Jea48
most cases the branch circuit neutral conductor as well as the branch circuit safety equipment grounding conductor terminate on the same neutral/ground bar in the main electrical service panel.... Sub panels will have them separated on two different bars but they still end up tied together at the main service electrical panel via the feeder neutral conductor and equipment grounding conductor. Both connect together at the main panel.
Yeah
I know
I said that already. See above. Ive installed services for both industrial and residential
for years. Years ago.
The OP said this issue happened right after he added another (new?) amp.
Things were ok BEFORE I GUESS.
So one should always look at the last thing (s) which were altered or changed, to find the answer for a problem
. If indeed a problem came as the result of that change. Apparently there is/was an issue following the amps addition to the system.
I had a similar incident a few years back when I added a near new amp, and thereafter a brand new amp. Two in fact. The hum I experienced was attributed to the grounding system in my home. Not the amp (s).
Consequently I said what I said for a reason. Maybe we ought to call Ripleys Believe it or not, here.
Ultimately I had to lift the ground from the dedicated ckt (s) driving the amp (s). Further, I had to also mitigate the CATV connection to the service ground by use of a transformer as mentioned above, as BOTH ITEMS introduced issues to the system. Even though as the OP said too, my CATV was not connected to my then stereo system.
It is however connected somewhere else.
It was connected to the service ground at the power pole, and et al, above
everything gets tied together there
neutrals and commons.
Sometimes an issue has one thing causing the problem, sometimes its predominately one thing that makes you notice it, but sometimes there are also other contributing factors which only raise their heads once the issue is reailized.
The CATV connection outside shouldnt have matter possibly but it did.
In some areas around here some counties make new construction employ two different ground rods. Theres always the risk then of acquiring a difference of potential there. In sandy conditions drainage is severe, reducing the actual ground rod conduction with the earth itself. Rods longer than the eight foot norm would work better perhaps, but Ive seen the value of keeping that area surrounding the rod damp or wet. Especially in times of extended drought or no rainfall.
Sometimes electrical issues defie practical or common sense approaches. So I tend to keep a more open mind and not merely stick strickly to imperical wisdom.
When the electrical contractor I worked for got the contract to build the local Honeywell location, we ran across a problem with numerous ground rods and a variety of ckts. All the rods were in one common area. All solid copper. All 10 or 12 ft long. Some of the ckts wound up with hums. Front to back several times we went thru the ckts finding nothing out of the ordinary. By then the surrounding area had been poured and there was no way to remove the rods
only to relocate them. Instead of reworking all the rods with another install, someone, one of the older sparkys came up with the DIY inductor.
We all had a good laugh at his expense when he told us about it. BUT it worked fine after a few tries. I dont think anyone ever told Honeywell what we actually did to fix the situation though.
So I dont just make this stuff up. Believe it or not.
Regardless, I hope things get figured out
one way or another.
