Why do my Lights Flicker when the Air Conditioner Turns On?

When your lights flicker specifically when the air conditioner turns on, it is usually due to a momentary voltage drop or a circuit issue. Below are the primary reasons this occurs:

• Normal Voltage Fluctuations: Large motors, such as an air conditioner compressor, draw a sudden rush of current when they cycle on. This causes a brief, predictable voltage dip that makes connected lights dim or flicker momentarily. This is generally considered normal and not a safety concern.
• Overloaded Electrical Circuits: If the flickering is persistent or the lights dim significantly, it is a sign of overloaded electrical circuit symptoms. This happens when the air conditioner draws significant current on a circuit that is already near its capacity.
• Loose Service Neutral Connection: While less common, a loose neutral wire at the main panel or utility connection can cause erratic voltage swings throughout the home when large loads like an AC unit are added. This is a serious hazard that can damage electronics or lead to a fire.

What you should do:

1. Redistribute the load: If the flickering is localized to one area, you may need to move other high-demand appliances to different circuits.
2. Professional Inspection: If flickering is accompanied by buzzing sounds, burning smells, or frequently tripping breakers, you should contact a licensed electrician immediately.
3. Circuit Upgrade: An electrician may need to add a dedicated circuit or perform a load calculation to ensure your panel can safely handle the demand of your air conditioner.

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