If your air conditioning unit isn’t turning on, or if it isn’t working like it should, a contactor might be to blame. An improper contactor is one of the most common reasons why an AC does not turn on while other systems look okay. This blog will describe what a contactor is, how to test it, problems you may encounter, and how to know when it needs to be replaced. Let’s get started!
What is a Contactor in an AC Unit?
A contactor is a type of switch that is located inside an air conditioning system. It regulates the current that is supplied to the compressor and fan motor to regulate the speed of the fans. When the thermostat needs cooling, then the contactor is closed, power supplies the compressor and the fan. If the contactor is damaged, it can interfere with the performance of the AC.
Safety Precautions Before Inspecting the Contactor
The following are important safety measures that one should make sure of before checking or working on any electrical component in your AC unit. Here are some essential precautions to follow:
- Turn Off Power: They also recommended always making sure the power is switched off at the mains, which means at the breaker box to avoid taking electrical shocks. This is quite important when evaluating any electrical part of your Air Conditioner system.
- Use Proper Tools: Always embrace insulation when handling a wire especially to avoid touching the live wires accidentally.
- Wear Safety Gear: Use rubber-sole shoes and safety gloves to avoid electrical risks when working on projects that involve electricity.
- Ensure No Moisture: Do not inspect the contactor if there is moisture near the AC unit since this can lead to a probability of electric shock.
After ensuring that the power is off and you are safe, then you can go on and start checking the contactor.
How to Check the Contactor on an AC Unit?
Checking and performing a test on the AC contactor is part of the process of determining problems with AC unit performance. If the contactor is bad it may hinder proper cooling or there will be occasions where the cooling is interrupted. Here’s how to do it:
- Locate the Contactor: Usually, the contactor is placed in the outside unit (the condenser). Open the panel to access it. You will see a large, rectangular component with electrical connections affixed to it.
- Inspect for Visible Damage: Check the physical condition of the contactor perhaps the surface may be worn out or there may be signs of blushing anywhere around it. In other cases, one can observe burn marks, some corrosion, or some of the parts are broken at least then the contactor will be faulty.
- Listen for Clicking Sounds: In particular, when the thermostat calls for cooling, the contactor ought to click while closing to allow power through. The contactor may stop working if you do not hear a click when the system is activated.
- Test the Contactor with a Multimeter: A multimeter is an important tool that is used in testing electrical parts. Switch the multimeter to the ohms or resistance scale on the dial of your multimeter. Now, connect the multimeter probes on either side of the contactor. If the contactor is working, then the values should be near zero most of the time. If the reading is high or has no correlation, it is the contactor that needs replacement.
- Check Voltage: Another way is to take a voltmeter and see whether the contactor is getting voltage when the thermostat turns ON the cooling mode or not. Malfunctioning of the contactor may also be indicated by the presence of voltage but without the contactor closing.
- Inspect the Coil: The coil is the operational component of the switch in the contactor. In case the coil is burnt out then the contactor will not be able to operate. If the coil is present, then it is judged by the presence of deformation or burn marks even if it is cracked.
Common Problems and Troubleshooting
Here are some issues people face when working with a contactor and ways to address these concerns easily. This means that the contactor is making and breaking the circuit to your AC unit and so it is necessary to ensure it is in the correct form.
- Contactor Won’t Close: If the contactor isn’t closing, it might be stuck or damaged. Check for debris or dirt that could prevent the contactor from working. If cleaning it doesn’t help, the contactor may need to be replaced.
- Burn Marks on the Contactor: Burn marks usually indicate electrical arcing. This could be caused by a power surge, or the contactor may be worn out. Replacing the contactor is the best solution.
- No Power to the Contactor: If the contactor isn’t receiving power, the issue could be with the thermostat, the control board, or the wiring. Inspect these components before replacing the contactor.
- Intermittent Cooling: If the AC unit cools intermittently, the contactor may not be closing properly. This can happen due to corrosion or wear on the contact points. Clean or replace the contactor as needed.
When to Replace the Contactor
A contactor is a crucial part of your AC unit that helps control the power to the compressor and fan. If it isn’t working correctly, your AC may not run properly, and could even cause damage to other components.
- Excessive Wear: If the contact points are severely pitted, burnt, or damaged, the contactor can’t function properly.
- Frequent Cycling: If the contactor is clicking on and off frequently, it could indicate a failure to hold the contacts together. This can affect the performance of the AC unit.
- Inconsistent Cooling: If your AC unit’s cooling performance is erratic, and the contactor is not clicking or engaging properly, it’s time for a replacement.
- Burning Smell: If you smell burning or see signs of smoke around the contactor, stop using the unit immediately and replace the contactor.
Conclusion
Checking the contactor in your AC unit is a straightforward process, but it’s essential to do it safely. If you find that the contactor is damaged or not working, replacing it is crucial to keep your system running efficiently. Regular troubleshooting and timely maintenance can increase the efficiency of your AC unit. This will prevent costly repairs in the future.
If you’re not comfortable handling electrical components or suspect a problem with your AC unit, it’s always best to call a professional. The experts at MoreDay are available to diagnose and repair your HVAC system. Contact us for reliable and fast service!
For expert AC unit repairs and maintenance, trust MoreDay to keep your home cool and comfortable year-round. Visit MoreDay for all your HVAC needs!
Related reading: How to Check Surge Protection Device？
