RHEOX INSTALL GUIDE
On July 9, I installed a Rheox to a SAE300-HE machine which had a L21-20R receptacle. The key consideration is that the receptacle is a third party installed item and our job is to map it out. The Rheox is a polarity dependent unit. That means you can’t mix up the positive and negative lead.
Our job is to understand the pinout which most likely consists of two AC wires, a ground, and two DC wires. With a multimeter, we are going to find the two AC wires that we use for grinding in order to exclude them from our search.
We will probe the pins of the receptacle. If your multimeter cannot reach inside the receptacle, use an existing plug with the back off and put your probes on the screws. Important you understand what I’ve written below is to be done exactly to achieve accuracy and minimize the steps.
Steps Are:
Machine running, remote switch set to local, put your multimeter to 200 AC, and find two spots that provide you something like 80VAC in low idle and 120VAC in high idle. In my install, it was W and X.
Now that W and X were excluded, I have Z and Y left over (I assumed during my install that the center pin was ground)
Machine running, remote switch set to remote, put your multimeter to 200 in the DC mode. I put my leads on Z and Y and swapped them until my reading was positive and not negative. Once positive, I wrote down the letter that the red lead was attached to. In this case, it was Z positive and Y negative.
Now that we have Z positive and Y negative, with your leads on those two, reach over, machine running, and set your remote switch to local. Done correctly, your value will go away.
5. Done right was a confirmation step that Z is positive and Y is negative. The Rheox has two 14 gauge wires, one red and one black. The red is the positive lead. The black is the negative lead. They are polarity dependent and cannot be reversed.
Next step is the flyback diode install: https://www.dkwremotes.com/blog/flybacksimple