First let me say that I'm a newbie and have zero electrical experience. I'm an IT Guy and thought "Hey, its electronic, so I can probably figure it out." I appreciate any feedback/suggestions you folks may offer. I have installed a $20 Honeywell thermostat and the air blows, but not cold. The AC Unit wont kick on outside. This only happened after I installed this new STAT. I have a 5 wire bundle and an additional 2 wire bundle. As you can see from my photos, I have connected 4 of the 5 wires, based on the obvious W to W, R to R, etc etc markings. I do not know if I need to hook up the black. I am almost sure that the reason I do not have the AC Unit kicking on, is due to the 2 wire red and white not being connected. My question is, where do the 2 wire red and white wires connect on the Thermostat? Again, I really appreciate you folks taking the time to reply Everything at the furnace looks good. There seems to be an extra cable at the thermostat, which might be an old abandoned two wire thermostat cable.

You'll also notice the C wire just hanging out, which should be either used or capped off. besides that, everything looks good at the thermostat too. I'd investigate where that abandoned cable goes. I'd start by looking in/near the furnace. But based on what you've shown, I wouldn't suspect the problem is with the wiring.Browse other questions tagged electrical thermostat or ask your own question. 1,472 posts, read 2,686,453 times Originally Posted by seque5tra After they come out and go through all the other factors and so fort and finally get down to replacing (probably repairing) the section of faulty wire... it should stillbe under their minimum charge. But when you call? Cut the soap opera drama and get down to "just the facts" when asking for help. Zippyman, thank you for your insight! Thanks for your help, MrRational. And yes, on the phone I just ask about the cost of the thermostat wire. it costs us $100 just to drive a service vehicle from our shop to a customers house.

so take that into consideration before you call someone a crook. Truth be told, some of your colleagues (people in the HVAC business) are crooks. I am shopping around for a contractor to replace the furnace and a/c unit in my home and the disparity in price is astronomical. Some of them just walk into my home and automatically assume they can earn their annual salary off this one gig. Total waste of my time. The job isn't major by any means, one would expect that having an informed customer wouldn't inflame you. If it costs your business more than $100 to do a 15 minute repair, the problem isn't the customer, it's your excessive overhead. An honest contractor doesn't need to gouge on minor repairs - they'll get referrals & repeat business if they show a little mercy once in a while. That kind of repair doesn't require any expensive tools, training, or certification, and it's no more dangerous than replacing a doorbell button - they're both 24 volt systems. It doesn't cost us $100 to do a 15 min repair;

that's just for the drive over. this is close to the national average. you need to understand that a service company doesn't get 8 billable hours a day. they won't be worth the money lost. so why is the homeowner calling someone else to do it?How to Wire an A/C Unit Wiring an A/C unit involves installing a double-pole, 240-volt circuit breaker in the main service panel, running a 240-volt cable to the A/C's location, installing a safety-disconnect switch there, and then running weatherproof flex from the switch to the A/C's terminal box. how to make a window ac unit quieterThis isn't an especially difficult project but it will involve applying for an electrical wiring permit from your the building department, working with the NEC (National Electrical Code,) and using some basic applied math. central ac sizing guide

The most difficult part of this project will be routing the cable from the service panel to the safety-disconnect switch. This may involve fishing the cable through finished walls and floors/ceilings. Locate the nameplate on the A/C unit and note the specifications for the "Continuous Duty Full Load Current" and/or the "Branch Circuit Selection Current." Calculate the minimum required Ampacity (Ampacity refers to the maximum current that a conductor of a given size can carry safely) for the branch circuit conductors by multiplying the "Continuous Duty FLC (Full Load Current)" or the "Branch Circuit SC (Selection Current,)" whichever is greater by 1.25, per NEC Article 440.32.ac dc power supply connectors guide Compare the computed value with the values given in NEC Table 310.16, column one. If the computed value falls between two listed values, select the wire size with the next higher rating.

Calculate the minimum rating for the safety disconnect switch by multiplying the "Continuous Duty FLC" or the "Branch Circuit SC," whichever is greater by 1.15 per NEC Article 440.12(A)(1.) If this minimum rating falls between two standard ratings, select the next higher rated switch. Calculate the minimum circuit breaker rating by multiplying the larger of the two current ratings by 1.25 per NEC Article 210.20(a). Compare this value with the values given in NEC Article 240.6. If the computed value falls between two standard ratings, select the higher rated circuit breaker. Apply for your wiring permit. Don't start the wiring until the permit arrives. Wiring the A/C Unit Mount the safety disconnect switch next to the A/C unit. Route the type UF cable between the service panel and the safety-disconnect switch. Install a cable connector in one of the safety switch's bottom knockouts. Remove 12 inches of the cable's outer jacket and secure the cable in the connector by tightening the clamping screws.

Route the red and black circuit conductors to the top of the switch, strip off ¾ inches of insulation, and attach them to the main switch lugs. Attach the white circuit neutral conductor and the green/bare-grounding conductors to the switches neutral and grounding bars, respectively. Install liquid tight connectors in the switch and the A/C terminal box and make up the flex. Secure the flex to the switch and attach the red and black conductors to the bottom lugs on the switch. Attach the neutral conductor and the system-grounding conductor as you did above in step 8. Attach the flex to the terminal box and make up those connections by attaching the conductors to the appropriately marked terminals. Remove the cover to the service panel and install the double-pole breaker. Install a cable connector and the cable in the service panel. Connect the red and black circuit conductors to the circuit breaker terminals. Connect the neutral and ground conductors to the service panel's neutral and grounding bars.

Only one wire per screw or your installation will fail inspection. Call the local government building department for inspection. EC&M Journal Sizing a circuit breaker. EC&M Journal Code Calculations Article 440 Air Conditioning and Refrigerating Equipment An air conditioning system uses the outside condensing unit to force liquid refrigerant through a metering valve, found in the inside unit's... Wiring an AC electric motor is not particularly difficult if the manufacturer's manual is available. But if the manual cannot be found,... Air conditioner units come in many types such as a window mounted unit, a central air system or units that are called... How to Install a Split AC Unit; How to Wire an Outlet Split Switch; How to Size Wire for a Central Air Conditioner. An air conditioning unit typically has two separate labels. Air conditioning units, while fully protected on the outside by a plastic or metal casing, are a complex web of wires and...

Check the wiring once again to make sure all the connections are ... The run capacitor on an air conditioning unit is... Wiring an electrical alternating current (AC) switch involves some planning and forethought, but is not a difficult procedure. Safety needs to be... Air conditioning condensing units communicate with the furnace via two thermostat wires. The two wires are encased in insulation to make one... It takes no special skills to install a new breaker into your home's main electrical panel. Circuit breakers are not interchangeable or... How to Install an Air Conditioner. Install the mounting brackets that came with the air conditioner unit (be sure to follow... HVAC condenser units allow people to be comfortable in their homes. Using refrigerant, they pull the heat and humidity out of the... How to Install 220V AC Disconnect Switch How Do I Install the Disconnect Box for an Air Conditioning Unit? How to Connect Wiring to an AC Compressor