Electrician installed two dedicated AC lines - Hum on both - What to do?

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Speedskater

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On your GFCI (Ground Fault Circuit Interrupter) dual receptacle's.

Downstairs with 3 wire Romex® (Hot, Neutral & Ground) the Ground wire needs to be connected to the GFCI receptacle's.

Upstairs with only 2 wires (Hot & Neutral) no Ground connection to the GFCI receptacle's is required. The little label is required, however most GFCI receptacle's don't have a good permanent way of attaching that label. So it's no surprise that the label is missing.

jea48

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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

The ground for the cable was connected to a pipe in the ground in the front yard.

Well the installer may have done the job half right. That is if the pipe was driven at least 8ft into the earth and is at least 3/4" diameter galvanized pipe or some type corrosion resistant plating. LOL, 5/8 x 8 ft ground rods are cheap.
Unless you watched the installer drive at least 8 ft of 3/4" pipe into the ground I would not trust the pipe is driven at least 8 ft deep into the earth.

The second half of the job I doubt if he knew there was a second half. When the distance from the nearest  NEC approved grounding connection, for the CATV coax cable grounding block, is greater  than 20ft then a ground rod at least 5/8" x 8 ft or a galvanized pipe minimum of 3/4" x 8 ft shall be driven in the earth near the grounding block. A copper ground wire no smaller than #14 awg shall connect to the CATV ground block to the ground rod or pipe by an approved clamp. 

Here is the rest, the part the installer missed. The ground rod or pipe shall connect to the main grounding system of the main electrical service by a copper wire minimum wire size #6 awg. An approved clamp shall be used to connect the #6 awg copper wire to the ground  Rod or pipe.

You have stated the main electrical service is on the opposite end of the house, 80 ft.
NEC says the ground wire shall be run in a straight short as possible run.

NEC says you can connect to a metallic incoming potable water line within the first 5 ft where it enters the building. Any chance your water line is metallic and enters at the front of the house and is accessible to run a #6 awg copper wire to?

**Note: If the incoming potable water line meets code as a grounding electrode you will see a water pipe ground clamp with a wire connected to the clamp. The wire will be at least a #6 awg copper wire. The wire goes all the way back to the electrical service and is connected to the main electrical service  neutral conductor.

If you were confident with the electrician you hired to install the 2) 120V dedicated circuits then I would recommend you hire him to install the proper grounding for the CATV coax cable grounding block. He will know what local codes are in your area. He will also be able to see the job first hand.  Proper grounding of the CATV grounding block is critical for lightning protection. What you have now could cause more harm than good.

Why he is there have him check, clean, and tighten all connections of the grounding electrode system for the main electrical service.

Also have him check the GFI receptacles on the lower lever.

The Jensen coax transformer will more than likely stop your ground loop hum problem. It will not protect your A/V equipment from a nearby lighting strike.   

Show this Link to your electrian

 http://ecmweb.com/code-basics/article-820-community-antenna-tv-and-radio-distribution-systems

Jim

Speedskater

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Now this is the important part:

Here is the rest, the part the installer missed. The ground rod or pipe shall connect to the main grounding system of the main electrical service by a copper wire minimum wire size #6 awg. An approved clamp shall be used to connect the #6 awg copper wire to the ground  Rod or pipe.

From our point of view (audio system) the ground rod construction matters not.
The ground rod is only there for thunderstorms and the such.

Folsom

Now this is the important part:

Here is the rest, the part the installer missed. The ground rod or pipe shall connect to the main grounding system of the main electrical service by a copper wire minimum wire size #6 awg. An approved clamp shall be used to connect the #6 awg copper wire to the ground  Rod or pipe.

From our point of view (audio system) the ground rod construction matters not.
The ground rod is only there for thunderstorms and the such.

That depends. If source impedance shifts then the grounding rod does have an affect all of a sudden. This gets worse when your equipment is referencing through ground from one to neutral on another. In fact if these problems are anything but that I'd be interested to know. SURE you can try to quiet the lines to make it good, but it's better to force the referencing between the IC's. You'll pickup a lot less RF that way, too.

Speedskater

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Once again - the ground rod has nothing to do with audio system quality.

The ground rod is only important during thunderstorms and big power company problems.

Speedskater

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Now in the older parts of the city with metal water pipes from house, a house with a "lost Neutral" problem may use a neighbor's water pipe to get it's Neutral current back to the power companies Neutral.

jneutron

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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. 

STOP.  Go no further.

Fix that first and foremost.

Cable MUST enter the building at the same location as the power.  When that is done and it's all bonded properly, see if you still have a problem.

jn

jea48

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STOP.  Go no further.

Fix that first and foremost.

Cable MUST enter the building at the same location as the power.  When that is done and it's all bonded properly, see if you still have a problem.

jn

jneutron,

That would be great if he can get the CATV company to relocate their coax cable to the back of the house.  Maybe a few pretty please might get the job done. The Op will catch more flies with honey than vinegar.

As for what is required per NEC code 2011 Article 820, NEC does not require the cable company to install the coax cable grounding block near the service entrance power. 

