Forum Discussion
jdubya
Aug 15, 2017Explorer
Now rereading some of this info, I noticed Doug's comment about Intellitec, stating that he had never received any negative comments about Intellitec. I agree with that in that the design is fine. The installation in my coach was a little weaker than I would have liked. But the main thing is that it is almost impossible to adjust the thermostats - if you change it, you cannot find the same spot the next time. The ergonomics are nuts - it is impossible to read the markings without a flashlight. The switches cannot be changed easily because of the detents between and then they are difficult to align with the appropriate mark. That wouldn't be so bad except that you have to change them each time the unit is turned off. If you could set it and then turn it off and back on without having to realign the switch on the right place, it would be usable. Another problem is that the AC1 is on the left side and refers to the front A/C, not the rear A/C. This is reverse from what it should be. The air temperature is sensed by two thermistors, one located immediately above the thermostat and the other 5 feet away inside the main cabin. They are too close together. It is like putting the thermostats in your house all at the downstairs cold air return plenum.
However, with all that - it still works quite well.
In addition, the thermostat is no longer available and must be replaced if a new thermostat is required.
So after looking at all of this again, it does not appear that the new thermostat will work well with Intellitec. The change over will require multiple devices to switch them if modifications to allow inputs to the power, compressor and fan functions is not easily accomplished.
what I mean is:
1) The Intellitec has to know when the power is turned on at the Atwood thermostat. By taking power from the same point as the Intellitec thermostat, input to the Atwood thermostat should be ok, but the Intellitec won't know about it. When the Intellitec thermostat is switched to a fan or fan/compressor combination, the Intellitec controller can determine what to do, but somehow the Atwood thermostat needs to do the same thing when it is switched on.
2) The Intellitec can assume power-on at the Atwood thermostat when none of the fan positions are powered on. That would initiate the Intellitec controller's timeout to the compressor. But the fan input needed is that any of the fan positions are on, not which one, and then the fan output from the Intellitec needs to be able to remove fan power somehow.
Shedding the power to the fan by Intellitec could be done by shedding power to the Atwood thermostat. In other words, the power to the Atwood thermostat would be the Intellitec power to run the fans. Intellitec's controller would be sensing that all of the power is being used and would not allow power to the two air conditioners or to either one as indicated by the 'shed' lights.
Then if power became available, the Intellitec would re-power the lines, but someone would have to turn the Atwood thermostat on in order to get things to work - so power to the thermostat as the fan function inhibitor does not work as previously was stated. The Intellitec controller needs something to tell it that the Atwood thermostat has been turned on. Right now, that would require a mod to the thermostat to provide such a pin out.
3) Once the Intellitec controller receives the input concerning power at the Atwood thermostat, it times out 2 or 3 minutes minimum to keep from turning on the compressor too soon and it immediately allows power to the fans. Again the Intellitec has to be able to control the input to the fan, but not necessarily the speed level - Atwood thermostat can do the speed levels. But to do so and allow the Intellitec to shed the fans, the Atwood thermostat would have to receive power for the fans from the Intellitec controller. It would seem logical that the fans selection would be powered from the on/off selection of the Atwood thermostat, so power to the fans could be interrupted by having a jumper (two pins - one out; one in) to allow normal function and also allow Intellitec's controller to intercept the fan function if needed. If it is not already available, that should be a fairly easy mod to the Atwood thermostat.
4) The Atwood thermostat would then select the fan speed and not be required to have the opto isolators to allow fan shedding. But now the power to the compressor has to have similar functionality. The fans have to be allowed to run and the Intellitec controller allowed to shed the compressor. The only way to provide this is to use the Atwood thermostat's fan power on (return pin of the pair for fan control) as the input to the Intellitec controller to operate the compressor shedding on the Intellitec. To allow shedding of the compressor, the Atwood thermostat has to receive power input for the compressor that may be interrupted by the Intellitec controller. The Intellitec controller's compressor line must be the input to the Atwood thermostat to power the compressor output of the Atwood thermostat. This means that the Atwood thermostat would require a modification to add a jumper pair again for fan out to compressor in on the Atwood thermostat.
