On Sun, 17 Jan 2010 12:54:05 -0500, Terrence R. Redding Ph.D. wrote:
>I need to trouble shoot my rotor control system. I have a G-800SA. Does
>someone know the output voltages of the four wires coming from the
>controller and can someone tell me how to test the rotor from the ground so
>I don't have to remove the rotor to do it.
There are five active conductors in the cable between the rotor and the
controller. (The drawing shows pin 6 being wired between the controller and
the rotor, but I believe that is for compatibility between this rotor and
other models. There is no connection to pin 6 inside the rotor.
At the ROTOR, pins 1, 2, and 3 connect to a pot that senses rotor position.
Pin 1 is the top of the pot, pin 2 is the slider, pin 3 is the bottom of the
pot AND is bonded to the chassis of the rotor. Pins 4 and 5 go to the motor
through limit switches. If the rotor is not at its limit, you should read
the resistance of the motor through the switches. The pin numbers at the
rotor carry through to pin numbers at the controller.
At the rotor, the motor of my G-1000DXA reads 8.75 ohms (that is, between
pins 4 and 5). The pot is 500 ohms. If you measure at the controller end of
the cable, you will see the cable resistance in series. If you translate
conductor size requirements to resistance, you should use copper big enough
that the loop resistance of the MOTOR pair (that is, pins 4 and 5) does not
exceed 2.5 ohms. The G-800DXA is wired the same way. So for my rotor, I
should read no more than about 11 ohms between pins 4 and 5, I should read
500 ohms between pins 1 and 3, and some resistance between 2 and 500 ohms
between pin 2 and either pin 1 or pin 3.
If you're measuring with an ohmmeter at the controller, you should read no
connection between the motor pair (pins 4 and 5) and the chassis of the
rotor (pin 3).
Now, your rotor is the SA model, but mfrs tend to be fairly consistent from
model to another, so I'd bet that yours is not very different from mine.
If your motor reads open, it could be that it's at a limit, in which case
one of the limit switches would be in its open position.
The manual for the controller says 11-24VDC to run the motor, and the
polarity will change to reverse direction of rotation. BTW -- the manual is
online, although not easy to find. These resistance values are NOT in the
manual -- I had to measure them so that I would have troubleshooting info.
I don't know if the controller will put out voltage with no rotor connected.
There may be logic to prevent it. Or maybe it depends entirely on the limit
switches.
You should also be able to put 12VDC on pins 4 and 5 of the rotor cable and
make it turn (if a limit switch is not opened). (A limit switch is a small
switch activated by the position of the rotor at one end of its travel.) The
DC supply should be capable of at least 1A.
73,
Jim K9YC
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