Today I ran into a problem that I haven't seen before. One particular VAV box wasn't communicating true valid points. It was like the UCM edit screen, and graphic screen were just stuck in one position. I verified the address, and it was correct along with the link #. I can actually turn the VAV off, and the screens never show that it is offline. The cfm, zone temp., zone temp. setpoint, and operating mode stay stuck on one figure. So i noticed the VAV UCM type, size, and VAV type were wrong. So I started to set it up, and then all of the boxes become non editable. So I tried deleting the UCM, and adding it back with what VAV was actually out there. I got it set up, but it would never show communication. So I reset the boards power one time, and all of the values from before came back, the vav type, size, and ucm type all went back to the way it was before. I am assuming that something may be wrong with the board, but I am not sure. Is there anything else I need to look at? This box was added a few years after the intial Summit system was set up. So I am not sure how they tapped into the network. Do you think staring off could cause something like this?
One other issue at this building that I fight from time to time is some of the spaces start overcooling due to no Hot Water in the Coils. All of the vavs in the building use AHU air for reheating. None of the vavs are fan powered. So all of the vavs have heating min. flow setpoints. Well when the boilers are disabled the vavs don't realize it, and step there airflow up to the heating min. This then in turn subcools the space. Is there some sort of CPL program out there for when the boilers lock out to make the VAVs maintain only there cooling mins?