New project.
Had my furnace inspected. Due to combustion gas leaks the furnace has been replaced. Of course I kept the old parts. Now I have this motor and want to use it. It's the air handler blower. It has 9 pins as you'll see in the photos. I also have the control board so if I have to use it via the control board I can.
Here's several pictures. The blower ran on 120 VAC but I don't think the 120V was what was being controlled. As you can see there are several wires doing what - I don't know. Not yet.





OK, managed to get a clear picture of the C • Rx • Tx • +V terminals.
I've rotated the motor shaft and have found 12 distinct detents so I'm thinking this is probably some sort of inverter motor. The heater was able to modulate the fan speed depending on the need for heat. If the furnace was producing a lot of heat the fan would run at full speed. If it was merely warming the house by one degree the fan would run at a much slower speed.

WHAT I WANT TO DO:
Use this fan and build a wind tunnel for my other project - model rocketry. Being able to find the CG (center of gravity), hang the rocket body in the airflow and determine whether the design is stable or not. None of that probably matters. The BIG question is "How to run this motor". As for the furnace schematic - the HVAC company now has that panel. If they still have it - if it hasn't been taken to the dump - they will shoot a copy of it and send it to me. I would still like some help figuring this thing out.

I haven't removed the back cover of the motor yet. I'm hesitant to do so because I don't know what may pop out - what I might not be able to put back together without some specialized tooling. So before I go any further I thought I'd ask you Guru's.

Thanks for the assistance.

 

Found this image of the cap removed from the motor:
Also found this:
https://www.manualslib.com/manual/2450524/Regal-Genteq-Ecm.html?page=22#manual
But not very helpful to me.

 

Most motors in HVAC systems now are ECM (electronically commutated motor).
They are much more versatile regarding variable speed control than the older methods. often the commutator electronics is on board the motor.

 

Thanks @MaxHeadRoom. You saw the plug body. On the 5 pin connector pin 5 is hot (120VAC) pin 4 is neutral, pin 3 is ground, pins 1 & 2 are jumped for a 120VAC system. If 240 pin 3 is still ground, pins 4 & 5 are 120V each.

It's the 4 pin side I am unsure of. Heck, never mind "unsure". I have NO IDEA what each is for. Perhaps C is for common, Rx & Tx seem to be self explanatory but +V is obviously a positive voltage. Just how much voltage I have no idea.

 

Wasn't the motor replaced, if so can you measure at the new replacement? No?

 

to me that looks like legacy fieldbus interface. the data cable would be daisy chained from one motor to the next and each can be controlled from some central place. most of the time voltage present is 5VDC but it can be 24VDC as seen with DeviceNet. when you have chance measure it. even if it is RS232 and not a bus interface, it may be to connect some sort of programming (parametrizing) or for monitoring...

 

The whole unit was replaced. This motor comes out of a Lenox. The new furnace is a Ruud.