Carrier Access Thermidistat operating instructions ÐW1 / W2 Outputs, Option 10ÐDual Fuel Equipment

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Option 10ÐDual Fuel Equipment

All dual fuel installations must be equipped with a high pressure switch to turn off compressor under a high indoor coil pressure condition.

The high pressure switch protects compressor and indoor coil from overpressure which would occur if a failure or wiring error resulted in the heat pump and furnace operating at the same time. High Pressure Switch Kit includes required switch and instructions for proper operation. For all dual fuel installations, outdoor temperature sensor must be attached. If not, E3 error message will appear. See "Error Codes."

This option requires prior selection of heat pump (DIP switch 1ÐON), and must be selected in dual fuel installations. It prevents simultaneous operation of both furnace and heat pump, and prevents direct transition from heat pump to furnace operation. When system is dual fuel (heat pump and furnace), set to ON. When system contains fan coil, set to OF. Factory default is OF (off).

TO SELECT:

1.Enter configuration mode if not already there. See Step 4 "To Enter Configuration Mode." Use up and down buttons to make small (now flashing) display indicate 10.

2.Press SET TIME/TEMP button once to flash large display.

3.Use up or down buttons to alternate between OF and ON on large display. Factory default is OF.

4.Press SET TIME/TEMP button again to flash upper small display for selection of another option, or press END to exit configuration mode.

Option 11ÐBalance Point Setting

This option is for dual fuel installations only. It requires prior selection of heat pump (DIP switch 1 -- ON) and dual fuel equipment (Option 10 -- ON). It allows selection of an outdoor temperature of 5oF. through 55oF. (or equivalent values in C.), or OF (off). Heat pump is prevented from operating for outdoor temperatures below selected temperature. If OF (off) is selected, heat pump operation is allowed at all outdoor temperatures. Factory default is OF (off). This setting can only be equal to or below the setting choice made for Option 8. Moving the setting higher may 'push' Option 8 setting upward.

If the outdoor temperature is above the "balance point setting", the heat pump will energize first to try to satisfy the indoor tempera- ture demand. If the heat pump does not make a sufficient improvement within a reasonable time period (i.e. 15 minutes), then the gas furnace will come on to satisfy the indoor temperature demand. If the outdoor temperature is below the "balance point setting" the heat pump will not be allowed to operate (i.e. locked out), and the gas furnace will be used to satisfy the indoor temperature.

There are three separate concepts which are related to selecting the final "balance point setting". Read each of the following carefully to determine the best "balance point setting" in a dual fuel installation:

CAPACITY BALANCE TEMPERATURE:

This is the point where the heat pump cannot provide sufficient capacity to keep up with the indoor temperature demand because of declining outdoor temperature. At or below this point, the furnace is needed to maintain proper indoor temperature.

ECONOMIC BALANCE TEMPERATURE:

Above this point, the heat pump is the most cost efficient to operate, and below this point, the furnace is the most cost efficient

to operate. This can be somewhat complicated to determine and it involves knowing the cost of gas and electricity, as well as the efficiency of the furnace and heat pump. For the most economical operation, the heat pump should operate above this temperature (assuming it has sufficient capacity), and the furnace should operate below this temperature.

COMFORT BALANCE TEMPERATURE:

When the heat pump is operating below this point, the indoor supply air feels uncomfortable (i.e. too cool). This is purely subjective and will depend on the homeowner's idea of comfort. Below this temperature, the gas furnace should operate in order to satisfy the desire of indoor comfort.

TO SELECT:

1.Enter configuration mode if not already there. See Step 4 "To Enter Configuration Mode." Use up and down buttons to make small (now flashing) display indicate 11.

2.Press SET TIME/TEMP button once to flash large display.

3.Use up or down buttons to move between OF, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, or 55 on large display. Factory default is OF.

4.Press SET TIME/TEMP button again to flash upper small display for selection of another option, or press END to exit configuration mode.

Option 12ÐDefrost Heat Select

This option allows installer to select the amount of heat provided by Thermidistat Control during a heat pump defrost cycle. This can be very helpful in maintaining a comfortable leaving air tempera- ture during defrost. The Thermidistat Control senses when defrost is in progress by monitoring voltage placed on the O line by the heat pump while defrosting. It responds by turning on selected combination of W1 and W2 during defrost. Note that this is very different from the operation of an ordinary thermostat, which cannot sense defrost in progress and only turns on its W outputs in response to a temperature demand. Combinations of W1 and W2 are selected via the following:

Table 1ÐW1 / W2 Outputs

SELECTION

DEFINITION

0

Neither W1 or W2 is turned on.

This is factory default.

 

1

Only W1 is turned on.

2

Both W1 and W2 turned on.

3

Only W2 turned on (available

only if 3-stage heat is selected).

