Power quality opinions

Sense Labs
8

To: @chestnut

  1. Take a very up-close detailed expanded wattage graph (screenshot using your phone APP) of a single event or several single events. Post those pictures on the forum. Look at the ‘max peak starting watts’ versus the ‘running wattage’. My starting peak watts was 6500 watts. After installing a ‘Hard Start kit’, my starting watts was reduced to 3500 watts. I had a huge argument with my HVAC installer. He insisted that there was no problem when he tested using his cheap voltmeter. You need screenshots and lots of them. I was able to get the HVAC manufacturer (American Standard) to upgrade and install my Hard Start kits for free.

  2. As for dips on L1 versus L2: Maybe when your compressor kicks in, so does the outside fan. The fan runs on 120Vac. Maybe the problem is more with the fan. Do you hear a squeal when it initially starts up? Are there leaves or debris on the fan blades? Does the fan bearing need oil? You should see two distinct starting peaks when your outside AC kicks in compressor, then fan.

  3. Is this a concern? Maybe not, but you might be stressing other sensitive electrical equipment and setting yourself up for premature failure in an area you don’t suspect.

  4. If you have a home generator and it is capable of running your AC, a high peak load on HVAC start-up is going to tax your generator.

  5. My “Run/Start capacitor” and my additional “Hard start kit” use a mechanical relay. (Check, some have an electrical chip that sense startup. Don’t oil those.) When mine were new, they were stiff. They tripped, but not fast enough. The SENSE monitor still saw a high starting wattage. I used CRC-26 electrical spray and some WD-40 to lubricate the mechanical relay. I still had problems for about a week, then the trip became fast enough that the problem went away. Maybe the lube needed time to work.

Hard start kits are $100-$250 depending on brand. What is your AC manufacturer and brand? When was it installed? When was it last serviced? What is the length of wire from your breaker panel to your outside HVAC? What is the wire size? Wire Gauge to HVAC compressor?

PS. I repaired my problem. Now I see the same problem on my neighbor’s HVAC. We are connected to the same bus bars inside our ground transformer. I now have new voltage dips due to his failing capacitors.

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