38/40MVC, MVQ

MODES OF OPERATION

The units have 5 main operating modes:

1.Fan Only

2.Cooling

3.Heating (heat pumps only)

4.Auto

5.Dehumidification (Dry)

The units have 2 other modes (manual operation) that are operated in unique situations:

1.Auto Forced Mode (Emergency)

2.Test Mode

Fan Mode Only

In this mode, the system circulates the room air without changing the room air temperature.

Cooling Mode

In this mode, the system cools and dries the room air with the fan running continuously, either at a selected fan speed or Auto fan speed. The fan runs even when the compressor cycles off. This feature enhances room comfort and efficiency of the system.

When the unit is operating in cooling, two sub modes can also be selected:

1.Sleep Mode is an energy saving feature that changes the set point automatically.

2.Turbo Mode is a comfort feature on the 9k and 12k units where the set point is reached quickly by having the fan run on high speed regardless of the speed that has been selected.

Compressor and Outdoor Fan Operation

The compressor and outdoor fan motor cycle on and off based on the conditions of the set point and the room temperature as shown below. There is no minimum run time.

 

 

 

 

 

 

 

Compressor and

 

 

 

 

 

 

 

 

 

 

 

outdoor fan on

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Roo

m

temp. down

 

 

Room temp.

 

up

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Compressor off

 

 

 

 

 

 

 

 

 

 

 

 

fan off

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

T = Room Temperature

0 1.8°F

T-Ts

 

Ts = Set Point Temperature

 

 

 

 

 

 

 

A08106

Fig. 24 – Compressor and Outdoor Fan - Cooling Mode

Indoor Fan Operation

When in cooling mode, the fan runs continuously either at the chosen set speed , or in Auto mode, where the speed is determined by the microprocessor based on the difference between the room temperature and the temperature set point as shown below:

 

 

 

 

 

 

 

 

 

 

 

High fan

 

 

 

 

 

 

Med fan

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Room te

m

p. down

 

 

 

 

Room

te

mp. up

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Low fan

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.8 °F

7.2 °F 9.0 °F

T-Ts

T= Room Temperature

 

 

 

 

 

 

 

 

 

Ts = Set Point Temperature

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A08107

Fig. 25 – Auto Fan - Cooling Mode

Sleep Mode

When in cooling mode, additional energy savings can be realized by selecting the Sleep setting. When the Sleep setting is selected, the temperature set point is adjusted automatically as shown below:

Set point

 

1.8°F

 

1.8°F

 

 

1

2

Time (hour)

A08108

Fig. 26 – Sleep Mode

The unit will shut off 7 hours after the Sleep Mode is selected.

Turbo Mode

When in cooling mode, selecting Turbo will allow the indoor unit to satisfy the temperature set point as quickly as possible. In Turbo Mode, the indoor fan will shift to high speed and either run continuously for 20 minutes or until the user pushes the Turbo button again, at which point the fan speed will return to the original setting.

Heating Mode

In this mode, the system heats the room air with the indoor fan running at either the selected speed or on Auto. As in the cooling mode, the indoor fan will run continuously unless interrupted by the cold blow algorithm. This algorithm will not allow the fan to run if the indoor coil temperature drops below a preset value.

The sleep function can be selected while the unit is running in the Heating Mode. Defrost is controlled by the on-board microprocessor.

Compressor and Fan Operation

The compressor and outdoor fan cycle on and off based on the actual room temperature versus the set point as shown below. When the compressor starts, it will run continuously for 7 minutes even if the set point condition is satisfied.

The 4-way value is energized in heating and will stay energized for 2 minutes after the mode is changed into a non-heating mode.

Compressor on outdoor fan off

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Room te

m

p. down

 

 

 

 

 

 

 

 

 

Compressor off

 

 

Room

te

mp. up

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

outdoor fan on

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ts

Ts+3.6*

Ts+5.4*

T

T= Room Temperature TS = Set Point Temperature

* For 9k & 12k Units Only. For 18k and 24k units, numbers will be 5.4 and 7.2 respectively.

A08109

Fig. 27 – Compressor and Outdoor Fan - Heating Mode

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Carrier 38MVC, 40MVC, 38MVQ, 40MVQ service manual Modes of Operation

40MVQ, 40MVC, 38MVQ, 38MVC specifications

The Carrier 38MVC, 38MVQ, 40MVC, and 40MVQ are advanced air-conditioning systems designed for both residential and commercial applications. These units are recognizable for their commitment to efficiency, reliability, and comfort, making them ideal choices for various environments.

One of the standout features of these models is their high energy efficiency ratings. Both the 38MVC and 38MVQ boast Seasonal Energy Efficiency Ratios (SEER) that exceed industry standards, delivering substantial energy savings over time. The 40MVC and 40MVQ models also continue this trend, featuring enhanced efficiency that translates into lower utility bills and a reduced carbon footprint.

These air-conditioning units utilize Carrier's innovative inverter technology, which allows for variable speed operation. This means that the compressor can adjust its speed according to the cooling demand, resulting in smoother temperature control and less energy consumption. The inverter technology not only maximizes comfort but also contributes to quieter operation, as the systems can run at lower speeds when full capacity is not required.

In addition to efficiency, the Carrier 38MVC, 38MVQ, 40MVC, and 40MVQ are equipped with advanced filtration systems. These systems work to purify the air by reducing allergens and pollutants, ensuring a healthier indoor environment. Some models also come equipped with smart connectivity options, allowing users to control their air conditioning remotely via a smartphone app. This feature adds convenience and helps monitor energy usage effectively.

With durable construction and high-quality components, these units are designed to withstand the test of time, reducing the need for frequent repairs or replacements. They are also built to operate quietly, so they can provide comfort without disturbing the peace of the indoor environment.

In terms of installation flexibility, the Carrier 38MVC, 38MVQ, 40MVC, and 40MVQ can be easily integrated into various existing HVAC systems, thanks to their compatible size and design. This adaptability makes them suitable for a wide range of applications, from small residential homes to larger commercial spaces.

Overall, the Carrier 38MVC, 38MVQ, 40MVC, and 40MVQ models are engineered with cutting-edge technologies that prioritize efficiency, comfort, and ease of use, making them an excellent choice for those looking to enhance their indoor climate control solutions.