Need suggestions please! Electrical noise in my system and it's driving me crazy!

When it rained really hard the other night it was noticeably worse.

You said you have an under ground electrical service.
Pad mount utility power transformer? Yes?
If yes,
Front of house or back of house?
By chance have you ever noticed a ground fiber electrical junction box just inside the property line? Sometimes they are flush with the ground and sometimes, often, the cover and part of the box will be above the ground a few inches. Usually the box will be somewhat centered on the property line of two property lots. Some times it might be on your property or the neighbor’s next door property. If you have such a box good chance your electrical service wires are jointed/terminated inside the box. If the connections are not water proof, which they usually are not, and the Lineman that made up the terminations didn’t keep them high in the box just below the bottom of the cover, then the terminations could have been laying in ground water from the heavy rain. Water will seek its’ own level.

I do have internet coming in over Coax wire and then have CATV going into my OPPO 105D but I’ve unplugged it and plugged it back in with now change. I don’t have cable, just internet, so only the OPPO is hooked up.

Unplugged? Do you mean you physically disconnected the CATV Cable Providers Coax cable "F" connector from what ever it connects to?

What kind of neighbors do you have around you? Neighbors that are/maybe fed from the same utility power transformer as you. Any of them running a business say out of their garage? How close are you to any commercial business from your home.

Did you ever contact the utility power company and talk to them about your problem?

Edit to my post above.
In reference to whether your electrical service line is terminated in an inground jct box.
If the pad mounted power transformer is on an utility easement area of your property or a neighbor’s on either side of you, there is a good chance your service is ran directly to the transformer.

Eric said:

erik_squires
2,549 posts                                                                  09-01-2017 10:26pm

You don’t by any chance have multiple ground rods placed far apart?

Eric,

Per NEC the bare minimum distance ground rods can be earth driven apart from one another is 6ft. Further apart than 6ft is even better. General rule of thumb is you want the ground rods at least (2X) the length of the rod/electrode from one another.

ALL ground rods must be connected together and connect with one wire to one point, that being the electrical service entrance neutral conductor. NEC defines this as being one grounding electrode. The service entrance neutral conductor shall also be bonded, connected, to the metal enclosure of the electrical service equipment. (At one point only. The neutral conductor shall not be connected to ground at any point there after.)

What you don’t want, and maybe that was the intent of your post, is to have more than one earthed electrode, (as defined by NEC as I stated above), that is not connected directly to the electrical grounding system. An example of an indirectly earth ground connection would be the earth grounding connection of the grounding block for the coax shield of a CATV company’s coax cable. Or a Dish Satellite system. NEC code requires the grounding block shall be bonded, connected, the main grounding system of the electrical service. If the distance is greater than specified, there in the length of the ground wire used, A ground rod must be driven in the earth and a minimum #6 copper wire connect the ground rod to the main electrical service grounding electrode system. The main reason is for lightning protection.

Here is usually the case though. The electrical service maybe on one side of the house and the SAT Dish or CATV provider incoming coax cable and grounding block on another side of the house. Per NEC code the installer is supposed to drive a ground rod. A ground wire is installed from grounding block the the rod. THEN the installer is required, by code, to connect the ground rod to the main grounding electrode system of the electrical service by a minimum size #6 copper ground wire. How many installers install the minimum #6 copper ground wire?
So now two separate earth electrodes exist that will have a difference of potential, voltage, between them.

The coax cable, cable shield, will connects to the grounding block, and the other end connects to a piece of equipment like a SAT or CATV receiver box, and or modem. In some configuration a wire interconnect/s and or video cable will connect from the receiver box to audio and or audio/video equipment that uses a 3 wire cord and plug plugged into a grounding type wall outlet. A ground loop circuit is established. Complete with ground loop hum. Maybe some buzzing to boot too.

.

gearheadmac said:
"When it rained really hard the other night it was noticeably worse."

In my previous post I gave an example what may have been the reason why.
Another might be, (Eric, your post got me thinking about this one.)

More moisture content increasing ground rod to earth conductivity.

As a rule that would not cause the buzz/hum sound the OP is hearing through his speakers to worsen.... JMHO....
But what if there is corrosion in the one or more of the connections in the service neutral conductor somewhere from the utility power transformer through the outside meter socket? (I would rule out the connection in the main 200 amp electrical service panel because the OP said the electrician checked all connections for tightness, and I assume corrosion.)

Any arcing in a feeder conductor connection that feeds an electrical panel could cause an electrical noise buzz in audio equipment that is fed from that feeder by way of the electrical panel, imo. Like RF it would be transferred through the electrical wiring of the house. Again JMHO....

