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249 VAN Launch Kit 249 VAN Consumer Brochure Smart Thermostat Sell Sheet 249 VAN Launch Kit

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This installation was on a 4-story home, and the tech had not yet gone to the basement to troubleshoot the “infinity” water source heat pump, as he was told he by the homeowner. He was in the attic at the infinity furnace above the 4th floor. He was getting his dcv in the proper range on his A and B green plug on the air handler, 3 to 4 vdc. His indoor board ohm reading was in range, 28k to 32 k. The tech ohmed out the A and B thermostat wires on the water source heat pump from the upstairs. His ohm reading was not in range of a normal infinity board. His reading was around 64.4k. The tech then made the long walk to the basement where the “geothermal heat pump” was located. Bingo.

Now get out there and organize some zone wiring!

Zone equipment would be identified as indoor unit- blue black/ outdoor unit-blue green:

Two wire bundles with colored insulated wires fanned out from wrapped cable ends on a white background

Customer dashboard with summary cards, table, and blue action buttons on a dark left navigation sidebar

I have cropped some screens, and modified the serial numbers to keep certain dealer and customer’s information private. Setting the customers up on the portal is an easy process and could reap many benefits. Carrier and Bryant are going to begin utilizing this portal more with new upcoming equipment.

Get out there and get connected to the portal!

Dark settings dialog with notification checkboxes, two green-checked options, and a blue Save System button

Marketing dashboard titled “Connected Portal” with two portal tiles, blue and red icons, and arrow links

Web dashboard showing “Outdoor Control Details” with collapsible sections and a purple-highlighted right sidebar arrows

*Wiring diagrams highlighted with colors chosen for high contrast- not for wire color designation*

Low voltage starts in the red box at the transformer, 24vac goes to the Indoor Fan Board (IFB), through a fuse and on to the thermostat. Depending on what the thermostat calls for, 24vac will be sent down a different wire(s) to turn on/off the multiple devices in the system. The other low voltage wire (C) has an unbroken path to EVERY component in the unit. I have highlighted the pathway in blue and circled each component in purple. This wire/path is something each device has in “common”—it is the common wire. In layman’s terms, the common wire is the return pathway for voltage to come back to the transformer since it left out on the 24vac side.

The Common wire/terminal is always the one thing that is relatable or in common with the surrounding wires/terminals. Relays, motors, control boards, and even transformers all have some type of common wire/terminal. Common for a relay isn’t the same as common on a motor, but within each given device they carry the same meaning. Now go back and reread the second paragraph above—it will have a deeper meaning now.

Challenge: Check out the high voltage side of the Transformer. It has a COM terminal…. it’s not low voltage common. What is it?

That’s all.

One of the most popular combinations right now is the FV4 air handler with a 2 stage outdoor unit with a/c driven dehumidification. This combination is an awesome thing when it is adequately setup. When this system is installed and it is not setup or wired correctly it will not pull moisture from the home but instead cause the home to have higher humidity. I have made a guide to walk you through setup up and wiring this system to allow the homeowner to reap all of the benefits their system is capable of. This setup slows the blower down while running in the cool mode which causes the evaporator coil to be extremely cold. With the blower running slower and the coil being colder it allows more moisture to be removed from the air. If a home has high humidity due to infiltration, this setup will not correct their problem.

Sequence of operation for Dehum:

When dehum alone is needed (and overcool is setup) the unit will deenergize the ACC+ terminal and run the unit in cool. If overcool has been maxed out or has been set to zero then the thermostat will deenergize the ACC+ terminal but not run. The thermostat will wait for a cooling demand and deliver a reduced amount of airflow.