house lights dimming when heat pump turns on

[gar]

191129-1227 EST

On my Sq-D main 200 A panel with copper bus bars I see about 1 mV change for a 10 A change over the length of the bar. At 200 A that would be possibly be 20 mV. If I had a 200 A load I could get a better measurement. A few millivolts change is not going to produce bulb flicker. It takes about a 2 V change and signal known exactly to get good flicker detection.

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[Stevenfyeager]

Thank you all. It is in a new house. Thank you for the suggestions.

 

[junkhound]

No brainer for new house - pick a HP with inverter, no flicker, higher efficiency, lower heating bills, initial cost about the same after installation factored in. Lifetime cost Lower due to higher efficiency.

Note that efficiency is higher not due to anything electrical motor wise, the inverter allows variable speed so the HP can operate at the most efficient point on a Mollier diagram given indoor and outdoor (or ground in case of GSHP) temperatures.