Pellet stove pontentiomter + time delay relay

Thread Starter

sherlock ohms

Joined Dec 24, 2013
I am trying to learn to interpret wiring diagrams and am stumped by a couple of features on this one for my pellet stove.
1. I do not follow the electrical flow throught the contacts of the Auger Timer. A picture of it shows the letters RTB and the words "second delay" in the upper left corner where the two Yellow wires from the pot attach. On the upper right side are the letters RTA and the words "first delay." There is a reistance symbol with an arrow beneath each. The White terminal on the bottom left is Neutral, but I'm unclear as to the Black and the Blue. Then manual shows Black to Blue as Load/Output, and the Black to White as Input.
I know the pot controls the length of time delay the Auger does not turn, but do not understand how it does this. The Auger seems to turn at a uniform speed, a uniform Auger run time, but a variable Auger off time.

2. The Auger Motor has a Blue and Black wire, but seemingly no Neutral. Is the Blue a neutral? If not where is the neutral leg for the Motor?

3. The Vacuum Sensor Switch closes when the Combustion fan is running, cutting power as a safety measure if the fan fails. Wouldn't both Blue wires be voltage "hot" wires, and if so, then the Blue wire entering the Auger Timer would be "hot" as well as the Black, which doesn't make sense and gives me the spinning head I have now.

thanks for any and all comments. scott



Joined Jul 18, 2013
It looks like the Blue wire switches through to the neutral?
If a 120vac motor, then is is generally not that important as to which is the neutral.
Not common to switch the neutral like they do in the drawing.
Last edited:


Joined Nov 7, 2013
At first look it seems blue is the neutral to the auger timer.

Unconventional switching the neutral thru contacts in the timer.

I didn't print it out so I could be mistaken.


Joined Nov 7, 2013
The ones to resistor are part of the electronic timing circuit.

Orange/black is "hot" powering electronics.

Whites are neutral and are switched thru relay contacts to blue. Feeding a neutral to auger when needed.