We are having a problem with one of our AC compressors tripping and wearing out breakers. About every 3-4 months the breaker trips and is basically sensitive after that (e.g., I think its worn down) until it’s replaced.
Looking at the graph (below) in IoTaWatt all looks good w/ a max draw of about 2.6kW at startup and then settling to about 1.9kW running. I’m wondering if there’s a much larger but shorter timespan spike happening that’s causing the breakers to wear out.
Is there a way for IoTaWatt to see and log that? Any other thoughts?
What amperage is the breaker rated for? I have to AC compressors (upstairs + downstairs units) connected through a single breaker for ~28 years without any failure. However, as you can see, I do not see any major in-rush current spike like you’re seeing. I wonder if your AC compressor unit has a failing capacitor, or something similar?
That plot is showing time-weighted average of about 30 samples taken over a 15 second period. You can zoom in closer and get the average of about 10 cycles over 5 seconds, but that’s as much resolution as possible with IoTaWatt.
Just to throw in my two-cents, piston compressors usually have a compression release that releases the cylinder pressure when it stops. It’s normal for it to stop on the compression stroke as that’s where the resistance is. If the pressure release isn’t working, it will try to start against a large load and draw a lot of current. With the compression released, it starts easily. Mine makes a hiss when it stops as it releases the pressure. Could be something as simple as a defective or intermittent release valve.