Contactor and capacitor of an air conditioner work together to help power the air conditioner’s fan and compressor whenever the aircon thermostat calls for cool (the capacitor and contactor in the heat pump work the same way).
The contactor is the “switch” that receives a low voltage (usually 24V) signal from aircon furnace to turn on. It’s a standard magnetic relay, which mean thats low voltage flows through a coil inside the contactor to creates a magnetic field, which then pulls down a piece of metal that connects both sides of the high-voltage circuit usually (120V or 240V). Closing the circuit allows high-voltage to power the fan and compressor motors. A contactor with one magnetic coil that links one circuit is called a “single-pole,” if it has two magnetic coils that connect 2 circuits it’s called a “dual-pole,” and so on.
The capacitor is like a “battery” that stores some of that high voltage goodness to create what’s called a “phase shifted current,” which is what causes your fan and compressor motors to spin
The aircon’s capacitor will be either a a single capacitor or dual capacitor. single capacitor only has 2 terminals, and if your unit uses single capacitors, you probably have two of them in your system (one for the compressor and one for the fan). On the other hand, . A dual capacitor has 3 sets of terminals on top: one for the compressor, one for the fan, and a shared “common” terminal for both to use.
When your air conditioning stops working, what you’ll usually notice is that your HVAC fan runs normally, but the air coming out of your vents isn’t cold. If that’s happening to you, the #1 most likely cause is a faulty capacitor in your outdoor A/C unit or heat pump. The second most likely reason is due ti a faulty contactor.
Call us for booking a slot if you are having any issue with your air conditioner at Setapak area : Wangsa Maju, Melati, Melawati, Ulu Klang, Sri Rampai, PV condos, Prima Setapak, Setapak Central.