New Dedicated Line - Almost No improvement


Hello,

Newbie here and electrical idiot. Just moved to a new to us house in Tampa. Before we moved in I had an electrician put in a dedicated line (has it's own breaker switch) which is 10 gauge and two Furutech GTX-D outlets - Rhodium.

When I hooked up the EMI meter in my old house, which didn't have a dedicated line, the reading was usually around 26 or so IIRC. At the new house the outlets are 89 usually and the dedicated line is usually around 82 - so not much help for the cost of the "project" and pretty noisy.

Also, when the ac /hvac is running the meter reads about 100 points higher (!) for both the regular outlets and the dedicated Furutechs. Not good.

Thoughts? Does the dedicated line need it's own breaker box? 

I'm also considering a line conditioner but wanted to see what could be done here. Thanks.

laynes

I recently had my service replaced. A solid copper rod was driven about 5 ft deep into the ground outside. This was wired to the buss bars in the panel for my house. I have seen grids buried in the ground as well. The rod that was driven into the ground is a standard installation by code.

I recently had my service replaced. A solid copper rod was driven about 5 ft deep into the ground outside.

5/8" x 8ft is the minimum per code.

Driven Grounding Electrodes: Understanding what they are ...

 

If you say you have a dedicated line and are getting noise from the AC then you dont have a true dedicated line. A true dedicated has to be brought in independent from the street. At the very least you are sharing a ground on your dedicated line.

A true dedicated has to be brought in independent from the street.

Good luck getting that...

 

At the very least you are sharing a ground on your dedicated line.

Per code the EGC (Equipment Grounding Conductor) of a branch circuit shall be ran in the same conduit or cable and connect the equipment ground bus in the same panel the branch circuit originates.

Exception, when a branch circuit is fed from a subpanel where an isolated ground receptacle is used an insulated isolated ground EGC can be extended and connected to the main electrical panel equipment ground bus.

No dedicated isolated ground electrodes allowed... They serve no purpose and can be electrically dangerous to life.

An Auxiliary ground rod is acceptable per NEC provided it is connected to the EGC of the branch circuit wiring. (NEC 250.54)

.

From Bill Whitlock,  (https://www.prosoundweb.com/author/bill-whitlock/)

 

"In reality, most of the reports of fantastic noise reduction attributed to earth ground rods are actually the result of the separation of various ground wires and their connection to a single point. It is the separation of the ground current paths that eliminates the common-impedance coupling of noise from noisy equipment into quiet equipment. It is extremely rare for an additional earth ground connection to solve a noise problem."

Fact!
Mother earth does not possess some magical mystical power that sucks nasties from an audio system.


Grounding Myths

"Electromagnetic Compatibility Engineering" by Henry Ott

3.1.7 Grounding Myths

More myths exist relating to the field of grounding than any other area of electrical engineering. The more common of these are as follows:

1. The earth is a low-impedance path for ground current. False, the impedance of the earth is orders of magnitude greater than the impedance of a copper conductor.

2. The earth is an equipotential. False, this is clearly not true by the result of (1 above).

3. The impedance of a conductor is determined by its resistance. False, what happened to the concept of inductive reactance?

4. To operate with low noise, a circuit or system must be connected to an earth ground. False, because airplanes, satellites, cars and battery powered laptop computers all operate fine without a ground connection. As a mater of fact, an earth ground is more likely to be the cause of noise problem. More electronic system noise problems are resolved by removing (or isolating) a circuit from earth ground than by connecting it to earth ground.

5. To reduce noise, an electronic system should be connected to a separate “quiet ground” by using a separate, isolated ground rod. False, in addition to being untrue, this approach is dangerous and violates the requirements of the NEC (electrical code/rules).

6. An earth ground is unidirectional, with current only flowing into the ground. False, because current must flow in loops, any current that flows into the ground must also flow out of the ground somewhere else.

7. An isolated AC power receptacle is not grounded. False, the term “isolated” refers only to the method by which a receptacle is grounded, not if it is grounded.

8. A system designer can name ground conductors by the type of the current that they should carry (i.e., signal, power, lightning, digital, analog, quiet, noisy, etc.), and the electrons will comply and only flow in the appropriately designated conductors. Obviously false."

Henry W. Ott