An electric shock from a hair dryer could be due to static electricity, a damaged lead, a damaged plug or moisture inside the hair dryer. This post aims to discuss 4 possible reasons why this is happening.
How Does An Electric Shock Occur?
An electric shock is a potentially dangerous situation which occurs when contact is made between an electrically live surface and earth.
This can occur from directly touching a live wire or indirectly touching a conductive material which has been energized due to an electrical fault.
When this happens, current travels from the voltage source then through the body and along skin to reach earth.
Earth is where you are standing in most cases, but it could also be a structure or appliance which has been bonded to the home’s earthing system. An example of this would be a steel kitchen bench which would need to be bonded to earth.
Electric shocks vary in intensity ranging from a small zap to fatal. The key things which determine the intensity of an electric shock are the amount of current and the time exposed to the current.
As both of these increase, the intensity of the shock increases.
Relatively little current is needed to cause severe harm (measured in milliamps, or a thousandth of an amp).
To protect against electric shocks, residual current devices (RCDs) are needed in the home to ensure that electricity to a circuit is cut off before severe harm or death occurs. For standard domestic situations, this is 30 milliamps of current within 300 milliseconds.
RCDs are required for most circuits in the home. This includes all lighting and wall sockets.
For wet areas where a hair dryer might be used, power circuits must be on an RCD.
Wall sockets that a hair dryer is plugged into must also be located a certain distance away from bathroom sinks, showers, baths and toilets.
For RCDs to work effectively, there must be a good earthing system in place. This means that appliances and conductive surfaces are bonded to the home’s earthing system.
Is A Hair Dryer Bonded To Earth?
A hair dryer might not be bonded to the home’s earthing system because it is a class 2 appliance. A class 2 appliance has a second layer of insulation in addition to basic insulation to protect users from making contact with any live parts.
Hair Dryer Fault Finding
A hair dryer is plugged into a wall socket which is protected at the switchboard by an RCD and a circuit breaker (typically 16A or 20A). Older homes probably won’t have RCD protection and instead have plug in fuses for protecting against short circuits.
Electric Shock From Hair Dryer? – Reason #1
Static Electricity
Likelihood: High – hair dryers also tend to lower humidity which increases the likelihood of static electricity.
Static electricity is generated in low humidity environments. Charged electrons build up on the surface of clothes, hair and skin before getting discharged by touching an earthed surface. As the voltages generated from static electricity can be so high, it is possible that you can hear and see the ‘electric zap’ or arc when it happens.
Electric Shock From Hair Dryer? – Reason #2
Damaged Cable
Likelihood: Moderate – if the hair dryer is old or not looked after.
Before checking the cable of the hair dryer make sure that it is unplugged.
A damaged cable will have broken insulation exposing copper wire strands. These wire strands can give someone an electric shock either by touching them directly or touching a wet or conductive surface the damaged cable is touching.
Electric Shock From Hair Dryer? – Reason #3
Moisture Inside Hair Dryer
Likelihood: Moderate – if in the bathroom.
Moisture inside the hair dryer can occur. This is especially true in a bathroom around sinks and hot tubs that can splash water. As tap water is conductive, it can allow electricity to travel increasing the risk of receiving a shock.
Electric Shock From Hair Dryer? – Reason #4
Damaged Plug
Likelihood: Moderate – if the dryer is old and not looked after.
A damaged plug exposing live wires or plug pins could potentially be a cause. Moisture in the bathroom increases the risk of shock even more.
Electricians Perspective
Static electricity is the most likely cause of a shock from a hair dryer. A shock is also likely if the hair dryer plug or cord looks damaged in any way or water has gotten into the appliance.
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