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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 stripped wire bundles with colored leads, one on left and one on right, against a white background.

Cricket Club admin dashboard on Customers page with sidebar menu, stats cards, and customer table.

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-themed “Edit System” settings dialog with notification checkboxes and a blue “Save System” button

Dashboard page titled “Connected Portal” with two light-blue portal tiles and app icons.

Dashboard page showing Outdoor Control Details with accordion sections and a purple-highlighted side menu.

*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.

When you are installing a thermostat on MOST residential and commercial heat pumps, typically the orange wire goes to the reversing valve. However, when you are installing a lite commercial Carrier system there is no need to consider the reversing valve. So, what are we supposed to do with the orange (reversing valve) wire? You will not use it because the system controls the reversing valve on its own.

The defrost control board that Carrier utilizes on their lite commercial products has logic built into the board to take care of the reversing valve(s), you simply tell the unit if there is a need for heat or a need for cool. When these systems receive a call for Y1 or Y1 & Y2 then the defrost board will energize the revering valve(s) as needed. When the systems are given a W1 call for Heat then the unit will crank up in high stage. The unit only has one refrigeration heating stage even if it is a “2 stage” unit. The “W2” terminals on split units are actually not inputs but rather outputs to engage the electric heat strips when the system goes into defrost; on the package units the “W2” is an input and it engages the electric strip heat if equipped.