What you will learn from How to Wire an Air Conditioner for Control - 5 Wires article:this article includes a comprehensive list showing thermostat wire terminations for an air conditioner and a source of heat that includes five wires.a detailed description of where each wire goes in the air handler and condenser and what it controls.a detailed diagram illustrating where the wires go for 5 wire air conditioner and heating system control.resource and related links to help you with wiring and installing a thermostat.How to Wire an Air Conditioner for Control - 5 WiresHow to Wire an Air Conditioner for Control - 5 Wires  – The diagram below includes the typical control wiring for a conventional central air conditioning system. It includes a thermostat, a condenser, and an air handler with a heat source. The heat source for a basic AC system can include heat strips for electric heat or even a hot water coil inside the air handler that is fed from a water heater. Every conventional residential AC system uses 24-volts for the control of the system.

All the relays in the system have 24-volt coils.Circuit boards or printed circuit boards found in modern systems utilize 24-volt control which originates from the control transformer. Typical systems that do not use 24-volt control are window unit air conditioners, ductless mini split systems, and baseboard electric heating systems. Honeywell Thermostats Available Here If you are unsure about the control voltage of your system consult an HVAC professional as some appliances use high voltage and this can be dangerous. Related Link: Standard 18 gauge thermostat wire is used for all control wiring.(opens in a new window) How to Wire an Air Conditioner for Control - 5 Wires - Thermostat Wiring DiagramHow to Wire an Air Conditioner for Control - 5 Wires - Breakdown of colors and terminalsThe R terminal is the 24 volt hot feed from the control step down transformer that will power the relay, contactor, or complete the circuit in the circuit board feeding it with 24 volts when the thermostat calls for whatever it is set for.

The W terminal is for heating including the heating for gas furnaces, electric furnaces, boiler systems and the back-up heat for heat pumps.The G terminal is for the blower fan located in the air handler. It is the fan that circulates air throughout the duct work system.The Y terminal is the terminal that will turn on the air conditioner and typically is terminated at the compressor contactor in the condensing unit located outside. how to reset a home ac unitIt will be one of the few control wires (thermostat wires) that will terminate at the condenser in a split system air conditioner and heating system. how to repair a car air conditioning unitTypically, the yellow wire will be ran to the air handler where at the air handler this wire is usually connected to another wire (typically by wire nut but could be connected via a terminal strip in the air handler) and then ran outside to the condensing unit along with at least one other wire in an air conditioner split system set up. used boat ac units

The other control wire will be the common wire need at the compressor contactor where the coil in the compressor contactor needs a hot and a common from the control transformer to work.Finally, the C terminal is the common terminal and this terminal feeds the common side of load from the control transformer.Related Link: Control Circuits for Air Conditioning & Heating - Delve deeper and learn more about HVAC (opens in a new window) Honeywell Thermostats Available HereTerminal Strip where wire terminations are made during installation. Typically inside the air handler.Additional resource links for wiring a thermostat: 1) Thermostat Wiring Colors 2) How to wire a thermostat 3) Heat Pump Thermostat Wiring Chart & Diagram 4) Select the Proper Thermostat for Your HVAC SystemHow to Wire an Air Conditioner for Control - 5 WiresHow to Install a Mini-Split Air Conditioner In this how-to video, keep cool with This Old House plumbing and heating expert Richard Trethewey In this video, This Old House plumbing and heating expert Richard Trethewey explains how to install a mini-split air conditioner.

1. Lay pad on ground, check for level, then set condenser unit on top of pad. 2. Use 1 ½-inch hole saw to drill hole through house for refrigerant line. 3. Feed refrigerant line through hole and into basement. 4. Open up wall in room where air conditioner will be located. 5. Run refrigerant line from condenser up to room. 6. Assemble PVC drain line and run it to room. 7. Pull electrical cable and low-voltage wire from condenser to room. 8. Screw metal mounting bracket to wall at manufacturer's recommended height. 9. Hang the air conditioner unit on the bracket. 10. Make final connections, including refrigerant line, PVC drain and electrical wires. 11. Install the air conditioner's cover. Tools for Installing a Mini-Split Air Conditioner 1 1/2-inch hole saw to make hole for refrigerant lines Level used to level pad that supports condenser unit Drywall saw or jigsaw used to cut hole in interior wall 1. Mini-split air conditioner

2. Ground pad, for supporting condenser unit 3. 1-inch-diameter PVC pipe and assorted fittings, used as condensate drain line 4. PVC primer and cement, used to join together PVC drain line 5. Armor-sheathed electrical cable, provides line-voltage power to the air conditioner 6. Low-voltage wire, sends signal from air conditioner to condenserPlease feel free to copy this air conditioning circuit and cycle diagram and print it out. The component at #1 in this air conditioning circuit and cycle diagram is the compressor. The compressor is the heart of the system; it keeps the refrigerant flowing through the system at specific rates of flow, and at specific pressures. It takes refrigerant vapor in from the low pressure side of the circuit, and discharges it at a much higher pressure into the high side of the circuit. The rate of flow through the system will depend on the size of the unit, And the operating pressures will depend on the refrigerant being used and the desired evaporator temperature.

The component at #2 in this air conditioning circuit and cycle diagram is the condenser. The red dots inside the piping represent discharge vapor. The solid red color represents high pressure liquid refrigerant. Most air cooled air conditioning and refrigeration systems are designed so that the refrigerant will condense at a temperature about 25 to 30 degrees above outside ambient air temperature. When the hot refrigerant vapor discharged from the compressor travels through the condenser, the cool air flowing through the condenser coil absorbs enough heat from the vapor to cause it to condense. If the outside air temperature is 80 degrees, the system is designed so that the temperature of the refrigerant, right at the point where it first condenses, will be about 105 to 115 degrees. Why do we want the refrigerant to condense at this relatively high temperature? So that the air will be very cold relative to the temperature of the discharge vapor, Which will allow the latent heat energy in the vapor to transfer over to that relatively cold air,

And cause the refrigerant to condense. This transfer of heat from the vapor to the flowing air is what makes hot air blow out of your air conditioner's condensing unit. At this stage in the air conditioning circuit and cycle diagram, high pressure liquid refrigerant will flow down the liquid line, through a filter drier that is designed to prevent contaminants from flowing through the system, and on to the metering device. The metering device, component #3 on this air conditioning circuit and cycle diagram, is the dividing point between the high pressure and low pressure sides of the system, And is designed to maintain a specific rate of flow of refrigerant into the low side of the system. If the wrong capacity of metering device is used, or if there is a problem with the metering device, An incorrect quantity of refrigerant will flow into the evaporator. When the refrigerant passes through the metering device, it drops from about 225 psi to about 70 psi,

It also drops in temperature from about 110 degrees to about 40 degrees, And it wouldn't be too inaccurate to imagine it acting like warm soda when you shake the bottle and pop the top off. It shoots out into the evaporator foaming, bubbling, and boiling, And remember, it's at a low pressure, so it's only boiling at about 40 degrees F. And that brings us to the evaporator, component #4 in the air conditioning circuit and cycle diagram. There will be relatively warm air flowing over the evaporator coil, lets say about 80 degrees. The air conditiong system is designed so that the refrigerant will evaporate in the evaporator at a temperature of about 40 degrees, so that it will be cold compared to the warm air flowing over it. The system is designed so that the heat in the warm air flowing over the evaporator will be absorbed by the cold evaporating refrigerant. This cools the air flowing over the evaporator, and is the reason cold air blows out of your air conditioner.