It is possible the local AHJ may require it.   

If I understand the OPs situation the utility power is located on the back of the property behind the house.

The CATV Cable Company's trunk, above ground or underground, is located in the front of the house property line, or easement.

http://ecmweb.com/code-basics/article-820-community-antenna-tv-and-radio-distribution-systems

For our discussion here the 2011 NEC Code, for the grounding of the CATV coax cable shield, is the same for the Link provided above. I have not read the 2014 NEC as yet.
   Jim

Speedskater

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NEC 2014 does not appear to have changed Article 820 Grounding Methods.
This is a short excerpt.  It's very long article and hard to puzzle out.

IV. Grounding Methods
820.100 Cable Bonding and Grounding. The shield of
the coaxial cable shall be bonded or grounded as specified
in 820.100(A) through (D).

(2) In Buildings or Structures with Grounding Means.
If the building or structure served has no intersystem bonding
termination, the bonding conductor or grounding electrode
conductor shall be connected to the nearest accessible
location on one of the following:
(1) The building or structure grounding electrode system
as covered in 250.50
(2) The grounded interior metal water piping system,
within 1.5 m (5 ft) from its point of entrance to the
building, as covered in 250.52
(3) The power service accessible means external to enclosures
as covered in 250.94 [ROP 16–185]
(4) The nonflexible metallic power service raceway
(5) The service equipment enclosure
(6) The grounding electrode conductor or the grounding
electrode conductor metal enclosure of the power service,
or
(7) The grounding electrode conductor or the grounding
electrode of a building or structure disconnecting
means that is connected to an electrode as covered in
250.32
A bonding device intended to provide a termination
point for the bonding conductor (intersystem bonding) shall
not interfere with the opening of an equipment enclosure. A
bonding device shall be mounted on non-removable parts.
A bonding device shall not be mounted on a door or cover
even if the door or cover is nonremovable. [ROP 16–186]

Cheeseboy

You guys are the best.

In the front of the house there is the main water input for the home.  The water goes from metal from the curb to plastic going into the house.  I would bet that the water pipes inside the house walls are metal.  Questions:

Can I connect my cable ground to the metal water pipes coming off the curb?

If I go into the wall and find metal water pipes can I connect my ground inside a wall?  or does the plastic original connection to the curb pipes defeat the ground.

I could send my girlfriend with cookies and coffee to say pretty please to the cable guys.  They would have to run from the street to the back of the house then back to the front again. 

What do you think

Speedskater

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For connecting to the dirt - how long do you think the metal part of the water pipe outside your house is?
Is that same water pipe inside the house connected at the service entrance to the main breaker panel?

jea48

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You guys are the best.

In the front of the house there is the main water input for the home.  The water goes from metal from the curb to plastic going into the house.  I would bet that the water pipes inside the house walls are metal.  Questions:

Can I connect my cable ground to the metal water pipes coming off the curb?

If I go into the wall and find metal water pipes can I connect my ground inside a wall?  or does the plastic original connection to the curb pipes defeat the ground.

I could send my girlfriend with cookies and coffee to say pretty please to the cable guys.  They would have to run from the street to the back of the house then back to the front again. 

What do you think

The water goes from metal from the curb to plastic going into the house.

Nope that won't work. At least 20ft of horizontal metallic pipe buried in the earth is needed. And it could only be used then if the water line was used as a grounding electrode for the main electrical service grounding electrode system.
You can forget the water pipe.....

If I go into the wall and find metal water pipes can I connect my ground inside a wall?

Nope,  for the reason as my response above.

I could send my girlfriend with cookies and coffee to say pretty please to the cable guys.  They would have to run from the street to the back of the house then back to the front again.

Homemade chocolate chip cookies?   :D

You do have a leverage advantage when dealing with the Cable Company. Their install does not meet bare minimum NEC code and I would bet therefore is a code violation of your local city electrical inspection department code.

The Cable Company has to do what is necessary to meet NEC Code.

Option....
Is the basement ceiling finished? Could a #4 copper ground wire be ran from the front of the house to the back of the house where the main electrical panel is located?

If it is possible the "Bonding Jumper Wire", fancy name for ground wire, could be installed from the ground pipe in front of the house through the basement fastened to the bottom of the floor joists, or ran through bored holes in the joists, to the grounding electrode wire that goes from the electrical panel to the outside ground rod/s. That would meet NEC Code.

Note I said a #4 awg copper wire instead of a #6. Code is bare minimum. I would increase the wire to #4 because of the distance. I would use #4 bare solid copper wire.

You would need to verify the driven pipe in the front yard is indeed 8 ft deep in the earth.  Also it is at 3/4" galvanized or plated corrosion  resistant pipe.

The Cable Company installer would never be able to handle the job. The Cable Company would have to hire a Licensed electrician.  The electrician may elect to drive a new 5/8” x 8ft ground rod in the front yard and not use the existing pipe.

The electrician will also know if running the Bonding Jumper Wire through the house meets your local electrical inspection dept code.  I do not see a problem With NEC Code.

Will you still need to use the Jensen ISO transformer? Don't know. But you already have bought it and it is on its way.

