[mav52]

  Septic Tanks don't have a pump do they?

Some Septic tanks have high level float alarms ( ours does)

[jneutron]

Is everything connected to your system on the new service panel?

It seems the most common thing is when is when safety and circuit ground are looping all the way to the panel. Try touching the amplifier with a hand, and then other devices, see if the hum changes. That'll confirm that issue.

Excellent point.  If two romex lines were run, then the safety grounds in each romex are independent, and form a loop. 

Running a piece of 12/3 with opposite legs to one location and one ganged breaker may or may not meet local code. Only sparky could tell you that.

edit:  On the east coast of the US, we have single bushing transformers on the pole, and the earth carries a decent amount of the neutral current which drives the primary of the pole transformers.  As such, 5 to 10% of the primary current actually travels through the dirt around the neighborhood.  If your cable feed is attached to the earth at a different place than your residential power feed, that could be the pickup mechanism.  This also can be sensitive to industrial draws from the utility, and they do not have to be close to you to affect earth current.  Have sparky look at the bonding where the cable comes in the house.  It must be bonded to the service ground and earthing rod at the service entrance.  Also have him check the water bond just for good measure.

jn

[Speedskater]

I would troubleshoot in three areas:

a] First see if you can track down the intermittent noise. Turn off your circuit breakers one at a time, to see if it's inside your home.  (this may not be fun right now if you live in the area that's having a cold wave).

b] Have the electrician investigate a 'Lost Neutral' problem.  If you live in the city with metal water pipes between homes.  If a nearby home has a 'Lost Neutral' problem, that home's Neutral current could flow through the water pipe to your home's Neutral connection to the power company. The electrician can measure the current flowing through the water pipe.

c] It could be a 'bootleg ground' problem.
This is an article on a simple test:

"Failures in Outlet Testing Exposed"
by Mike Sokol
http://ecmweb.com/contractor/failures-outlet-testing-exposed

[ctviggen]

Try running everything off of one line.  Solved my hum problem.  I also have 2 dedicated lines but can only use 1.

Mark

I ran my own dedicated two lines and have no hum. I did put them on the same phase though.   I also ran conduit to two 20 amp outlets that use isolated ground. 

[jea48]

The cable comes in on the same wall.  It is a brand new installation.  Should I disconnect on the outside or just in the inside will do?  My cable box has always hummed.

Brand new.......

Just there at your indoor receiver.  All you want to do is lift the cable ground from the system.

Dave

Cheeseboy,

I didn't  see a post of yours where you tried what Dave suggested. The cable company's CATV coax cable's shield will definitely cause a ground loop hum if it is not bonded, grounded, properly from the coax grounding block, (located on the outside of the house), to the main  grounding system of the main electrical service.

If you forgot to disconnect the CATV coax from the CATV receiver do so and then check for hum. Also if you have any other CATV receiver boxes in the home disconnect the incoming cable coax cable from those also at the same time as the coax cable used for the H/T.
Jim

[ctviggen]

For all of these ground problems, the best thing to do is to strip the system down to something that has to work.  For instance, an amplifier connected to two speakers, with nothing (other than the speakers) connected to the amp.  If there's no hum, then continue to add one device at a time until there's hum.  The last device added caused the hum.

To do otherwise means there are too many variables.  For instance, I found hum in a set of interconnects between a device and a preamp.   Without my technique, I'd have been there forever trying to figure out the source of hum. 

Having said that, cable from a cable company can be a source of hum.

[Folsom]

One of these might work, actually. You don't need to eliminate the noisy device, just the ground loop. But depending on a few things, you might need something else because the internal resistance of your components may not allow the loop to be eliminated by anything safe and simple. (people sometimes put resistors on ground, but that's a bad idea)

I've been debating the advocacy of just grounding the chassis's together via a few small wires and spades under any screw on the back of the equipment. It's sort of ghetto, but not everyone likes to dig into their equipment.

[jea48]

If the OPs ground loop hum  problem ends up being caused by a difference of potential, voltage, between the CATV cable company's coax cable and the equipment ground of his dedicated branch circuits I would recommend using a ground loop isolator like the Jensen VRD 1FF.
http://www.cs1.net/products/jensen_transformers/VRD-1FF.htm

I would still make sure the CATV coax cable grounding block is bonded, grounded, correctly to grounding electrode system of the main electrical service. The CATV coax grounding block is there for lightning protection.
Jim

[Folsom]

Jim, that may eliminate the noise but if he gets the equipment to speak to eachother at ground potential he'll have overall improvements. As in both would be smart.