 

 

 

The selection procedure is given below. If 0 is selected, operation is like that of an ordinary thermostat, and a wire is required between W2 of outdoor unit and a selected W on indoor unit. When selection 1, 2, or 3 is made, no wire should be connected from outdoor W2 because this connection may override selection made. Obviously the heater must be in 2 sections, and fan coil jumper must be removed between W1 and W2 for there to be a difference between selections 1, 2, and 3. For most heaters, W1 is lower wattage heater, and W2 is higher, although some have equal elements for W1 and W2. Consult fan coil/heater combination for the actual wattage connected to each of W1 and W2.

In dual fuel applications, above selection choices apply and can be used to select low or high heat if furnace is 2 stage. W1 will produce low heat. W1 and W2 together produce high heat. This option provides no value with single-stage furnaces because only 1 value of heat is available.

The selection choices guarantee selected outputs will be on during defrost. If room temperature demand requires additional heat, it

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Contents Installation Considerations Safety ConsiderationsIndex IntroductionÐSet DIP Switches InstallationÐInstall Thermidistat Control ÐThermidistat Control LocationOption 1ÐAnticipator Adjustment ÐSet Thermidistat Control ConfigurationOption 2ÐClean Filter Timer Option 3ÐEnglish/MetricOption 4ÐFan G On With W Option 8ÐAuxiliary Heat Lockout SettingOption 5ÐVariable-Speed ICM Blower Option 6ÐCooling Lockout Below 55FÐW1 / W2 Outputs Option 11ÐBalance Point SettingOption 10ÐDual Fuel Equipment Option 12ÐDefrost Heat SelectOption 14ÐHeat/Cool Dead Band Adjustment Option 13ÐRoom Temperature Offset AdjustOption 15ÐEnable Auto Mode Option 16ÐEnable Super Comfort Heat ModeRedefinition of Buttons Option 17ÐEnable Non-Programmable OperationÐSystem Start-Up and Checkout To Test FANÐFinal Settings ÐEnergy Star Default ScheduleHumidity Control Features ÐEquipment OutputsAdditional Humidify Comments ÐHumidification SelectionsTo Select Dehumidification Between NORMAL, Cool TO, and OFF Superdehumidify With Cool to DehumidifyDehumidify Output and Equipment Connections ÐDehumidification SelectionsVacation Vacation Set PointsOperational Information Thermidistat Control TroubleshootingVacation Dehumidification Evesleep Thermidistat Control Configuration RecordWakeday

Thermidistat specifications

The Carrier Access Thermidistat is an advanced thermostat designed to optimize indoor climate control, providing both comfort and energy efficiency. As part of Carrier's commitment to innovation in heating, ventilation, and air conditioning (HVAC), the Access Thermidistat combines modern technology with user-friendly features.

One of the standout features of the Carrier Access Thermidistat is its Wi-Fi connectivity. This allows users to control their home environment remotely via a smartphone, tablet, or computer. With the Carrier mobile app, users can adjust temperature settings, schedule heating and cooling cycles, and monitor energy usage from anywhere. This convenient feature not only enhances user control but also helps in managing energy consumption more effectively.

The Access Thermidistat is equipped with advanced algorithmic technology, which continuously learns user preferences and adapts accordingly. This smart technology assesses factors such as occupancy patterns and external weather conditions, optimizing the HVAC system’s performance to create a personalized comfort experience. By doing so, it reduces energy waste and lowers utility bills, making it an economical choice for homeowners.

In terms of compatibility, the Carrier Access Thermidistat works seamlessly with a wide range of heating and cooling systems, including central air units, heat pumps, and zone control systems. This versatility makes it an ideal solution for both new installations and retrofitting existing systems, ensuring homeowners can easily transition to a smarter climate control solution.

Another notable characteristic of the Access Thermidistat is its intuitive touchscreen interface. Users can easily navigate the menu to adjust settings, create schedules, and view energy reports. The display also provides real-time feedback on current indoor conditions, including temperature and humidity levels, which helps users make informed decisions about their HVAC usage.

Moreover, the Carrier Access Thermidistat features multiple scheduling options, enabling homeowners to set specific temperature settings for different times of the day or days of the week. This flexibility ensures that energy is conserved when the house is unoccupied while maintaining comfort during peak living hours.

Safety and reliability are also paramount in the design of the Access Thermidistat. It incorporates features such as energy-saving modes and alerts for system malfunctions or maintenance needs, ensuring that users are always informed about their HVAC system's performance.

In summary, the Carrier Access Thermidistat is a cutting-edge solution that combines connectivity, automation, and user-centric design to enhance the overall HVAC experience. By integrating smart technology with practical features, it offers a superior way to manage indoor climates efficiently and conveniently.
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