowing, the 24v loop is cut, the transformer shuts off power to the 115v side, and the dehumidifier loses electricity and turns off. Pretty slick