( I should note here, only the imbalanced 120V loads of L1, leg, to neutral, and L2, leg, to neutral, return on the service neutral conductor back to the source, the utility transformer. Depending on how well the 120V loads are balanced across L1 and L2 as a rule the service neutral conductor will not carry all that much current back to the source.)

Current will take any path provided to get back to the source if a path is provided. It prefers the path of least resistance, but it will take any path provided.
If there possibly is corrosion or even if a connection is not tight somewhere in the service neutral conductor, the grounding electrode, (ground rods), for the electrical service could carry some neutral current through the less resistive soil, due to the rain, back to the source, the utility power transformer. But I don’t think that would amplify the OP buzzing sound problem he is hearing through the speakers of multiple audio systems in his home. If anything it probably should have lessened the buzzing sound. (Parallel path provided.)
(Note: Usually the transformer neutral, at the utility transformer, is bonded, connected, to earth to an earth driven ground rod inside the wire connection compartment of the transformer.Transformer steel enclosure is also bonded to the ground rod.

Cut to the chase..... I would look to see if a ground rod was driven for the grounding block of the CATV system coax cable shield. If so I would further check to see if its’ installation meets bare minimum NEC code standards/requirements.
If improperly installed that might/could account for why the OP found the night it rained really hard the buzzing sound was worse. (Better ground rod to soil conductivity. Also less soil resistivity due to more soil moisture content.) The shield of the CATV coax cable could have been/was carrying neutral current. Not only the shield but the branch circuit equipment grounding conductor that was part of the coax cable shield ground loop circuit. JMHO of course...... It would be interesting to know, what if, the OP had disconnected the CATV coax cable at the point ahead of the coax signal splitter that feeds the internet Modem and coax cable/s to CATV receivers elsewhere in the house the night of the heavy rain. Though I did suggest in my earlier post to totally disconnect the CATV coax cable from any thing it is connected to.

(Though even the next day the buzz/noise should have still been worse than before the heavy rain. That kind of makes me go back to my previous post.)

~ ~ ~ ~

At this point all conjecture. The more info the OP can provide the better.

@ gearheadmac ,
Is the main service disconnect breaker inside the 200 amp electrical panel inside the house or outside the house near the electric meter? Or possibly inside a common metal enclosure with the electric meter?

Jim

@erik_squires,

My apologizes for misspelling your name in my last post.

Best regards,
Jim  

nutty
1,212 posts 09-03-2017 1:29pm

I also recently eliminated a hum by disconnecting my CATV from my system. After
re-grounding it, removing the ground and trying power conditioners, I could not eliminate it until I unhooked the coax from the system.

By re-grounding it I assume you are referring to the CATV coax cable grounding block. Please explain in detail how you re-grounded it.

Sometimes even though the grounding block is well grounded to the main grounding system of the electrical service a difference of potential, voltage, may still exist between the shield of the coax cable and the wall receptacle outlet safety equipment ground where the audio/video equipment is located, and plugged into.

"Well grounded"? The least resistive path, best conductivity path, possible?
The connection made at the grounding block must clean and tight. Both the wire and the inside of the lug of the grounding block must clean and free of any corrosion. Corrosion can add series resistance. The best place for the other end of the ground wire to be connected is as close as possible to the electrical service main disconnecting means equipment. Sometimes that may be on the outside of the house or on the inside the house, on an outside wall. NEC code requires that the ground rod/s, for the earth connection of the electrical service, be driven outside the house in close proximity to the main service panel. So whether the main electrical service panel is outside or inside you should see a bare copper, #6awg minimum (maybe #4) wire that exits the metal enclose and goes down into the ground where it connects to the ground rod/s. Connect the ground wire from the CATV grounding block to this bare ground wire where ever it is convenient above earth grade. At least a foot or so if possible. To make the connection to the bare ground wire use what is called a split bolt.
Example: http://www.elecdirect.com/split-bolts-grounding-products/split-bolt-connectors/copper-alloy-2-conduc...
This one has a max conductor size for #6 copper. If your bare ground wire is #4 go to the size for #4 copper.
Note: Clean the bare copper wire with sand paper first to a new shiny copper color.

You’re not done yet.... Every "F" connector from the CATV grounding block to the one that finally screws on the CATV cable box must be free of corrosion and tightened wrench tight. (Snug) Everyone of them. Again, to eliminate any series resistance in the coax cable shield conductor from one end to the other.

After all that you still experience ground loop hum.

