Carrier 19XR frame 5

[chillerguru]

Has anybody expierenced:
Alarm 247 DIFFUSER POSITION FAULT. If so please give me details. i did find a few service bulletins with information. what kind of failure have youve seen. is it more mechanical or electrical and alignment issues. has anbody expierence internal broken parts on the split ring diffuser. also why was the split ring diffuser added on the larger machine, was it just a capacity enhancement. im very familiar with the older 19xl and smaller 19xr machines to date back to the r22 19xl issues. please reply any information thanks.

[OpenDrive]

This is a very common fault with these XR5's. The Actual issue is usually not the actual diffuser motor. It is the potentiometer on the IGV motor. If you look in the Configuration settings, there is a % diffuser opening that corresponds to a % IGV opening. If the IGV motor Pot has a bad spot in it. At certain points these will not correspond and the alarm will be generated. The Split Ring diffuser is pretty reliable if set up right. This was added to allow less surging at lower loads, I believe. These will tend to jam up when aluminum from a damaged impeller gets in the rack teeth on the ring. You can uncouple the diffuser motor and check for relatively free movemnet of the diffuser shaft. It should turn by hand without using tools but with a firm grip. Try going into the guide vane calibration screen and calibrating. Look for "jumpy" numbers on the volts reading while it is self calibrating. If you see jumpy readings. Replace the IGV motor, or the pot on the back of it. There is also a setting in the Configuration<service menu that allows you to set the maximum mA for full travel of the diffuser motor. Make sure this is set so the diffuser motor dont try to drive past the full span of the diffuser. Hope this helps

[rscamaro]

Has anybody expierenced:
Alarm 247 DIFFUSER POSITION FAULT. If so please give me details.

Just had that fault the other day on a start up. Cycled it for the 2nd. time (after checking initially) and it has been ok. I was told that someone found a setscrew loose on a start up so you may want to at least check that.

...Ron