[cnczoner]

Hi all,

I'm trying to figure out what type of motor and associated controller I have (in a conveyor reflow oven), and hoping someone here can help...

The motor has 3 wires out the side near the head -- yellow, white and black, and at the back there's an encoder with 2 wires (both red/green). These go to a small controller board with the following wires:
- 4-pin connector with 2 wires for 240Vac power in (via an SSR), the black wire on the motor and white wire on the motor (via an e-stop switch).

- 5-pin connector with 2 wires to the encoder, and 3 wires to the main processor board.

- 2-pin connector with both wires going to the main processor board. One of these I've traced to one of the encoder wires, and the other to the other encoder wire after a resistor, diode, etc. So it looks like it's sending a modified or cleaned-up encoder signal to the main processor board.

There is also a chassis-mounted 5uf, 250VAC capacitor connected across the motor's yellow and white wires. This capacitor is why I suspect it's an A/C motor.

The motor moves in one direction only and at variable speed. It's made by Oriental Motor Japan, but it's not easily accessible so I have not yet been able to get a model #. However, I'm hoping the control signals mean something to someone.

But I can't figure out why 3 wires go to the processor board. Is there some standard to the signals that would be used for these types of motors? perhaps one is ground or positive voltage? Those wire colors are white/black, white/grey, white/orange.

My intention is to replace the processor board with my own processor, so I need to figure out the control signals to move the motor and read the speed.

Thanks,
-Neil.

[Al_The_Man]

A photo would really help.
I suspect this is a AC stepper motor, although they usually run direct off of AC at a fixed (synchronous) rpm?
Oriental motors specialize in DC and AC steppers and synchronous motors.
What the 'encoder' is, is a bit of a mystery, again a pic or model No. would help.
Al.

[cnczoner]

I'll get a pic.

In the meanwhile, I was able to get enough access to determine that the gearhead on the motor is Oriental Motor 4GK180KA. I could not find it on Oriental's website, but did find it on Ebay here. Seems to be a 180:1 ratio. May be helpful if only certain types of Oriental's motors fit those gearheads.

The encoder is what made me think servo, plus only 2 of the motor's 3 wires go to the control board (the third goes to the capacitor).

[cnczoner]

Pic of the motor.

Pic of the controller board.

Pic of the wires/connections and capacitor.

[cnczoner]

So the motor pretty much looks like this. And it seems the capacitor (similar markings too) is one of these.

But the more important question is about the controller -- and more specifically what types of signals I'd need to control this.

[Al_The_Man]

Its a 1ph induction motor, the shaft is usually splined to fit into a mating gearbox shaft.
Oriental also have a Tach on the back of these when they are used with the speed controller.
I think you will have a problem looking for a different controller for this motor.
Scrap that I looked at the wrong page.
It is a low speed split phase synchronous motor.
Al.

[cnczoner]

So my next obvious question is "how?", as in how did you come to that conclusion?

[Al_The_Man]

I have the "Book".
Al.

[cnczoner]

Does that mysterious book explain how I can control this thing? I have 2 options here now... (1) Figure out the control signals to the proprietary board, or (2) get a controller that works with that motor. The first is preferred (time and that this controller is already mounted and mated to the motor etc), and no additional cost. The second is almost guaranteed to work and easier.

I'm going to see if I can reverse-engineer the board to determine where the input control signals go and then see if I can figure out how to control it.

Thanks,
-Neil.

[Al_The_Man]

The information is a bit vague, just that they are 2phase low rpm synchronous motors and just show a diagram running off of AC direct, they show their motor controllers on separate pages but, do not show which particular model hooks to this one.
They also do not show an open frame one like you have, which makes me suspect that this a 3rd party unit maybe?
Al.

[cnczoner]

The motor control board is definitely not Oriental -- it's got "APS" on the bottom, which is the manufacturer of the reflow oven.

[cnczoner]

At this point also, I've done enough circuit tracing to determine that the input to the motor controller is analog, and that's one of the three white (striped) wires, and going into an op-amp. The other two white striped wires are coming from potentiometers that either provide some reference voltage levels, or measure the reference voltage levels. I may have to reverse-engineer part of the main control board to figure it out for sure.

[Al_The_Man]

If it has a tach or other feedback, that is odd as usually a synchronous motor does not need it as the rpm runs automatically dependant on the frequency of the supply.
Al.