[Cheeseboy]

Brand new.......

Cheeseboy,

I didn't  see a post of yours where you tried what Dave suggested. The cable company's CATV coax cable's shield will definitely cause a ground loop hum if it is not bonded, grounded, properly from the coax grounding block, (located on the outside of the house), to the main  grounding system of the main electrical service.

If you forgot to disconnect the CATV coax from the CATV receiver do so and then check for hum. Also if you have any other CATV receiver boxes in the home disconnect the incoming cable coax cable from those also at the same time as the coax cable used for the H/T.
Jim

Thanks I've been very busy at work.  Last night I disconnected the cable and found the poor ground installed from the cable company to be a large culpret.  The ground was connected to a pipe in the front of the house.  I don't know if this is really a ground.  I emery clothed the pipe and reconnected the clamp.  Still noisy.  I rewired the ground to the newly installed pipes for the new AC.  Problem solved temporarily.  The ground noise went away and returned later that night when all of the family were busy spinning the electric meter.  I will call the cable company and ask them to ground this box properly. 

I think I have many problems at play here.  I believe that the wireing downstairs is done such that GFI's are most likely a bootleg problem.  Additionally the pipe connected to the cable ground could be a lost grounding opportunity.   

How can I find a suitable ground for the cable box?

Can I simply disconnect the ground wire on the new installed AC lines and avoid the bootleg issue?

Steve

[Cheeseboy]

If the OPs ground loop hum  problem ends up being caused by a difference of potential, voltage, between the CATV cable company's coax cable and the equipment ground of his dedicated branch circuits I would recommend using a ground loop isolator like the Jensen VRD 1FF.
http://www.cs1.net/products/jensen_transformers/VRD-1FF.htm

I would still make sure the CATV coax cable grounding block is bonded, grounded, correctly to grounding electrode system of the main electrical service. The CATV coax grounding block is there for lightning protection.
Jim

Would this solve other in house grounding issues as well?  This could be my silver bullit.  What about the other products listed there?  Would the Jensen Transformer do it all?

[MtnHam]

Call the electrician to come back and figure it out!

[Folsom]

If the noise is coming back when the family is doing stuff, it's because of a loop. It means the ground potential is being screwed with before the amplifier can reference the source.

Your problem is that impedance is making the ground potential matching happen through the junction boxes, not the signal wires.

Unless you have balanced IC's then I'd have to reconfigure my suggestions.

[Cheeseboy]

I Just bought the Jensen VRD-1FF and a jumper cable.  I'm still going to have the cable company come out and run the ground back to the box.   If this does not completely stop the problem I'll run a Jensen Transformer between my Pre amp and my Power amp. 

I am going from unbalanced to balanced from the Pre to the amp.  The amp only has balanced in.  I am useing an adaptor to make the connection today.

Say a prayer.  Cross you fingers, Rub the buddahs belly!

Steve

[konut]

Say a prayer.  Cross you fingers, Rub the buddahs belly!

Steve

There's your problem! You forgot to consult the tea leaves, throw the chicken bones and the I Ching.

[jea48]

Thanks I've been very busy at work.  Last night I disconnected the cable and found the poor ground installed from the cable company to be a large culpret.  The ground was connected to a pipe in the front of the house.  I don't know if this is really a ground.  I emery clothed the pipe and reconnected the clamp.  Still noisy.  I rewired the ground to the newly installed pipes for the new AC.  Problem solved temporarily.  The ground noise went away and returned later that night when all of the family were busy spinning the electric meter.  I will call the cable company and ask them to ground this box properly. 

I think I have many problems at play here.  I believe that the wireing downstairs is done such that GFI's are most likely a bootleg problem.  Additionally the pipe connected to the cable ground could be a lost grounding opportunity.   

How can I find a suitable ground for the cable box?

Can I simply disconnect the ground wire on the new installed AC lines and avoid the bootleg issue?

Steve

 CATV Cable coax grounding block.

*   Is the coax grounding block on the same side of the house as the power company's electric meter?
*   Where is the main electrical panel located from the electric meter?  Example, outside by meter, inside garage? I see you live in California
*  If the coax grounding block and electrical panel are on the same side of the house, approx. how far apart from each other would you say they are?

