Alleviating the effects of heat and humidity should be a priority when living in the Philippines. That is why a lot of people have been buying air conditioners to stay comfortable and avoid getting a heatstroke. However, aircons have a high energy demand to operate and are used for many hours at a time. This puts immense pressure on your main circuit breaker (MCB), which might cause it to trip and affect the other electronics in your house.
A circuit breaker is a device that interrupts (or trips) the flow of electricity when it detects excess current stemming from an electrical overload or a short circuit. This protects your house wiring from damage and will save you from an electrical fire. Since air conditioners have a high amperage draw, it is recommended to install a separate circuit breaker for your aircon to avoid it from tripping your MCB.
In this article, I will discuss why your air conditioner needs a separate circuit breaker, and how to choose the appropriate circuit breaker size for your unit.
How does a circuit breaker work?
A circuit breaker is a fuse-like device that protects your home from electrical fires by disrupting the flow of electricity when it detects an abnormally high electrical current. However, unlike a fuse which needs to be replaced every time it trips, a circuit breaker can be reset after some time has passed.
Circuit breakers have contact points that, if closed, allows the regular flow of electricity to run from electrical mains to whichever circuit it is connected to. When it detects a dangerous fault in the current, the circuit breaker opens these contact points, thus disconnecting the circuit. This prevents electricity from flowing further, thus protecting your house’s circuits from electrical fires.
While circuit breakers are typically arrayed together in the main control panel board, you can also get a separate circuit breaker installed for a high-powered appliance that is too far from the MCB. One such appliance is the air conditioner, but why so?
Why an aircon needs a separate circuit breaker
Air conditioners are notorious for their high energy demands. Apart from its high wattage, aircons also have high amperage. The amperage is the measure of strength of an electric current based on the number of electrons flowing through a circuit. The more electrons in the circuit, the more heat is produced.
Now, it is normal for an aircon to have a high amperage. However, it will be susceptible to damage during low voltage fluctuations. Voltage and amperage are inversely related, that is, when the voltage drops, the amperage increases, and thus heat, which makes electrical fires likely to happen if the flow of electricity is not stopped immediately.
Also, if other appliances are connected to the same circuit as an aircon, the amperage draw may be too much for the circuit to handle, and thus the breaker will trip. This is the primary reason why your aircon needs a separate circuit breaker.
Apart from safety, the convenience aspect should not be left out as well. If your air conditioner is connected to the main breaker, the other areas of your house will get its power turned off if the air conditioner trips the breaker. Having a separate breaker for the AC localizes the tripping to the unit itself without the other areas being affected.
Note: if you have multiple air conditioners in your home, each unit must be connected to a different circuit breaker.
How to know the appropriate circuit breaker capacity for your aircon
As stated earlier, the capacity of your circuit breaker is dependent on the power of your air conditioner. If the capacity of the circuit breaker is too low, then it could trip even if no shorts or overcurrent is detected. Circuit breakers are divided into the following capacities: 15, 20, 30, 40, and 50. So, which one to choose?
According to the Philippine Electrical Code (PEC), the standard load capacity for special purpose outlets (e.g. aircon outlets) is 30A. This means that the common air conditioner capacities available in the Philippine market (0.5HP to 2.5HP) need to be connected to 30A circuit breaker regardless of horsepower. The only time you should opt for a higher capacity circuit breaker is if your AC has a higher cooling capacity than 2.5HP.
For air conditioners above 2.5HP, you need to do the following calculations:
[(Horsepower * 746) ÷ Rated Voltage] * 250%
The horsepower figure is multiplied by 746 to convert it to watts. The product is then divided by 230V, which is the rated voltage in the Philippines. The number you will get here is now in amperes. Afterwards, add a buffer of 250% to the amperage as the PEC states that appliances equipped with a motor with a continuous load (like and aircon) should have this provision.
In this example, we will be calculating the size of the required circuit breaker for a 4.0HP floor standing air conditioner:
Calculation: [(Horsepower * 746) ÷ Rated Voltage] * 250%
Step 1: [(4.0 * 746) ÷ 230] * 250%
Step 2: (2,984 ÷ 230) * 250%
Step 3: 12.97 * 250%
Your unit’s amperage is 32.4A
In the example above, the amperage is 32.4A, which might lead some to believe that a 40A circuit breaker will be enough to cover the requirements of the aircon. However, you also have to factor in the 80% demand factor for circuit breakers, and since 80% of 40 is 32, it may not be enough to cover the 32.4A amperage draw of your unit. Hence, the safest thing to do is to install a 50A circuit breaker for your 4.0HP unit.
Can you DIY a circuit breaker installation?
You must be careful with everything that involves electrical, especially if it covers your entire house. That is why I recommend that you do not install an air conditioner circuit breaker on your own. Instead, call an electrician to install it for you.
If you have bought a split type air conditioner, the AC installer may be able to install the circuit breaker for you. Do not risk your family’s safety to save a few pesos by DIY installing a circuit breaker.
During my stint working for a home appliance company, the question “do I need a separate circuit breaker for my aircon?” is the one that I have encountered the most. The answer is yes, you need a separate circuit breaker for your aircon. And according to the PEC, the load capacity should be 30A.
I hope this article has answered your question, and when in doubt, contact a licensed electrician to install the circuit breaker. Safety should always come first!
Miguel Mores worked for 5 years as a member of the product management team for a home appliance company in the Philippines. He started 101appliance to answer the most common customer questions that he has encountered during his time in the industry. He now works in the digital marketing field and manages a small online bookstore on the side.