JJkizak Posted July 14, 2015 Share Posted July 14, 2015 Remember that when a transformer opens you will still read voltage but you will have no current flow therefore nothing worky. JJK Quote Link to comment Share on other sites More sharing options...
USNRET Posted July 14, 2015 Author Share Posted July 14, 2015 Remember that when a transformer opens you will still read voltage but you will have no current flow therefore nothing worky. JJK you have me there, explain please. Quote Link to comment Share on other sites More sharing options...
minermark Posted July 14, 2015 Share Posted July 14, 2015 After a nights sleep, i realized the obvious, the stat will, after loosing power, and regaining power, revert to the default mode of >nothing< like it's new right out of the box needing programming. Even a short outage, the stat will lose memory. Most Stats have a small battery for memory, does yours have one? Quote Link to comment Share on other sites More sharing options...
USNRET Posted July 14, 2015 Author Share Posted July 14, 2015 Sorry, can't quote on this machine for some reason.Mine are wired to provide constant 24 vac (via Common wire) to keep the display lit. This is how I know that, for whatever reason, once the tstat calls for a cooling cycle (flashing snow flake), relay makes (tying red 24 vac to fan and cool) the display goes dark (loses the 24 vac common , red or both). Yes, mine has 2 AA battery back-up. All good there. BTW, I do not use 'programming' just set to cool, fan auto, 78 degrees, HOLD. 1 Quote Link to comment Share on other sites More sharing options...
minermark Posted July 14, 2015 Share Posted July 14, 2015 Sorry, can't quote on this machine for some reason. Mine are wired to provide constant 24 vac (via Common wire) to keep the display lit. This is how I know that, for whatever reason, once the tstat calls for a cooling cycle (flashing snow flake), relay makes (tying red 24 vac to fan and cool) the display goes dark (loses the 24 vac common , red or both). Yes, mine has 2 AA battery back-up. All good there. BTW, I do not use 'programming' just set to cool, fan auto, 78 degrees, HOLD. Ok i understand better. By programming i mean any button you push is "Programming" in my head. You touch one button on the Stat telling it to do something, it does it, and will continue to do it's thing till power is lost/surge or another button is pushed. It just does what you tell it to. see my logic ? Quote Link to comment Share on other sites More sharing options...
USNRET Posted July 14, 2015 Author Share Posted July 14, 2015 Exactly, when I have the HOLD activated, any button push releases the HOLD. With the lose of the 24vac, the batteries back it up and the hold is not lost.. 1 Quote Link to comment Share on other sites More sharing options...
minermark Posted July 14, 2015 Share Posted July 14, 2015 Exactly, when I have the HOLD activated, any button push releases the HOLD. With the lose of the 24vac, the batteries back it up and the hold is not lost.. Man, im baffeled behond belief, you have got to chime in on the cure asap. Quote Link to comment Share on other sites More sharing options...
JJkizak Posted July 14, 2015 Share Posted July 14, 2015 Remember that when a transformer opens you will still read voltage but you will have no current flow therefore nothing worky. JJK you have me there, explain please. Even though you measure voltage on the secondary of the transformer if the internal secondary winding is open you will measure voltage which is still induced from the primary but there will be no current flow making the circuit dead. This is one of the tests they give you and demonstrate in electronics school. JJK Quote Link to comment Share on other sites More sharing options...
USNRET Posted July 14, 2015 Author Share Posted July 14, 2015 (edited) Remember that when a transformer opens you will still read voltage but you will have no current flow therefore nothing worky. JJK you have me there, explain please. Even though you measure voltage on the secondary of the transformer if the internal secondary winding is open you will measure voltage which is still induced from the primary but there will be no current flow making the circuit dead. This is one of the tests they give you and demonstrate in electronics school. Tech on the way now, perhaps we will have the answer sooner rather than later. JJK I can understand that happening if you tapped the secondary at the break in the winding but at original tap past break I can only see some bogus, very small measurement of AC registered by a DVM; not the full 24VAC at 50' from the xformer. Edited July 14, 2015 by USNRET 1 Quote Link to comment Share on other sites More sharing options...
minermark Posted July 14, 2015 Share Posted July 14, 2015 Remember that when a transformer opens you will still read voltage but you will have no current flow therefore nothing worky. JJK you have me there, explain please. Even though you measure voltage on the secondary of the transformer if the internal secondary winding is open you will measure voltage which is still induced from the primary but there will be no current flow making the circuit dead. This is one of the tests they give you and demonstrate in electronics school. Tech on the way now, perhaps we will have the answer sooner rather than later. JJK I can understand that happening if you tapped the secondary at the break in the winding but at original tap past break I can only see some bogus, very small measurement of AC registered by a DVM; not the full 24VAC at 50' from the xformer. Well ya know those "Transformers" only cost 5bucks, and if it's an original installed when house was built, cheap to replace. Quote Link to comment Share on other sites More sharing options...
