trane vav

[michael26]

i recently had a ucm on a vav go bad due to a damper motor failing. there was a burnt spot on the back of the board and i soldiered the connections and replaced the motor of course. if i use the front end i can manually open and close the damper everything is fine, once in auto the motor continuously hunts. the front summit ver? 1997, will say 0% but it still reads airflow fine and it never closes at all but you can hear the motor hunting. i have a copy of e ware that i have never used. do i need to reprogram this ucm, also will anything on the front end have to be changed if i do so. also where can i buy the correct cable ,is there a trane part #.thanks any help is appreciated.

[Balibe]

Not sure if you can still get the cable for Eware. Eware has been replaced with Rover. Eware is also dos based and has issues running on xp. With the correct access level to Summit, you can do everything you need with Summit. If you shorted something enough to get burnt spots requiring soldering, there may be other issues in the UCM.

Have you calibrated the VAV, then verified the flow reading with a mag? Keep in mind the VAV should never close 100%, when temp is satisfied the vav is trying to maintain the min cfm setpoint. The hunting could also be due to pressure changes from the incoming air source, reading the flow at the inlet will determine if the motor is hunting to maintain the cfm setpoint or doing something erratic. If the system has been installed for years, may also be a good thng to check the flow ring & clean if needed.

[michael26]

you saw that everything can be done from summit? can this be reprogrammed through summit? when this hunts it is continuous it never drops down to the desired cfm, for example if cfm min is 300 and max is 600 it is always from maybe 900+/- to 1100+/- but it reads 0% i have taken the cone off the end and you can see that it is almost 100% open, so at this point i have to believe the cfm reading is correct for what it is flowing. could it need reprogrammed because i unplugged it to repair the board? if i replace the board and set the address with the dip switches will summit program it? i have experience w/ hw care and e vision but none with trane. if the board is replaced does it have to be programmed or is there a function through summit to do this? did the board go to maybe a default program that could be causing the problem, i have seen this with hw lon vav2 controllers before. thanks mb l.u. 189 cols, oh.

[michael26]

calibration is set for every wednesday morning in summit so i allowed a week to see if this changed anything and it didnt. also my computer is from vietnam years so the dos thing is not a problem and i work for tight as--s that will not come off the money for rover.

[mallron]

:eek: :eek: YOU REPAIRED THE BOARD!!! :eek: :eek: I'm impressed. I would've never considered repairing the board. The board wouldn't have lost it's program from being unplugged, but it might have some other sort of problem from the burnout. Summit will not program a replacement board automatically, it will read whatever info is programmed in the board. You can however change the vav's program from the vav editor in Summit. I would just replace the board, BRD 2806. Program and recalibrate from Summit and you should be good to go.


-JB

[michael26]

thank you, i can get in there on thursday we will see what happens . thanks again!

[michael26]

I replaced the ucm, set it up through summit. it works great! thanks for the help.

[duke of earl]

Is it true that you can configure a vav ucm through summit. I've always used e-ware for this. I know you can use hyperterminal to config. ucm's with a Tracer 100 but was not aware it could be done through summit.

[drivewizard]

Ya, pretty sure you can, if I remember right you have to write down all the config info instead of just saving the config file like in Rover and then downloading it to new board.