That can be due to the continuity, conductivity, integrity, of the in wall receptacle outlet branch circuit wiring safety equipment grounding conductor, wire.
If the branch circuit is a standard 15 amp convenience outlet branch circuit every outlet box the branch circuits passes through the wires were cut and then connected together again in "some fashion" to feed the next outlet. Every equipment grounding wire connection could be adding just a little series resistance to the equipment grounding conductor. Not a problem if the wall receptacle outlet for your audio/video system is closest to the feed end, but if it’s closer to the end of the run that could be a problem.

The only way to find out for sure is to open up every single outlet box and inspect the wiring connections. Not only receptacle outlet boxes but there may be ceiling lights on the same branch circuit.

Or you could buy one of these,
http://www.jensen-transformers.com/product/vrd-1ff/

Jim

nutty
1,213 posts                                                                  09-03-2017 5:10pm

jea48,
By re-grounding- I removed the old grounding connectors, (both phone and CATV) at the grounding rod and at the exterior (outside) cable junction box. I Cleaned the stake with a wire wheel, (to remove rust or oxidation) and reinstalled new 12 awg solid ground wire and connectors.

I still had the (((hum))). With the system on and the volumn at a reasonable level, I disconnected the coax from the cable box and the (((hum))) disappeared.

This was my particular situation. I hope it helps.

nutty,

Thank you for your response.

The ground rod you speak of. Did you notice any other ground wires that were connected to it? Like a larger #6 bare or stranded copper wire?
Just a guess the ground rod was originally installed for the phone and later when CATV was installed the CATV installer used the same ground rod.

Unless the ground rod is fairly close to where the main electrical service of the house is located I doubt the ground rod for the phone or CATV is connected by at least a #6 copper ground wire to the main grounding system of the electrical service.

Many people think, including communication provider companies installers, a separate isolated ground rod is all that is needed to effectively ground their systems to mother earth. It is not though. Electrical safety codes require the systems shall be bonded, connected, to the main grounding system of the electrical service. The main reason all ground rods need to be tied, connected, together is for lightning. You also want all electrical systems grounding connected to one common ground.

https://www.youtube.com/watch?v=QPWmULYgONA

nutty
1,214 posts                                                                      09-03-2017 8:02pm

jea48,
The main rod was installed when the house was built. It was installed as the main ground for the home. However as you suspected, it is within a few feet of the main service panel and the Phone and CATV service is all there as well. The main rod is grounded with a large solid wire, 8 or possibly 6 awg. I ran new leads for the phone, CATV within the exterior boxes as well as hard wiring it directly to the main rod. The results were the same. The (((hum))) was present until I removed the coax from the system.

jea48,
By re-grounding- I removed the old grounding connectors, (both phone and CATV) at the grounding rod and at the exterior (outside) cable junction box. I Cleaned the stake with a wire wheel, (to remove rust or oxidation) and reinstalled new 12 awg solid ground wire and connectors.

I still had the (((hum))). With the system on and the volumn at a reasonable level, I disconnected the coax from the cable box and the (((hum))) disappeared.

nutty,

But did you clean the connection on the ground rod, the ground rod clamp, and the solid #6awg copper ground wire for the electrical service? If not how do you know the connection was not corroded? You want the best possible connection you can get/make to the #6 copper ground wire. The other end of the #6 wire is terminated on the neutral/ground bar in the main electrical service panel. The neutral/ground bar is where all the equipment grounding conductors, wires, are connected/terminated.
(Assuming the main disconnect breaker for the electrical service is mounted in the electrical panel)

What you want, need, is zero resistance, (as close to zero as possible), continuity, between the safety equipment "U" shaped ground contact, (of the wall receptacle your audio video/equipment is plugged into), and the CATV coax cable shield/"F" connector that connects to the CATV receiver box.

Instead of connecting the ground wires, for the phone line and CATV coax cable, to the ground rod you should have connected them to the #6 ground wire for the electrical service.
You could use one of these to connect the two wires to the #6 wire. Install it above grade so it can be inspected. Clean the area on the #6 wire with sand paper where you will be installing the ground termination device.
http://www.gordonelectricsupply.com/index~text~5979096~path~product~part~5979096~ds~dept~process~sea...

If you are still living at the same house I would recommend you re-terminate the phone and CATV ground wires. Pick up an Intersystem Bonding Termination as shown in the link above.
You could also use a couple of split bolts instead. See my earlier post for a link.
Though the Intersystem Bonding Termination meets NEC code.

Jim

Edit to my post above.

When I spoke about cleaning the connection of the electrical service’s #6 copper ground wire at the ground rod I should have mentioned with extreme caution. There could be a lethal difference of potential, voltage, between the disconnected ground wire (the Grounding Electrode Conductor) and the ground rod (Electrode) as well from the #6 ground wire to the soil you are contacting with your knees or any other part of your body contacting the earth. Especially if the soil and or grass is moist/wet.

Jim