USNRET Posted July 14, 2015 Author Share Posted July 14, 2015 and he didn't even kiss me! Replaced the transformer that was 'bad' and suspected that common wire was shorted somewhere in the structure. Disconnected common (only loss is constant display light). I had to leave and come back to work prior to completed troubleshooting but he only charged me $195.00 for the $6.00 transformer plus the $75 service charge of course. I want a BEER! 1 Quote Link to comment Share on other sites More sharing options...
minermark Posted July 14, 2015 Share Posted July 14, 2015 and he didn't even kiss me! Replaced the transformer that was 'bad' and suspected that common wire was shorted somewhere in the structure. Disconnected common (only loss is constant display light). I had to leave and come back to work prior to completed troubleshooting but he only charged me $195.00 for the $6.00 transformer plus the $75 service charge of course. I want a BEER! You deserve something a tad better than a Beer, you have earned a bottle of good scotch Quote Link to comment Share on other sites More sharing options...
JJkizak Posted July 14, 2015 Share Posted July 14, 2015 What are you gonna do with all of those thermostat controls? JJK Quote Link to comment Share on other sites More sharing options...
wstrickland1 Posted July 14, 2015 Share Posted July 14, 2015 How old is the unit? Carrier parts carry a 10 year warranty. Quote Link to comment Share on other sites More sharing options...
USNRET Posted July 14, 2015 Author Share Posted July 14, 2015 What are you gonna do with all of those thermostat controls? JJK Well I am going to sell them to you of course. Perfect condition, no ghosts involved (unless you consider random excursions 10 degrees below set point an issue). Forum discount $50 a piece shipped. Ready to go as I just dug them out of the thrash can. Send me your address and I'll send paypal info. How old is the unit? Carrier parts carry a 10 year warranty. 10 years 6 months Man tells me that I should have un-plugged the 120 before changing tstat. I tell him that I did, the unit was off line. He asks if I un-plugged both sides of the house (two independent units). Eh no, you got me there I only un-plugged the one I was working on. He writes up the receipt that H/O burned out transformed by failing to unplug unit before changing thermostat. Screw it, the kids rooms are cold and I am having livations. My assumption is that there is indeed an intermittent short between Common and Red which caused this. Common was not used prior to new tstat install. I verified that "Common" at air handler was blue as it was at tstat before connecting. The system worked for 24 hours +/- prior to failure. Such is life. NEXT issue............ oh, it's here now. Anyone want to buy a house in the surburbs of Dallas, GA 30157? Quote Link to comment Share on other sites More sharing options...
oldtimer Posted July 14, 2015 Share Posted July 14, 2015 You still have that place? Quote Link to comment Share on other sites More sharing options...
oldtimer Posted July 14, 2015 Share Posted July 14, 2015 Will you tote the note? Quote Link to comment Share on other sites More sharing options...
USNRET Posted July 14, 2015 Author Share Posted July 14, 2015 Will you tote the note? Heck, I do now with a non-paying / late paying renter. Here you go: http://www.zillow.com/homedetails/473-Paces-Lakes-Rdg-Dallas-GA-30157/51196082_zpid/ Quote Link to comment Share on other sites More sharing options...
oldtimer Posted July 14, 2015 Share Posted July 14, 2015 My brother would love to be back in Georgia. He is in Dallas TX now because jobs are just so much more plentiful. They are very good renters and payers, the problem would be my sister in law would probably kill me if I presented the opportunity for another move. Ownership might help with that. I'll think about how to present the possibility. That is a nice place! Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted July 14, 2015 Share Posted July 14, 2015 Man tells me that I should have un-plugged the 120 before changing tstat. I never have. Guess I've been lucky. I've seen them change several here at work without shutting anything off. 1 Quote Link to comment Share on other sites More sharing options...
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