« Last Edit: 8 Jan 2014, 04:13 am by jea48 »

Cheeseboy

Progress is being made. 

The Cable Company has agreed to wire the ground as per code for thier cable box and will be at the house at 8 am on weds to do that. 

The Jensen ISO Transformer is in place.  Ta Da!  No hum on the TV.  No Hum in the stereo.  No transformer hum out of the cable box. 
The System sounds great.  I have had a hard time getting quiet time in the house to do a critical listen.  I like what I hear with the refridgerator, clocks, hairdryers, dogs and the other tv playing down the hall.  Can everybody just leave me alone for a half an hour please? 

I guess not. 

I have my electrician coming over for a visit.  We have much to discuss. 

What do you all think about Whole House Surge Protection?

SoCalWJS

 :beer:

Progress!  :thumb:

 :banana piano:



(now if only you could get some quality listening time.... :violin:)

Cheeseboy

Option....
Is the basement ceiling finished? Could a #4 copper ground wire be ran from the front of the house to the back of the house where the main electrical panel is located?

If it is possible the "Bonding Jumper Wire", fancy name for ground wire, could be installed from the ground pipe in front of the house through the basement fastened to the bottom of the floor joists, or ran through bored holes in the joists, to the grounding electrode wire that goes from the electrical panel to the outside ground rod/s. That would meet NEC Code.

Note I said a #4 awg copper wire instead of a #6. Code is bare minimum. I would increase the wire to #4 because of the distance. I would use #4 bare solid copper wire.

You would need to verify the driven pipe in the front yard is indeed 8 ft deep in the earth.  Also it is at 3/4" galvanized or plated corrosion  resistant pipe.

The Cable Company installer would never be able to handle the job. The Cable Company would have to hire a Licensed electrician.  The electrician may elect to drive a new 5/8” x 8ft ground rod in the front yard and not use the existing pipe.

The electrician will also know if running the Bonding Jumper Wire through the house meets your local electrical inspection dept code.  I do not see a problem With NEC Code.

Will you still need to use the Jensen ISO transformer? Don't know. But you already have bought it and it is on its way.

I requested the appropriate wire size in my service request.  The wire can be run under my deck on the side of the house to the backyard where it will be a Bonding Jumper Wire.   I hope they do not have to have an electrician do the job.   They may have to come back another day. 

jea48

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I requested the appropriate wire size in my service request.  The wire can be run under my deck on the side of the house to the backyard where it will be a Bonding Jumper Wire.   I hope they do not have to have an electrician do the job.   They may have to come back another day.

The CATV cable installer must follow the bare minimum standards of NEC.
http://ecmweb.com/code-basics/article-820-community-antenna-tv-and-radio-distribution-systems
See figure #3 picture illustration.

Quote
In one- and two-family dwellings, limit the grounding conductor length to 20 feet unless such a limitation just isn't practicable. If you need more than a 20-foot length, then you also have to install a separate ground rod that's at least 8 feet long [820.100(A)(4) Ex.]. Bond the rod to the power grounding electrode system with a minimum 6 AWG conductor [820.100(D)] (Fig. 3). If you don't bond the rod to the main system, you create a difference of potential and a flashover hazard.

If you run the grounding conductor in a metal raceway, bond each end to the raceway. This, like bonding that electrode, eliminates differences of potential.

The grounding conductor must terminate to the nearest accessible point or item from the list below:

•Grounding electrode system [250.50].

•Accessible service bonding means [250.94].

•Metallic service raceway.

•Service equipment enclosure.

•Grounding electrode conductor or associated metal enclosure.

•The grounding electrode conductor or grounding electrode of a building disconnecting means that is grounded per 250.32.
[/b


Here is another Link.
http://freenec.com/T632.html


Cheeseboy

The Cable Guy moved everything to the back of the house and life is good.  He just ran longer lengths of RF cable to the back then back to the front. 

I took the Jensen Cable transformer off the line.  No Hum.    I think I'll just put it back on the line and leave it there.

Any objections?

doctorcilantro

The Cable Guy moved everything to the back of the house and life is good.  He just ran longer lengths of RF cable to the back then back to the front. 

I took the Jensen Cable transformer off the line.  No Hum.    I think I'll just put it back on the line and leave it there.

Any objections?

Sorry if I missed this but is this an RCA based ISO or is a coax one that goes in-line? I have one of those that really worked very well. However, I don't seem to need it now that my Cable>TV>HDMI>COMPUTER chain gets isolated from HiFi at USB with an Adnaco S3B.

Cheeseboy

This is the coax based ISO unit from Jensen. 

jneutron

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The Cable Guy moved everything to the back of the house and life is good.  He just ran longer lengths of RF cable to the back then back to the front. 

I took the Jensen Cable transformer off the line.  No Hum.    I think I'll just put it back on the line and leave it there.

Any objections?

Yes.

We're not through here, not by a longshot... :nono:


What the heck was the 3 minutes off/30 seconds on thing???? :scratch:

I gotta know...didja fire 5 bullets, or 6??

jn