The surge factor of an air conditioner describes the ratio between its starting wattage (or surge wattage) and its running wattage.
Understanding Surge Wattage
Air conditioners, like many appliances with motors, require significantly more power to start up than they do to run continuously. This initial burst of power is known as surge wattage, and it's often several times higher than the running wattage.
For example, an AC unit with a running wattage of 1000 watts might have a surge wattage of 2000-3000 watts or even higher. The exact value depends on the specific model and its efficiency. According to one source, the surge wattage can be several hundred watts more than the running wattage. For instance, an air conditioner using 3 kWh (3000 watts per hour) might consume around 3800 watts during the few seconds it takes for the compressor and fan motors to start.
Calculating Surge Factor
While surge factor isn't a standardized specification readily provided by manufacturers, you can estimate it by dividing the surge wattage by the running wattage.
- Surge Factor = Surge Wattage / Running Wattage
So, if an AC has a surge wattage of 2000 watts and a running wattage of 1000 watts, its surge factor is 2.
Why Surge Factor Matters
Understanding the surge factor is crucial when:
- Selecting a generator: You need a generator that can handle the initial surge wattage of your AC unit, not just its running wattage. Otherwise, the generator might overload and shut down.
- Sizing Uninterruptible Power Supplies (UPS): Similar to generators, a UPS needs to provide enough power to cover the surge when the AC starts up during a power outage.
- Determining Circuit Breaker Capacity: The circuit breaker must be capable of handling the surge wattage to prevent tripping.
Example:
Let's say your air conditioner has the following specifications:
- Running Wattage: 1500 Watts
- Surge Wattage: 4500 Watts
In this case, the surge factor is:
4500 Watts / 1500 Watts = 3
This means the AC needs three times as much power to start as it does to run continuously.
In conclusion, the surge factor of an air conditioner reflects the ratio between its starting and running power needs, which is important for proper system design and power source selection.
