What Happens When You Touch an Electrical Busbar?

Electrical Technology

What Happens When a Person Comes into Contact with a Live Busbar?

Busbars in main panels and distribution boards are often fed by high voltage and current, for example, 7.2kV in the U.S. and 11kV in the U.K. and IEC-compliant countries. Touching a live busbar without standing on a rubber insulating mat or wearing rubber insulating gloves can result in immediate electrocution.

A busbar is simply a conductor that carries high voltage and current, so touching it has the same effect as touching any live conductor.

If you touch a busbar without making contact with any other wires (live, neutral, or ground) and without being in direct contact with the ground, for example, if you are hanging from a busbar like a person hanging from power lines, nothing would happen.

But if you touch the busbar while standing on the ground, it provides a path for the current to flow from the live conductor to the ground. In this situation, a line-to-ground (L-G) fault occurs. You would feel a powerful electric shock before the main breaker trips, and the current passing through you could easily be fatal.

Inside the busbar chamber of a breaker panel, if you are completely isolated (i.e., there is no conductive path to the ground) and touch the busbar with bare fingers, nothing will happen. However, in most cases, the consequences are severe, ranging from burns and severe electric shock to instant death.

If you touch a busbar that is grounded using a copper wire, you will experience a blinding flash, followed by a blue blotch in your vision and tiny bits of molten copper embedded in your glasses due to the vaporization of the conductor. The point of contact will typically leave a black burn mark.

To avoid the risk of instant death, never attempt to touch a live electrical busbar under any circumstances.

Consequences of Touching Electrical Busbars

Touching a busbar, which is a conductor that distributes electrical power within an electrical system, can result in serious injury or death due to electric shock or electrocution, depending on the voltage and current levels present.

Here’s what could happen:

Electric Shock: If the busbar is live and you touch it, current will flow through your body, potentially causing severe damage to your tissues, muscles, and organs. The severity of the shock depends on the busbar’s voltage, the duration of contact, and the path the current takes through your body. Even at lower voltages, shocks can be painful and dangerous.
Burns: Touching a high-current busbar could cause severe electrical burns, both internally and externally. During the incident, electrical energy is converted into heat within your tissues. These burns can be life-threatening, especially when the current flows through critical body parts such as the heart.
Arc Flash or Arc Blast: If the busbar is exposed and there’s a fault (like a short circuit), it can result in an arc flash. During this process, a plasma arc releases a massive amount of energy in the form of light, heat, and pressure. This can cause third-degree burns, damage to your eyesight, or even hearing loss from the explosive force.
Electrocution: If the voltage is high enough (above 50V AC or 120V DC), there is a significant risk of electrocution, where your heart rhythm could be disrupted, leading to cardiac arrest.

For safety, it’s essential to never touch a busbar unless it’s de-energized, properly grounded, and you are using the correct personal protective equipment (PPE), including insulated gloves and tools designed for electrical work. Always follow strict lockout/tagout (LOTO) procedures when working near busbars or any energized or de-energized electrical equipment.

Related Post: Will a Man Get an Electric Shock If He Hangs on a Live Wire?

Why You Should Never Make Contact with Busbars?

When a person comes into contact with a live busbar, and they are grounded or in contact with another conductive path, they become part of an electrical circuit. This allows electric current to pass through their body, which can lead to severe consequences, including electric shock, burns, and potentially instant death.

Busbars typically carry high voltages and currents. The human body offers resistance to the flow of electric current, which causes heat and damage to tissues. The current will flow from the live busbar, through the person, and into the ground or another conductive surface.

The severity of the injury or fatality depends on factors such as the voltage, current, duration of contact, and the person’s overall resistance. In most cases, the result is a powerful electric shock that can cause immediate electrocution before protective devices like circuit breakers have a chance to trip.

This is why never touching a live busbar or any live electrical conductor is critical for safety.

Main Lugs Are Similar to the Busbars

The main lug screws shown in the fig of 120V/240V panel are constantly energized, similar to live busbars.

Never ever touch the main lugs (terminal screws). These lugs are always HOT (live), regardless of whether the main switch in the panel is ON or OFF. They are only de-energized when the Main Disconnect Switch is OFF.

Caution

Always disconnect the main power supply before working on any circuit.
Never touch any electrical conductor or bare wire under any circumstances. Always consult a licensed electrician for electrical work.
Electricity is dangerous. Never take risks with it, as even a small mistake can cause serious harm.
Always follow safety precautions and protective measures to avoid and reduce electrical hazards.