2004 Trane system
You system sounds almost identical to mine, installed in 2004: Trane XL19i, variable speed air handler, six zones, one difference is I have twin heat strips at 20 Kilowatts and the eletrostatic filter. My installer used the Honeywell zone board. Which are you using? And the small compressor on my unit failed after 4 years of service and I have had to replace all of the zone damper motors at least once, and in several instances twice. The heat strips were replace after four years and again just a few weeks ago due to the failure of the over-temp fusible links.
Originally Posted by jjnet
My system has always be very expensive to run in the heating mode and just this week I installed a multichannel power monitor (www.brultech.com) to see if I could figure out what was going on. Much to my horror I found that the system has been doing much of it's heating using the heat strips (both of them), and the small compressor was being cycled on and off every couple of minutes for hours on end. I suspect the system has not been set up properly. As an electrical engineer I very comfortable with instrumentation but I don't know beans about "real HVAC".
I'd be very interested to hear your experiences and any suggestions on how to find someone that can diagnose my problems.
I must confess to have lost all confidence in the company I've been dealing with. thanks, -john-
I started a new thread.
im betting you are not flowing enough air , why are they replacing the heat strip when they could just replace the fuse links .you need to call a trane comfort specialist
Agreed to both that posted. You need a Trane dealer that has expersinse in this set up as it sounds to be not wired right at all. The XL19 is great heat pump system when wire and set up right.
Originally Posted by catmanacman
I agree with you (both). I've stayed with this installer too long. The system has a year and a half to go under the 10 year extended warranty from Trane (only covers the Trane parts) so Trane has been eating a major part of the bills up to now. That may be why the installer went with the complete replace rather than than just replacing the fusible over-temp sensors.
Originally Posted by duckman06
My question to you is how to find and qualify some one else. I suppose I've taken sort of a "better the devil you know than the devil you don't know" attitude up to now, but I don't have bags of money to throw at this and I really don't want to go through multiple service calls to find a 'good one'. Should I call the Trane FSR and ask them who to go to?
Thanks for any thoughts, -john-
Well, in utter desperation I documented the wiring of my system, and you were right it was miss-wired. Once I took the wiring diagram into my dealer and showed them, they sent out their best guy, now the Operations Mgr... the following problems were found in the following order:
Originally Posted by duckman06
1: First, of course, was the replacing of the 20 Kwatts of heat strips because the fusible links had blown. That's what started this round of repairs.
2: The Honeywell Zone controller was set up for timer based staging. The timer was set to 5 minutes, so Stage 1 for five minutes, stage 2 for five minutes, then Stage three would fire up both of the heat strips. (no wonder my electric bill were so high.) A great deal of the time the system was using heat strips instead of letting the heat pumps do the work. The stage timing was change to 30 minutes and the use of heat strips dropped dramatically.
3: The ODTs which monitor outside airtemps and decided if it too cold to just use the heat pumps had been bypassed during a previous service call, so, regardless of outside temps, stage three always went to heat strips. There are two ODTs on this system, one for each heat strip. The system was rewired to use the ODTs and the ODTs were set to 30degrees and 35degrees along with a discussion about possibly lowering them further. Now, most night we don't go to heat strips.
4: Once the above was corrected it was noticed that once or twice a day, the air handled would ramp down in a orderly fashion leaving one of heat pumps running which would then go into over-temp lockout for and hour. Replacing the air handler's control board seems to have cured that.
5: While the Operations Mgr was here, one of the six zones dampers stuck closed during Stage 3 heating leaving the zone calling for heat, the air handler fan going flat out, and nowhere for the heat to go. I explained that in the past 9 years zone damper motors had been replaced eight times (on a six zone system). A discussion followed about discharge plenum air pressures and whether that could keep the zone damper closed. Our air handler has a bypass loop with an active (motor driven) damper controlled by a plenum barometric pressure sensor. (which by the way has died once, a few years ago). This is an unresolved problem.
6: It was noticed that there are 'rogue' currents flowing on the copper gnd wires from the air handler and heat pump. Current can be measured flowing on the line set (try put your clamp-on amp meter around a line set some time.) we measure an amp and a half that would appear when a specific heat strip came on and then go away when that heat strip shut off. One of their techs said that he sees this all the time. The Ops Mgr. said that it shouldn't be and it needs to be looked into. This problem is unresolved . I suggested getting a Trane FSR out... They're thinking about it.
7: There is one final problem, or "maybe problem", remaining. It appears that when one specific heat strip comes on, if the stage 2 (large) compressor is running the system will immediately drop back to the small compressor. When the heat strip turns off, the compressors swap instantly back to the large compressor. This can happen several times in 5 minutes. I say, "maybe problem" because what we are actually seeing is the electrical energy to the outdoor unit drop from stage 2 values (large compressor) to stage 1 values (small compressor) and back again. So the problem may be that these rogue ground currents are fooling the energy monitor.
So, its been a huge learning 'opportunity'. If you are interesting in seeing the tool we've been using to understand the behavior of our system you can use your browser to go to my personal web site at www.loram.org. Click on the picture of the graph at the bottom of the home page and you'll go to my energy monitor. My Internet up load speeds can be pretty dismal at times so may may take a few minutes to upload the energy monitor page the first time you view it. Remember that I'm on the west coast (-8GMT), so if you are not, you'll need to remember to adjust the time period you want to view. For example, if you are on the east coast, when you bring up the energy monitor page it will try to display your current time. Let's say Noon. But, Noon hasn't happened here on the west coast, so no data will be displayed. There are five WebPages (see the tabs at the top) to view and you can control which of the seven channels, or combination of channels are being displayed and during what period of time. The monitor has been on the system for about two weeks, so that's all the data that's available. Finally, two things:
1) you'll notice odd repetitive spiking on several channels. The spikes are about 20% of signal amplitude. Its a problem I'm having at the moment with the monitor. Just ignore it.
2) Not everything you see will make sense. Once or twice a day I've shut the system or one of the channels down for anywhere from a few minutes to a few hours, to trouble shoot the spiking problem. However, I think once you spend a little time with it, you'll be able to detect my tinkering.... -john-