Please answer above questions for next questions and steps to follow.
>>>>>>>>>>>>>>>>

I think I have many problems at play here.  I believe that the wireing downstairs is done such that GFI's are most likely a bootleg problem.
 

GFIs downstairs?  Could you be more specific? Not sure what you are saying. Do you mean the wiring in the downstairs is old 2 wire only, no equipment ground wire, and GFI receptacles were installed in place of the old worn out 2 wire duplex receptacles? If yes that meets NEC code. A GFI receptacle does not need an equipment ground wire to operate properly. When installed on an old 2 wire circuit there must be a label on the GFI or cover plate stating "No Equipment Ground".
>>>>>>>>>>>>>>>>

Can I simply disconnect the ground wire on the new installed AC lines and avoid the bootleg issue?

NO! Electrically unsafe and Dangerous.

Bootleg issue?


 

[Folsom]

Your stuff is unbalanced, even if the input is adapted. There is no ground connecting your chassises. That's what makes balanced systems not have the problem you do.
 

[Speedskater]

Bootleg issue?

from my reply #22

c] It could be a 'bootleg ground' problem.
This is an article on a simple test:

"Failures in Outlet Testing Exposed"
by Mike Sokol
http://ecmweb.com/contractor/failures-outlet-testing-exposed

[jea48]

Bootleg issue?

from my reply #22

c] It could be a 'bootleg ground' problem.
This is an article on a simple test:

"Failures in Outlet Testing Exposed"
by Mike Sokol
http://ecmweb.com/contractor/failures-outlet-testing-exposed

Hi Speedskater,

Yes I know what a bootleg equipment ground is. My question for the OP is, has he found any receptacle in his home that is wired as any of the illustrations shown in your posted info.

What do we know for sure at this point? IF the OP disconnects the Cable Company's Coax cable from the Cable box the ground loop is broken and the hum stops.

From the OP's description of how the Cable installer bonded, grounded, the CATV coax cable ground block it appears it does not meet any of the approved methods per NEC Code Article 820 lV. Grounding Methods.
 820.100 Cable Grounding.

In my last post to Cheeseboy I gave him a list of question regarding the location of the CATV coax cable grounding block. The answers to the questions will determine the grounding method that can be used to not only meet NEC Code but hopefully will solve his ground loop problem.

Problem with CATV cable installers they are not required to be licensed  by any AHJ and do not have the proper training of NEC approved grounding methods.
Jim

[Cheeseboy]

CATV Cable coax grounding block.

*   Is the coax grounding block on the same side of the house as the power company's electric meter?
*   Where is the main electrical panel located from the electric meter?  Example, outside by meter, inside garage? I see you live in California
*  If the coax grounding block and electrical panel are on the same side of the house, approx. how far apart from each other would you say they are?

Please answer above questions for next questions and steps to follow.
>>>>>>>>>>>>>>>>
GFIs downstairs?  Could you be more specific? Not sure what you are saying. Do you mean the wiring in the downstairs is old 2 wire only, no equipment ground wire, and GFI receptacles were installed in place of the old worn out 2 wire duplex receptacles? If yes that meets NEC code. A GFI receptacle does not need an equipment ground wire to operate properly. When installed on an old 2 wire circuit there must be a label on the GFI or cover plate stating "No Equipment Ground".
>>>>>>>>>>>>>>>>

NO! Electrically unsafe and Dangerous.

Bootleg issue?

No.  The ground for the cable was connected to a pipe in the ground in the front yard.  I temporarily disconnected it and reconnected to the pipeing used for the new electrical outlets.  The AC service box is in the downstairs and inside at the back of the house.  Outside meter with an inside box.  It is an 1100 square foot upstair dwelling.  The cable box is on the North East corner and the AC power Box is on the Southwest Corner of the house.  I'm going to estimate the distance from the cable box to the power box at 80Ft with consideration to the decking and such. 

The wireing downstairs is using modern three wire romex.  The Wireing upstairs is two wire.  When the inspection was done on the house prior to purchase the home inspector indicated that the GFI's downstairs were wired incorrectly.  They were not grounded.  The downstairs is a "Illegal" unit.  It ia all modern construction.  The upstairs is very old and is old style wireing.  There is no labeling on the GFI's