This is a serious and potentially dangerous situation. Here's a breakdown of what's likely happening, why it's a problem, and what you should do

Understanding the Problem: Ground Loops and Current Flow
Grounding System Basics

Your electrical system has a grounding system designed to provide a low-resistance path for fault current in the event of a short circuit. This helps trip breakers and prevent electrical shock. Key components include:

Ground Rod(s)

Metal rods driven into the earth, providing a physical connection to the ground.

Grounding Electrode Conductor (GEC)

The wire connecting the ground rod(s) to your main electrical panel's grounding bus.

Equipment Grounding Conductors (EGCs)

The ground wires within your electrical circuits (the bare or green wires) that connect to outlets, appliances, and other equipment.

Ground Loops

A ground loop occurs when there are multiple paths to ground, creating the possibility of current flowing through the grounding system. This is not the intended design of the grounding system. The grounding system should only carry current during a fault.

Why is the Cable Ground Involved? Cable companies also ground their equipment (the cable TV box and associated hardware) to prevent signal interference and protect against power surges. They often bond their ground to your home's grounding system. Current Flow = A Problem

The fact that you're reading current on the cable company's ground wire when it's connected to your ground rod indicates that current is using it as part of an unintended path.

Possible Causes

Here are the most likely reasons for the current flow:1.

Neutral-Ground Fault

This is the most common culprit. Somewhere, a neutral wire (the white wire) is improperly connected to a ground wire or a grounded metal component. This can happen in several locations:

Inside your house

A miswired outlet, a faulty appliance, or improper wiring in a junction box.

At the electrical panel

Improper wiring of the neutral and ground bus bars. A loose neutral connection can cause this. THIS IS VERY DANGEROUS. Do not attempt to fix this yourself.



Outside the house

The utility company's neutral conductor might have a problem between the transformer and your service entrance.2.

Utility Neutral Issue

As mentioned above, the utility company's neutral might be compromised. If their neutral is weak or broken, current can find other paths back to the transformer, including through your home's grounding system and the cable company's ground.3.

Other Grounding Problems



Poor Grounding Rod Connection

The connection between your grounding electrode conductor (GEC) and the ground rod might be corroded or loose. This increases the resistance of your grounding system, causing current to seek alternate paths.

Multiple Ground Rods (Unequal Potential)

If you have multiple ground rods, and they're not properly bonded together, they could be at slightly different electrical potentials, leading to current flow between them.4.

Neighbor's Issue

In rare cases, a grounding problem in a neighboring house could be sending current through the shared ground.

Why This Is Dangerous



Electrical Shock Hazard

The grounding system is designed to protect you from shock. When it carries current under normal conditions, it can create a shock hazard if you touch grounded metal parts.

Fire Hazard

Excessive current flowing through the grounding system can heat up wires and connections, potentially leading to a fire.

Damage to Appliances

Stray current can damage sensitive electronic equipment.

Cable Interference

Current in the cable ground can cause interference and degraded cable TV or internet service.

Damage to Cable Equipment

Current in the ground can damage the cable company's equipment

What You MUST Do

1.

IMMEDIATELY CALL A QUALIFIED ELECTRICIAN. This is not a DIY project. Dealing with electrical problems without the proper knowledge and tools can be extremely dangerous, even fatal. Explain the situation clearly, emphasizing the current on the grounding wire and the voltage fluctuations. They will need to:

Inspect your entire electrical system

They'll trace the wiring, check for neutral-ground faults, and ensure all connections are tight and properly made.

Test the grounding system

They'll verify the integrity of the ground rod connection and the continuity of the grounding electrode conductor.

Use specialized equipment

Electricians have tools like ground fault locators to pinpoint the source of the current.2.

NOTIFY THE CABLE COMPANY. Inform them that you have a significant current on their ground wire and that you suspect a neutral-ground fault or other electrical problem. They might be able to help diagnose the issue, especially if it involves their equipment or grounding practices. They may need to disconnect their ground from your system until the problem is resolved.3.

DO NOT REMOVE THE CABLE COMPANY'S GROUND WIRE YOURSELF (permanently)

While removing it stops the current reading on that wire, it doesn't fix the underlying problem. It just removes a symptom. Removing the cable ground could leave their equipment ungrounded, potentially creating a hazard for cable technicians and causing interference. You may remove the cable for testing purposes only as you did in your first post.4.

BE CAREFUL

Avoid touching any exposed metal parts of electrical equipment, especially if you feel a tingle or shock.

Steps the Electrician Will Likely Take



Voltage Checks

Measure voltage between neutral and ground at various points in the system. Ideally, this voltage should be close to zero.

Continuity Testing

Check the continuity of ground wires to ensure they are properly connected.

Ground Resistance Measurement

Measure the resistance of the grounding system (the ground rod and its connection).

Isolating Circuits

Disconnect circuits one by one to see if the current flow stops. This can help pinpoint the circuit with the fault.

Appliance Testing

Check appliances for neutral-ground faults.

Important Considerations



Documentation

Keep detailed records of all work done by the electrician and the cable company.

Permits

Depending on your local regulations, electrical work might require a permit. Make sure the electrician obtains the necessary permits.

Safety First: Never attempt electrical work if you are not qualified and experienced. Your safety and the safety of your family are paramount.This is a serious electrical issue that requires professional attention. Don't delay in contacting a qualified electrician to diagnose and resolve the problem. Good luck! Flag for review