Many air conditioning problems prompt you to call for HVAC repair services. But, if your unit doesn’t turn on or runs continuously unless the power is cut off, it’s probably an issue with your electrical contacts. Your technician can fix it right away, but you need to learn more about the problem so you can catch it before it destroys your AC.
What’s a Contact Assembly and What’s It For?
You can find contact assemblies in a small electrical box inside your AC called the contactor, which looks like a mini circuit breaker. But, unlike the latter, it’s not intended to interrupt a sudden surge of power. Instead, it’s meant to let currents pass through when the unit is switched on, and cut it when the equipment’s turned off.
The contact assembly inside the contactor has 2 metal strips that open and close like a drawbridge. Their default position is they’re separate. But, once you turn your AC on, they connect, letting electricity flow freely from one alloy to another. When this happens, power is distributed to other parts of your unit.
How Can It Get Damaged?
Many things can damage electrical contact assemblies. Since they’re mostly made of metal, they’ll rust when exposed to water, oxygen, and certain acids.
They can also corrode from years of functioning. When their parts open and close hundreds or thousands of times, they rub against each other, destroying their surface layer by layer. This is one of the reasons malfunctioning ACs don’t start. The pair of metal strips decrease in size so much that they can’t reach each other when then they’re supposed to connect.
When they’re already badly damaged, the metal strips lose their electrical conductivity, meaning thatwhen you turn the AC on, the energy that’s supposed to go through the contact assembly discharges into the air.
That event ignites particulates in the environment and produces a powerful flash of light called an arc. This is so hot it can melt plastic insulators and even weld the contact assembly shut. When this happens, electricity endlessly flows from one metal strip to another, unless you unplug the equipment.
Can I Replace the Assembly Myself?
Messing with electricity when you’re not a professional is dangerous. To fix the problem, the whole contactor must be replaced. It’s best to call a trusted HVAC technician to resolve the issue if handling electrical connections and wiring devices isn’t something you were formally educated in.
Something bad is probably happening to your contact assembly if you notice chattering noises or a burnt smell from your AC. A unit that’s heating up too much is also a sign of the same problem. Unplug the equipment and check it for problems before they worsen.
It’s difficult to have issues with electrical contact assemblies, so make sure you’re taking care of your AC with regular maintenance. And, if you ever need to replace the contactor, or want to try out cadmium free electrical contacts, get a new one only from high-quality brands and trustedretailers.