Is High Voltage Low Current Electricity Dangerous?

The electrical circuits that power your home are a modern staple. All of your lights, appliances and air conditioners run off a relatively safe electrical system that supplies 240 Volts to your wall sockets. Getting that power into your house is the real challenge. Most of the electricity that gets transmitted around our suburbs travels at much higher voltages outside the home, with circuits ranging from 132kV (132,000 Volts) to 275kV. That’s a big jump from your household power supply, but that power is transmitted at relatively low currents. Low current transmission means that large amounts of electricity can be transported more safely and efficiently.

You may have heard the old saying that it’s not the voltage that kills, it’s the current (amperes). If that’s the case, then you may be wondering whether high voltage circuits are actually dangerous or not.

Why is Electricity Dangerous?

To discover why electricity is dangerous to humans, we need to understand how electricity works. At its most basic level, electricity is an expression of energy. If electricity flows through your body, the energy it carries is released in the form of light, heat and sound. In most cases, electricity that passes through your body will heat up the tissue around it and cause internal burns. Depending on how much electricity flows through you, the effects can range from totally harmless to severe burning, organ failure and even death.

Before electricity can be dangerous to a person, it needs sufficient Voltage and Amperage to pass through the body and do damage. It’s the combination of both of these things that result in energy that’s capable of harming you. For instance, common static electricity can be in excess of 30,000 Volts, but all you feel is a sharp zap. That’s because the amount of current in static electricity is incredibly low. On the other hand, if you receive an electric shock from one of the 240V circuits around your home, the current of 10-15 Amps means the electricity could be enough to do serious harm.

How Much Current is in High Voltage Systems?

Since we know that we need the combination of voltage and current to do harm, does that mean high voltage power supplies operating at low currents are harmless? 

The large steel towers you often see carrying power are part of Australia’s high voltage electricity system. The smaller towers carry power at 132kV, while the larger ones carry power up to 275kV. Since power is often produced at plants far away from our population centres, it needs to be transported long distances. This is done at high voltage and low current to make the process cheaper and more efficient.

With that said, high voltage power lines often transmit up to 1000 Amps of current at any given time. That’s about 100 times more current than household systems carry, and about 12,000 times more current than is needed to injure or kill a human. While some electric shock victims are lucky and survive huge amounts of power, if the electricity passes through your heart, then as little as 0.08 Amps could be fatal.

How do Electricians Service High Voltage Systems?

So, if high voltage systems are so dangerous, how do electricians service them? The simple answer is to say that high voltage systems are always serviced while unpowered. The risk to people performing electrical work on live circuits is incredibly high, even when other safety precautions are in place. High voltage electricity is especially capable of “jumping” through the air and contacting someone who is working on the power lines, even when they are insulated from the ground and contactors. When working on unpowered high voltage systems, electricians will still take a range of safety precautions to keep themselves insulated and reduce the risk of an electric shock that could prove fatal.

Need High Voltage Electrical Work? Contact Asset Power Solutions

Working with high voltage electricity requires special care, not only to avoid the risk of injury, but also to protect the powered circuits from costly damage. The Asset Power Solutions team is certified to work on all high voltage systems up to 132kV. We take great care to ensure all work is carried out safely by licensed and trained electricians who can complete your job on time and within budget. Contact Asset Power Solutions today and talk to us about our high voltage electrical services.