This is definitely an issue and not a non-issue. While 1-2 amps might seem small, it's enough to be a significant shock hazard, and more importantly, indicates stray current that can cause accelerated corrosion of the gas pipes leading to leaks and potentially explosions. The sparking observed when the pipe was disconnected confirms the presence of a voltage difference. Here's a breakdown of how to approach this issue

Safety First!
Do NOT assume it's safe. Treat this as a serious electrical hazard until proven otherwise. Ensure everyone working on or near the gas lines is informed of the potential danger. Turn off the gas to the affected unit (and potentially adjacent units) immediately. Better safe than sorry. Contact the gas company, they are usually very responsive to calls like this.

Troubleshooting Steps


Grounding Assessment

The jumper cable could have temporarily bonded the system and reduced the spark, but it doesn't solve the underlying problem. The gas pipes are likely not properly grounded, or the grounding system has a fault. Verify the gas service entrance (where the gas line enters the building) has a proper grounding electrode conductor (GEC) connected. This should typically be bonded to the main electrical panel's grounding busbar. Check the integrity of this connection.2.

Electrical Isolation

Systematically try to isolate the source of the current.

Turn off the main breaker to the affected unit. Measure the current on the gas pipe again. If the current drops to zero (or close to it), the problem is likely within that unit. If the current doesn't drop

turn off the main breaker for the entire building, if the current goes away then the issue is most likely an appliance within the building.

If turning off the main breaker on the entire building doesn't work, look for possible stray current from a neighboring building.3. Current Tracing within the Unit (If the Problem is Isolated to a Unit)

With the unit's main breaker off, systematically turn on breakers one at a time and measure the current on the gas pipe after each breaker is turned on. This helps identify which circuit is leaking current to ground. Once a circuit is identified, check the following:

Appliances

Disconnect appliances one by one (e.g., water heater, furnace, stove, refrigerator). Measure the current on the gas pipe after each disconnection. Pay special attention to appliances with heating elements (water heaters, ovens, etc.) as they are often the source of ground faults. A clamp meter is ideal for this.

Wiring

Check wiring for insulation damage, especially where it comes into contact with grounded metal objects. Look for signs of rodent damage, water damage, or general deterioration.

Outlets and Switches

Inspect outlets and switches for loose connections, corrosion, or damaged wiring. Use a non-contact voltage tester to check for voltage on the gas pipe near outlets and switches.4.

Neutral-Ground Fault

A common cause of stray current is a neutral-ground fault. This occurs when the neutral conductor accidentally comes into contact with a grounded object. The gas pipe can become part of the unintended path for neutral current to return to the source (transformer).

Test for voltage between the neutral and ground conductors at the main electrical panel and at branch circuits. Ideally, this voltage should be very close to zero. A significant voltage indicates a neutral-ground fault somewhere in the system. Check for shared neutrals

Older wiring sometimes shares neutral conductors between multiple circuits, which can increase the risk of neutral-ground faults.5.

External Sources

If the above steps don't identify the problem, consider external sources of stray current:

Underground Utilities

Nearby underground power lines, telephone lines, or even street lighting systems can leak current into the ground, which can then find its way into metallic pipes. Contact the utility companies to investigate.

DC Traction Systems

If the building is near a train or trolley system that uses DC power, stray DC currents can be a significant problem. Contact the transit authority.6.

Corrosion Inspection

Even after the stray current is eliminated, inspect the gas pipes for signs of corrosion, especially near joints and connections. Replace any corroded sections.7.

Professional Help is Required

This is not a DIY project once you confirm the presence of stray current. You must involve qualified professionals:

Licensed Electrician

A licensed electrician with experience in troubleshooting electrical systems and grounding is essential.

Licensed Plumber/Gas Fitter

A licensed plumber or gas fitter should inspect and repair any gas pipe damage.

Gas Company

Notify the gas company immediately to investigate the possible current on the pipe.

Tools You'll Need



Clamp Meter (AC and DC if you suspect a DC source)

Essential for measuring current on the gas pipe without disconnecting it.

Multimeter

For measuring voltage, continuity, and resistance.

Non-Contact Voltage Tester

For quickly checking for the presence of voltage without touching wires.

Ground Resistance Tester (Optional)

For measuring the resistance of the grounding system.

Visual Inspection Tools

Flashlight, inspection mirror.

Important Considerations



Document Everything

Keep detailed records of all measurements, observations, and actions taken. This will be invaluable for the electrician and plumber.

Local Codes

Ensure all repairs and modifications comply with local electrical and plumbing codes.

Do Not Attempt Repairs You Are Not Qualified To Perform. Electrical and gas work can be dangerous if not done correctly.In summary, the presence of current on a gas pipe is a serious safety concern that needs immediate attention. Follow the troubleshooting steps, involve qualified professionals, and prioritize safety above all else. Do not proceed with any further work on the gas lines until the issue is resolved. Flag for review