Newer home (2000). Lights dim when heat pump kicks in. There are two 200A panels. Panel A is general lighting and the gas furnace (15A), furnace can not engage when heat pump does, so it's allowed to be seperate. Panel B (not a sub-panel)is heat pump, dryer, oven etc. SE are 4/0 AL XHHW-2 for the ungrounded conductors and 2/0 XHHW-2 AL for the grounded. NOLOX on all AL connections. All neutrals are tight. Neutral and grounds are properly bonded and grounded. The heat pump has a 50A breaker in Panel B with a 60A fused disconnect at the outside unit. Wired with #8 stranded CU from panel to disconnect and same from disconnect to unit. Even if nothing in Panel B is on and only a couple of lights in Panel A are on, the lights will dim when the pump kicks on. What am I missing? Everything appears to be properly sized, connected, etc. There are no other reported or found problems in the home. It also has a large jetted tub (7 ' x 6', 30" deep), when the pump motors are turned on, it does not affect any lights or anything else. It is in Panel B (same as the heat pump). I suspect something in the pump circuit, but what?
Any ideas appreciated.
Bob
