When an air conditioner is switched on, it can cause a temporary dimming of the house lights for a few seconds. This phenomenon occurs due to a brief increase in electrical demand or a voltage drop in the electrical system. Here's a more detailed explanation:
Starting Current: Air conditioners require a higher amount of electrical current when they start up. This initial surge of current, known as the starting current or inrush current, is needed to power the compressor and other components. The starting current can be several times higher than the normal operating current of the air conditioner.
Voltage Drop: When the air conditioner's compressor kicks in and demands a higher current, it briefly draws more electrical power from the electrical circuit. This increased power demand can cause a slight drop in voltage in the circuit supplying power to the lights.
Resistance in Wiring: The wiring in a building has some inherent resistance. When a sudden increase in current occurs, this resistance can cause a small voltage drop. The longer or thinner the wiring, the higher the resistance and potential voltage drop.
Shared Circuit: If the air conditioner and the lights are on the same electrical circuit, the starting current required by the air conditioner can affect the voltage available for the lights, leading to a momentary dimming.
Circuit Breaker Response: In some cases, the voltage drop caused by the air conditioner's starting current can be significant enough to trigger the operation of a protective device like a circuit breaker or a safety switch. This protective device momentarily interrupts the flow of electricity, causing the lights to dim for a brief moment before being restored.
It's important to note that a slight dimming of lights during air conditioner startup is generally considered normal and should not cause significant concern. However, if the dimming is severe, occurs for an extended period, or if you have other electrical issues, it may be advisable to consult a qualified electrician to ensure the electrical system is functioning properly and safely.