Carrier 40MVC, 38MVQ, 38MVC, 40MVQ service manual Control System, System Safeties, Minute Time Delay

Page 20

38/40MVC, MVQ

CONTROL SYSTEM

The 40MVC/MVQ unit is equipped with a microprocessor control to perform two functions:

1.Provide safety for the system

2.Control the system and provide optimum levels of comfort and efficiency

The main microprocessor is located on the control board of the fan coil unit (outdoor units have a microprocessor too) with thermistors located in the fan coil air inlet and on the indoor coil. Heat pump units have a thermistor on the outdoor coil. These thermistors monitor the system operation to maintain the unit within acceptable parameters and control the operating mode.

SYSTEM SAFETIES

Safety

 

Cooling Only

 

 

 

Heat Pump

 

9K

012K

018K

024K

09K

012K

 

018K

024K

 

 

3 Min Time Delay

X

X

X

X

X

X

 

X

X

Over Current Protection On Compressor

X

X

X

X

X

X

 

X

X

Indoor Coil Freeze Protection

X

X

X

X

X

X

 

X

X

Condenser High Temperature Protection

 

 

 

 

X

X

 

X

X

Indoor Evaporator High Temperature

 

 

 

 

X

X

 

X

X

3 MINUTE TIME DELAY

In order to protect the compressor, there is a 3 minute delay on break even if the control is calling for heating or cooling.

COMPRESSOR OVERCURRENT PROTECTION

Overcurrent protection can result due to any of the following:

SThe ambient temperature is to high S Locked rotor on the compressor

S Blockage in refrigeration circuit (cap tubes, for example) S Outdoor air is blocked or restricted

The compressor current is monitored continuously and protection is provided as shown below:

3sec

5min

1sec

Normal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current down

 

 

 

 

 

 

 

 

 

 

 

Compressor off

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(after 3 seconds)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Compressor off

 

 

 

 

 

 

 

 

Current up

 

 

 

 

(after 5 minutes)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Outdoor fan

 

 

 

 

 

 

off (heating)

 

 

 

 

 

 

Indoor fan low

 

 

 

 

Indoor fan: On

 

 

 

 

speed (cooling)

 

 

 

 

compressor: On

 

 

 

 

 

 

 

outdoor fan: On

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A08117

Fig. 19 – Compressor Overcurrent Protection

If the compressor is stopped 4 times at the 5 minute limit or 1 time at the 3 second limit, the system will be locked off and the main power will have to be reset before the system can be restarted.

Time Limit

 

 

Compressor Current

 

 

38MVC(Q)009---1

38MVC(Q)012---1

38MVC(Q)012---3

38MVC(Q)018---3

38MVC(Q)024---3

 

3 SEC

14 A

18 A

11 A

14 A

23 A

5 MIN

12 A

16A

9 A

12 A

21 A

I SEC

10.5 A

14 A

7 A

11 A

18 A

NORMAL

9 A

12.5 A

6 A

10 A

16 A

20

Image 20
Contents 38MVC/40MVC 38MVQ/40MVQ IntroductionModel Number Nomenclature Indoor UnitStandard Features and Accessories Coil Specifications Cooling only UnitsSystem Model Number Specifications Heat Pump Units OutdoorService Valve Locations Clearances Indoor Electrical Data 53MVC/MVQ System Operating Envelope ChartSystem Operating Envelope Connection Diagrams Connection DiagramsWiring Diagrams Wiring Diagram 38MVC009----1 W/ 40MVC009----1Wiring Diagram 38MVC012----1 W/ 40MVC012----1 Wiring Diagram 38MVC012----3 W/ 40MVC012----3 Wiring Diagram 38MVC018----3 W/ 40MVC018----3 Wiring Diagram 38MVQ009----1 W/ 40MVQ009----1 Wiring Diagram 38MVQ012----1 W/ 40MVQ012----1 Wiring Diagram 38MVQ012----3 W/ 40MVQ012----3 Refrigeration Cycle Diagram CoolingRefrigerant Charge Refrigerant LinesGeneral refrigerant line sizing Using Vacuum Pump System Evacuation and ChargingMinute Time Delay Control SystemSystem Safeties Compressor Overcurrent ProtectionCondenser High Temperature Protection Indoor High Temperature ProtectionSequence of Operation Indoor Coil Freeze ProtectionModes of Operation Auto Fan DefrostForced Cooling Operation Dry Dehumidification ModeManual Operation Troubleshooting Diagnostic HierarchyRequired Tools Recommended StepsChart 1 Indoor FAN Speed OUT of Control YesChart 2 Temperature Sensor Chart 3 Compressor Overcurrent Protection Chart 4 Indoor Unit Communication Error Size 9K and 12K Chart 5 Outdoor Unit Protects Chart 6 Indoor Unit Communication Error Size 18K and 24K Chart 7 Unit not RUNNING, no Diagnostic Code Chart 8 Unit not Running Optimally Chart 9 Unit not Running Optimally HP in Heating Chart 10 Compressor Chart 11 Outdoor Motor Chart 12 Reversing Valve Chart 13 Receiver BoardAppendix Table of Contents Description Number Appendix38MVC009--- --- ---1/38MVC012--- --- ---1 Control Board Input or Output Value40MVC009--- --- ---1/40MVC012--- --- ---1 Control Board 38MVQ009---1/38MVQ012--- --- ---1 Control Board38MVC012--- --- ---3 Control Board 40MVC012--- --- ---3 Control Board38MVQ012--- --- ---3 Control Board 40MVQ012--- --- ---3 Control Board38MVC018--- --- ---3 Control Board Control BoardA6 Characteristics of Temperature Sensor Temp. ˚F/˚C Resistance KΩ9K & 12K Units 18K & 24K UnitsCatalog No.38---40MV---1SM
Related manuals
Manual 10 pages 47.7 Kb

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.