The Lights Are Dimming When the AC Turns On

Condenser Fan

Air conditioning is almost an indispensable part of every American home, especially during the sweltering summer months. Among the array of air conditioning units in Atlanta, finding a system that adequately caters to indoor climate control is essential.

However, a common concern associated with these units is the noticeable dimming or flickering of lights when the AC powers on. While a slight flicker is generally benign, recurrent or pronounced dimming may require attention.

Why Lights Dim or Flicker

The phenomenon of lights flickering when the AC turns on is often due to the substantial electrical load incurred when powering on a large appliance like an air conditioner. On average, your lights might dim about 5% momentarily. The towering AC system momentarily diverts energy from other electrical entities, causing a brief dimming effect in your lighting system. This transient change is usually harmless.

When To Seek Professional Inspection

The rule of thumb, as conveyed by seasoned AC technicians, is:

  • A slight flicker or dimming lasting a few seconds is normal.
  • The dimming range should be about 3–5% only.
  • Concern should arise if the dimming is severe enough to nearly shut off the lights or if lights flicker on and off rapidly. Three common culprits behind such anomalies include:
  • Damaged AC Capacitor: Similar to a car's battery, the AC's capacitor aids in its operation. A faulty capacitor may cause a substantial electrical draw, leading to about 30–50% dimming when the AC is activated.
  • Loose or Damaged Wires: Imperfect wiring can induce lights to flicker when the AC comes on as it hinders electrical flow through home appliances. The scenario exacerbates when the AC activates, further straining the faulty wiring.
  • Overloaded Circuits: Sometimes, the AC shares a circuit with other appliances. According to the National Electric Safety Code, major appliances should have dedicated circuits to prevent overloading. Circuit overload not only causes flickering but also poses a fire hazard if left unchecked.

Maintenance and Solutions

Routine maintenance of your AC, especially by reputable service providers, can mitigate such issues. During AC maintenance, technicians inspect and clean the cooling system, ensure electrical connections are secure, check the thermostat, and ensure the system operates efficiently without overloading the electrical system.

Conclusion and Action Steps

Understanding and addressing the electrical quirks in your home when the AC operates can prevent potential issues down the line. If your residence experiences significant light dimming when the AC turns on, it might be time to call in the professionals.

Moncrief Heating & Air Conditioning is your go-to solution for full-service HVAC installation, repair, and maintenance in the greater Atlanta area. We devise custom solutions aligning with the comfort, health, and budgetary constraints of every home and business. Reach out to us for a thorough inspection and ensure a seamless operation of your air conditioning unit in Atlanta.