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Is A Sneaky Wiring Issue Stopping Your AC From Cooling Your Home?

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When you think about your air conditioning system, you're probably thinking about the big and visible components, such as the main blower or the condenser unit. While your system couldn't function without these important parts, it also can't function without its wiring. A correctly wired system ensures your air conditioner can cool your home safely and reliably. 

Unfortunately, wiring issues are a common problem with many residential systems. In a worst-case scenario, faulty wiring can present a serious fire hazard in addition to stopping your air conditioning system from functioning. If you're having issues with your air conditioner, it's important to understand if a wiring issue may be to blame.

Where Are AC Wiring Issues Most Common?

Most central air conditioning systems require mains electrical power at 240v, which means the electrical connector at the outdoor condenser will have two separate 120v lines. In addition to mains power, your air conditioner requires a low-voltage wire that carries a command signal from your HVAC control board and thermostat. This low-voltage wire tells the compressor when to turn on and off.

If you look at your outdoor condenser unit, you should see a heavy watertight conduit known as a whip. This conduit contains the high-voltage wiring for powering the condenser fan and compressor. There should also be one or two smaller and separate wires. These low-voltage control wires carry the signal from your control board.

Since these wires face constant exposure to the elements, they're the most common location for wiring issues. For example, exposure to UV light and constant heating and cooling cycles can often damage the insulation on the low-voltage wiring. Rodents or other pests can also sometimes enter the condenser unit, where they can gnaw on and damage the high-voltage wiring.

How Do You Know if You Have a Wiring Issue?

A tripped breaker is the most common symptom of a serious air conditioning wiring issue. If an energized high-voltage wire contacts the ground or another conductor, it will likely result in a short circuit or ground fault. This situation will trip your breaker to prevent a potential fire. Depending on the specific problem with the wiring, the breaker may immediately trip again when you try to reset it.

On the other hand, low-voltage wiring faults can be much sneakier and harder to diagnose. Fortunately, they're also less dangerous. A low-voltage fault may blow a fuse on your HVAC control board or lead to unusual behavior or inconsistent operation. You may notice your compressor turning on and off at random or not turning on despite the indoor blower running.

While low-voltage wiring faults aren't particularly hazardous, any wiring issue can be challenging to locate and diagnose. Instead of attempting a repair, contact a trained HVAC professional whenever you suspect your system has a wiring fault.

Contact a local AC repair service to learn more.