Arkansas HVACR NewsMagazine November 2022

HVACR NewsMagazine November 2022

Tech News

Here are some tips for diagnosing a tripping breaker: Tripping instantly • Perform a visual inspection of all wires and connections. Look for signs of rub-out, damage, and arcing. • Isolate components and ohm to ground. • If you cannot locate the issue with an ohmmeter, use a megohmmeter to ground (with caution, especially on scroll compressors). • Finally, once you believe you have identified the cause, fully disconnect the shorted component and power the unit back up. Make sure everything else functions. Tripping intermittently or after more than 3 seconds • Measure running voltage and ensure it is within +/- 10% rating. • Measure voltage drop during startup (less than 15%), between the power source, and right at the unit (less than 5% overall). • Measure component amperages while starting and running, and compare to manufacturer specs. • Measure motor and compressor temperatures, and watch for temperature increase over time. Infrared and thermal imaging can assist with this. • Watch for anything that can cause overload, such as failing bearings, belts too tight, or sheaves adjusted for too much RPM. • Measure current right at the breaker; if it remains below the breaker rating and the breaker STILL TRIPS, then replace the breaker. • Visually inspect all electrical connections and ensure they are clean and tight. • Inspect the breaker and bus bar connections. • Check breaker and wiring size.

I also learned recently that AFCI (arc fault) breakers generate heat internally, which means that you will see a hot spot on them with a thermal imaging camera or IR thermometer. Don't replace a breaker unless you know it's failed, and don't condemn a part as being shorted unless you can isolate it out of the circuit and every other component still functions (as possible). Bert showed his troubleshooting process for a breaker that was tripping intermittently in a recent video. You can watch him in action HERE. — Bryan

Bryan Orr, HVAC School (Founder / Podcaster / Dad of 10) Bryan Orr is a

lifelong learner, proud technician and advocate for the HVAC/R Trade. The NewsMagazine encourages you to subscribe to Bryan’s materials. You’ll be glad you did.