5) The thermostat inputs on the Intellitec controller would have to be jumpered to the appropriate on level so that the controller is told that A/C function is needed all of the time, while the Atwood thermostat would actually turn the compressor on and off with the power thus provided so that shedding would be possible.
These two mods (actually four mods) would be fairly easy to accomplish if the locations for these functions is available and real estate on the board is available to allow the mods to be made. The mods would entail locating the points, severing the connection, installing a pin on either side and fashioning a jumper so that the unit will run as originally designed. These jumpers may already be available as test points on the board, but doubtful.
The alternative method as previously described is more complex, but this method probably voids the warranty.
However, with all that - it still works quite well.
In addition, the thermostat is no longer available and must be replaced if a new thermostat is required.
So after looking at all of this again, it does not appear that the new thermostat will work well with Intellitec. The change over will require multiple devices to switch them if modifications to allow inputs to the power, compressor and fan functions is not easily accomplished.
what I mean is:
1) The Intellitec has to know when the power is turned on at the Atwood thermostat. By taking power from the same point as the Intellitec thermostat, input to the Atwood thermostat should be ok, but the Intellitec won't know about it. When the Intellitec thermostat is switched to a fan or fan/compressor combination, the Intellitec controller can determine what to do, but somehow the Atwood thermostat needs to do the same thing when it is switched on.
2) The Intellitec can assume power-on at the Atwood thermostat when none of the fan positions are powered on. That would initiate the Intellitec controller's timeout to the compressor. But the fan input needed is that any of the fan positions are on, not which one, and then the fan output from the Intellitec needs to be able to remove fan power somehow.
Shedding the power to the fan by Intellitec could be done by shedding power to the Atwood thermostat. In other words, the power to the Atwood thermostat would be the Intellitec power to run the fans. Intellitec's controller would be sensing that all of the power is being used and would not allow power to the two air conditioners or to either one as indicated by the 'shed' lights.
Then if power became available, the Intellitec would re-power the lines, but someone would have to turn the Atwood thermostat on in order to get things to work - so power to the thermostat as the fan function inhibitor does not work as previously was stated. The Intellitec controller needs something to tell it that the Atwood thermostat has been turned on. Right now, that would require a mod to the thermostat to provide such a pin out.
3) Once the Intellitec controller receives the input concerning power at the Atwood thermostat, it times out 2 or 3 minutes minimum to keep from turning on the compressor too soon and it immediately allows power to the fans. Again the Intellitec has to be able to control the input to the fan, but not necessarily the speed level - Atwood thermostat can do the speed levels. But to do so and allow the Intellitec to shed the fans, the Atwood thermostat would have to receive power for the fans from the Intellitec controller. It would seem logical that the fans selection would be powered from the on/off selection of the Atwood thermostat, so power to the fans could be interrupted by having a jumper (two pins - one out; one in) to allow normal function and also allow Intellitec's controller to intercept the fan function if needed. If it is not already available, that should be a fairly easy mod to the Atwood thermostat.
4) The Atwood thermostat would then select the fan speed and not be required to have the opto isolators to allow fan shedding. But now the power to the compressor has to have similar functionality. The fans have to be allowed to run and the Intellitec controller allowed to shed the compressor. The only way to provide this is to use the Atwood thermostat's fan power on (return pin of the pair for fan control) as the input to the Intellitec controller to operate the compressor shedding on the Intellitec. To allow shedding of the compressor, the Atwood thermostat has to receive power input for the compressor that may be interrupted by the Intellitec controller. The Intellitec controller's compressor line must be the input to the Atwood thermostat to power the compressor output of the Atwood thermostat. This means that the Atwood thermostat would require a modification to add a jumper pair again for fan out to compressor in on the Atwood thermostat.
5) The thermostat inputs on the Intellitec controller would have to be jumpered to the appropriate on level so that the controller is told that A/C function is needed all of the time, while the Atwood thermostat would actually turn the compressor on and off with the power thus provided so that shedding would be possible.
These two mods (actually four mods) would be fairly easy to accomplish if the locations for these functions is available and real estate on the board is available to allow the mods to be made. The mods would entail locating the points, severing the connection, installing a pin on either side and fashioning a jumper so that the unit will run as originally designed. These jumpers may already be available as test points on the board, but doubtful.
The alternative method as previously described is more complex, but this method probably voids the warranty.
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