Jan 26, 2005 · VVT = variable volume and temperature this unit will maintain the static pressure in the ductwork either with a variable frequency drive or bypass damper. The VVT system doesn't maintain a 55 degree discharge it can be in either heat mode or cool mode which ever it needs to maintain the temperature in the space.

Nov 19, 2014 · These VVT design flaws are not just a Carrier issue, the entire VVT Sequence and design concept is a failure of correct mechanical engineering multi zone engineering; The VVT sequence design was originally conceived to be the lowest "first cost" on HVAC multi zone construction projects

Jan 27, 2025 · I am working on a older Carrier VVT system (generation III). I am having some issues with with some of the supply air temperature sensors on the zones and the outside air temperature sensor on the monitor stat. I was looking through all of my old documentation for a temperature to resistance chart and I can't seem to find one.

Jan 17, 2006 · VVT (or pressure dependant VAV) are not systems that are easy to control. You're usually dealing with small, staged, fast acting RTU's and sloppy boxes. If you tighten the operating parameters, the system will be a source of frustration but if you back off and let things ride a bit, they'll do the job they were supposed to.

May 29, 2024 · Handle the CCN VVT Linkage as if was installed on a third-party RTU like a Trane RTU. The CCN VVT Zone Controllers are designed to work without CCN Linkage to a CCN RTU with third-party RTU's ..... Add a PAT sensor to the master vvt zone of each system. Less than $20.00 and an hour labor.

Oct 13, 2008 · Carrier used to have an option with their older Gen 2 VVT. You could configure them as a Fan Powered Mixing Box series or parallel. I believe the sequence would be the VVT zone controller will energize the fan relay as 1st stage heat when the heating demand rises 1.5 Deg above the occupied heating setpoint.

May 19, 2010 · Had a few places that the VVT had died , customer did not want DDC or COMPUTER interface , wanted a system that worked and was reasonably priced. I put in JACKSON SYSTEMS comfory system. All the exsisting wiring was reused , bit cleaned up and some repaired from being WORKED on over the years but start up was without any glitches.

Sep 3, 2009 · I started doing vvt in the parker days and like pretty much any controls if installed per design, programmed and supported it functions fine for what it is. A failure in any of those areas and you are left with an unsatisfactory experience and frustration. Doodah is correct but heres the reason.

Oct 13, 2014 · Also on a side note I was looking at the control programs loaded into each of the controllers. Most of them are vvt_zn_iv6-3_06_20131017. Which two of these controllers are having issues. I have one controller that is a vvt_zone-2_20100408. Most of the other types of controllers on site have 2010 programs in them. What is the difference?

Apr 19, 2010 · a bypass is just a component of a vvt system, to dump air into the return instead of a vfd. that is in a nutshell!!!!! VAV stands for Variable Air Volume. VAV boxes provide constant or variable air depending on the temperature demands of the space. As the temperature rises the VAV damper opens to send a designed amount of airflow to the room.