Power problems.... Ground, dedicated lines, ect

Also, Square D and others make good boxes and breakers; however, I have found that I have replaced more bad Square D breakers than any other brand.

Newer air-conditioning units typically draw less power than the older ones.

It is not unusual for older homes built in the 1950s or earlier to only have 100 amp service panels rather than the common 200 amp service panels found in later homes.

Either of these could cause noticeable dimming at times as could other major appliances.

New homes and newer appliances should not cause this unless you are using near maximum amperage.

A competent electrician can easily check the majority of electrical connections throughout the house and at the service panel. A competent electrician can also check any/all plugs for proper grounding and proper phase at each wall outlet. You can too if you have a good little meter.

Competent is the key word here.

Typical grounding is done at the service panel where the ground wire is actually connected to the neutral bus. Not sure why exactly but this non-dedicated ground connected to the neutral bus at the service panel is also why grounded components induce more sonic harm than non-grounded. A dedicated ground for your components would definitely be worth considering.

Checking connections from the street to the service panel most likely will require your electrical company to perform this service.

Building a system by laying the right foundation is the only way to go. Electrical is the second most foundational element to a well-thought-out-system.

As such proper line conditioning is mandatory. Again, proper being the key word here because most line conditioners either do nothing or induce their own sonic harm. Moreover, very few will filter out bi-directional noise of which digital noise is. Hence, even if your digital source or amps are attached to good line conditioners the chances are better than excellent that the line conditioner is allowing the digital noise generated by the component to go through the line conditioners back into the wall, all the way back to the service panel, and then induce that digital noise into your other components.

Other things to consider are cryo-treated audio grade wall-outlets, wall plugs, IEC connectors, IEC inlets at the back of the components, internal and external fuses, AC cables, ics, and scs.

Oh, yeah, since I was remodeling a room for listening last year I also had 500ft of 12/2 gauge Romex double-cryo-treated for 4 dedicated lines from the service panel to the listening room.

All of which is relatively inexpensive when compared to the price of one good component. That is except for perhaps the line conditioners.

But since proper AC treatment is one of the two foundational elements to building a well-thought-out system just doing the things mentioned above will produce a pristine and musical system that few can match because of what you did to clean up the AC.

Not to mention you get a bit closer to hearing more of every components' true capability.

-IMO

Power quality is something that utility companies are starting to take seriously as they know the grids are loaded with motors, computers, digital electronics, variable speed motors, etc. What these do is poison entire neighborhoods with noisy ac power making the possibility of electronic component failure higher. They already shell out enough in spoilt food payments during blackouts and foresee more liability with power quality problems as well. Chances are that your utility has a power quality figurehead in a cubicle somewhere and they may very well come out and test. You can do it yourself, but the testing equipment costs thousands of dollars. Or you can try the bigger electrical contractors to see if they offer power monitoring services. But there's really very little you can do on the cheap to correct any utility power issue. The only way is a UPS/Converter system or a shielded isolation transformer for the whole house. You talking Lexus sticker price here.

As far as the air conditioner dimming the lights, that is normal to a certain extent. It the lights really dim, what that could mean is the a/c unit could have a worn-out start capacitor. This capacitor gives the a/c unit the surge it needs on startup and if it's bad then all the startup power is sucked up through your panel. If it's an outdoor unit, that draws a lot of current on startup normally. Also, tungsten light bulbs are very sensitive to small voltage drops so the effect is worse than it seems. One of the solutions is to increase the capacity of the house panel to 200-amps if it's already not that. This will lessen the effects of motor start-ups but not eliminate it. The reason is that the utility transformer serving your house is very stingy with current delivery and there is an inherent large voltage drop at your service panel. It's done on purpose so your house won't see a tidal wave of short-circuit current should one of your household motors short out.

Most power quality problems you can check and correct yourself are: the ground connection from your panel to the water pipe or ground rod should be tight and corrosion free,
the feeders at the main panel should be tight at the breaker lugs, the neutral bus should be bonded to the ground bus, the ground bus jumper bond should be tight, all circuit breakers should sit tight, breakers more than 20 years old should be replaced, all circuits should have their own neutral, all circuits with GCFI receptacles should be on a dedicated circuit. Also, these should be on dedicated circuits: refrigerators, microwaves and window air conditioners. Place these circuits at the bottom of the panel to minimize voltage drop to other circuits, especially 2-pole breakers for well water or septic pumps.

As far as testing, a simple 3-light plug-in tester will tell if you're wired correctly. Here's a hint: wherever you see junction boxes, open them up and make sure the wire connector nuts are tight and the grounding is continuous. Also make sure there's no electrical tape UNDER the wire nuts. That's about all you can do yourself without spending serious money.

I called the engineer at Furman and he said I had a ground loop problem. He suggested I call a local TV or Radio station and find out what electrical company they used. Sure enough they ( local TV station electrical contractor) had a mans name who was the "ground loop expert ) The Furman engineer told me that "power problems" for audio/ video broadcast is more schooled on power issues. ( made sense to me ) I will post the findings and or solution when I get the work done.

Ground conduction can be tested with a 'megger'. ask around until you find an electrician that has one and knows how to use it.
I, too, have a 100amp panel and a 20amp line to over 1kw of amplifier. No Problem!
In the old days, my Carver Cube could make the house lights flicker in time to the music! Now, I can turn it up to nose bleed levels without a flicker. And, with the A/C on.