YT ACC board

[Randy S.]

I have a one line display VFD conversion from 2003 with the ACC board acting up. Does anybody have any troubleshooting info?

The green LED lights on power up, but then goes out when the unit fires up.
No Red at all. Any ideas?

[klove]

What's the chiller doing that points to the ACC problem?

[Randy S.]

It seems like it runs too fast with the vanes closed, and it it not sending run time to the ISN UDC that runs the system. The other data points seem to be coming over, though. The green LED is not lit.

Haven't been to my work data base of service info yet, but I don't think I have anything on the ACC board. Possibly something external pulling voltage down, but the display seems OK.

Any info or suggestions would be greatly appreciated.

[klove]

Sounds like you're not within the temp window around setpoint to allow stable operation. You may want to look at the total surge count and clear the map if it's high, or possibly the vane pot is out of calibration or defective (shut down and run from closed to open and check readout for 0% to 100%, recal if out), and check the ACC to microprocessor diagnostics for number of errors. The ELWT sensor could be an issue, also. To my knowledge, there's no real t'shooting info on the ACC board. Like most things York, just a lot of Kentucky windage.

[Randy S.]

I know the clearing procedure for the opti-view, but not the one line display.
I'm guessing the number is the same, and then you still have to push the button within so many seconds.

How do I get to the point where I enter the secret number?

[Randy S.]

I found the information I needed in the manual for the VSD. Cleared the surge map in the BRAM, and calibrated the vane actuator. All appears well.

The one line display panels with a VSD use a different ACC card than the optiview models, and the two LEDs on that board function a bit differently than the optiview ACC cards.

[york56]

Randy I found these not sure what version software you have but you may wish to look at the microboard eprom just a thought.

[Randy S.]

Thanks for the info.