How to Wire the nJoin Power Module to an OJ Control

Hello and welcome to today's video. My name is Scott, and I am from WarmlyYours. Today, we are going to discuss how to hook up a system that requires more than 15 amps. If you take a look at these two controls, you can see one is a thermostat and the other is a power module. The thermostat can switch up to 15 amps, which is sufficient for most spaces. For example, when you're working on a master bathroom, you can typically manage it with one control. However, if you're renovating a basement that includes a bar and part of a living space, the total load may exceed 15 amps, potentially reaching 20, 25, or even 28 amps. In such cases, the thermostat will switch the first 15 amps, while the power module will handle the additional load, allowing you to heat larger areas in your home.

Let’s take a closer look at the back of the thermostat to understand the necessary connections. The back of the thermostat is where you will make your high voltage connections, which can be either 120 volts or 240 volts. It’s important to note the difference in coverage area between these two voltages. With 120 volts available, the thermostat can control heating for up to approximately 120 square feet. If you need to heat more than that, switching to 240 volts is advisable, as it allows you to control up to 240 square feet with a single thermostat. For areas larger than 240 square feet, such as 300 or 400 square feet, you will need both a thermostat and a power module.

Now, let’s examine the cover on the back of the thermostat. This cover is crucial as it protects the connections from debris while you are working in a confined space. It is essential to keep this cover and not discard it. In our mock-up, we are demonstrating the connections on a tabletop for clarity, though you would typically perform this installation within a wall box. The black wire you see is the one coming up from the floor, while the yellow and black wires represent the wiring from your circuit breaker. If this were a 120-volt system, the white wire would serve as the neutral, and the black wire would be the line. Importantly, when connecting the wire from the floor, you do not need to worry about polarity, as there is none in the mat. However, the wire from the circuit breaker does require attention to polarity. In a 240-volt setup, you would have two hot wires, while in a 120-volt setup, you would have a line and a neutral.

Next, let’s discuss the color coding and the connections that are not made on the screws. The wire coming up from the floor is a black wire with a yellow and black inside, along with a braided ground. In a 240-volt system, you would typically see red and black wires with a ground. A common question is where to connect the ground to the thermostat. The answer is that you do not connect the ground wire to the thermostat; instead, you connect the ground from the floor to the ground coming from the circuit breaker using a wire nut. This connection is separate from the thermostat.

Now that we have covered the connections at the back of the thermostat and the power module, it’s important to note that these two components connect in the same manner for high voltage wiring. If you are undertaking a large installation, ensure that the thermostat is on its own dedicated line, as is the power module. They should not share a circuit breaker, and it is crucial to use a non-GFCI circuit breaker since GFCI protection is already built into both the thermostat and the power module. If you look closely, you will notice that the bases of both components are identical, which is why they wire the same way.

Let’s now address the blue and white connections that need to be made. As mentioned, both the thermostat and the power module should be on their own circuit breakers. The power module knows when to turn on because it receives a signal from the thermostat through the blue and white low voltage communication wires. To simplify our discussion, I have disconnected the high voltage connection from the back of the thermostat to focus on the low voltage connections. The connections at the back are made with a standard Phillips screwdriver, while the low voltage connections on the front of the thermostat require a smaller thermostat screw.

Now, let’s examine the low voltage connections. The power module has one low voltage connection, while the thermostat has two. One of these connections is for the thermostat wire, which is included in the same box as the thermostat. It’s crucial not to forget to take the thermostat sensor out of the box and give it to the Tile Pro during the tile installation, as it needs to be installed simultaneously with the tile. This sensor can be connected to the thermostat later.

When connecting the thermostat sensor, you will find two terminals labeled C and D. It does not matter which wire goes into which terminal, as there is no polarity in that wire. Now, regarding the power module, it does not receive a thermostat input. The low voltage connection between the thermostat and the power module is made through terminals A and B. It is essential to connect these correctly, as reversing the polarity will cause the power module to turn off when the thermostat calls for heat. You will quickly notice if this connection is incorrect because the behavior of the system will be reversed.

In summary, ensure that wire A connects to terminal C on the power module, and wire B connects to terminal D. It is critical to respect the polarity of the blue and white wires for the low voltage connections. Additionally, it is vital that the thermostat sensor wire is not run in the same conduit as the high voltage wires from the circuit breaker or to the floor, as this could disrupt the low voltage signal and may violate local electrical codes. By following these guidelines, you should achieve a problem-free installation. Thank you for watching our video on how to install a power module and thermostat combination for jobs requiring more than 15 amps.