VisionPro 8000 - Power Question

[SonicExplorer]

Hello,

I noticed in the VisionPro 8000 thermostat installation manual there is a 24v common wire that needs to be connected to avoid battery reliance. Where does this wire usually come from? I'm getting a Trane TEE air handler installed and want to make sure the new stat is not battery reliant. Does this 24v common wire come from the air handler or does it require a special transformer, or is it merely a "ground" from which the thermostat draws relative voltage from the other wires?

Just wanted to get a quick layman's explanation so I can make sure the installer hooks it up correctly, or that I at least know in advance what to request so there are no unpleasant surprises/excuses at installation time.

Thanks,

Sonic

[Keith73]

Your installer should be able to do that at your request and if you doubt he did, take out the batteries and see if it still works after placing it back onto the base.

[samtheman]

tell your installer how you would like it done, that air handler has the capability to power your thermostat. The only question will be do you have enough conductors in your thermostat wire to do the job? Why isn't the installer providing the thermostat?

[SonicExplorer]

The thermostat is a slightly different version of the Trane thermostat (803) but with one terminal set for IAQ style control.

I have an 8-conductor wire at the moment. The new system is a single stage heat/cool heatpump with one 5K heat strip. 8 conductors should be enough I would suspect, HOWEVER, there are also one extra pair of terminals in the stat that will be used to trigger the blower motor to slow down for dehumidification. That might break the camel's back in terms of 8 conductors being enough, but if that's the case then no problem with running another 2-conductor wire for that I suppose.

I just wanted to make sure the stat can be hooked up to run on power from the handler so no batteries will be required. Based upon the replies it sounds like that is indeed the case.

Sonic

[meh70087]

Any new install that We do has all new Tstat and control wire. Tstat always powered via system battery backup for prgmble! 8 conductor is plenty and if im not mistaken your having Var spd so you wont have control of blower spd from stat. set up comfort R and let her go!

[SonicExplorer]

It's a non-communicating handler. The stat has an nc terminal that can tell the handler to go on low blower speed for dehume.