I'm having an issue with flickering LEDs, the PoCo came out and upgraded my service with a brand new transformer and wiring, they did a power survey before and after and said their side is good now. Previously, they noticed some voltage fluctuations, low voltage, given my distance from the previous tranformer. This was definitely fixed as noted by 120 volts consistently inside the house after their upgrade.
Anyway, flickering issue has been reduced (it's house wide, occurs at the same time for all light circuits, suggesting neutral issue) but it still exists. I can make the flickering occur on demand now by plugging a Keurig into a GFCI beside the kitchen sink and turning it on to pre-heat.
It was during this flicker testing that I noticed a few remarkable things:
- When I turn on the microwave (on A leg in the panel) I noticed a voltage drop on A leg from 120.5 to ~118, very reasonable and expected, HOWEVER, I am noticing a voltage increase from 120.5 to ~121.2 on B leg throughout the house. The expectation would be that the B leg does not increase in voltage.
- I turned off the light circuit upstairs to check for a loose connection (I tested every single lightswitch for loose neutrals mind you), however, the circuit was still hot. I had to turn off an adjacent breaker for the same room's outlets in order to make the circuit safe to work on. Turning off the outlet breaker does not stop the lights from working and turning off the lightswitch does not stop the outlets working.
- Switching the lights to be exclusively on B leg made the flickering worse than switching them over exclusively to A leg, flickering still exists, but it's more faint.
I believe #1 and #2 above are related/causing my flickering issue, I believe the flickering issue to be a tell of a loose neutral or something along those lines.
Unfortunately electricians to date have not given a lot of confidence, but, I'm not sure they found the same findings I have now. I've had 5 visits and no success on fixing the flickering.
I have checked all neutrals on the panel, they are tight, as I said before the PoCo checked their side very thoroughly. How can I begin to diagnose this? Could it be a loose neutral anywhere on the A leg, as in, in any junction box for switches or lights? I don't mind checking them all if that helps! I've spent 100 hours on this, another 20 hours is nothing.
TL;DR - With microwave on A leg drops from 120.5V-118V, but B leg increase by .7 volts from 120.5V - 121.2V. Seeing flickering in the house and noticed an unsafe junction box after turning off the correct breaker for said box. Is there a bigger neutral issue?