An electric shock from a dishwasher can happen for several reasons.
Static electricity build-up on clothes, wear and tear inside the dishwasher, water on electrically live parts, and a damaged lead or plug are all reasons why someone might get a shock.
This post aims to explore why someone might be getting a shock and what can be done about it.
Why Would Someone Get A Shock From A Dishwasher?
Before talking about what might have caused the electric shock let’s look at how an electric shock can happen.
Firstly, an electric shock occurs when physical contact is made between an electrically live surface, such as a wire or metal body and the ground (earth).
This can be someone physically touching a wire with their hand while having feet touching the ground. When this happens, a circuit is made between these two points causing electrical current to flow from the electricity source to earth.
The electrical current travels along the body’s skin and organs and this is what produces the electric shock sensation which can be very deadly.
Not all electric shocks are equal. There are a few factors which determine how severe an electric shock can be. Time exposed to an electric shock and amount of current both increase the severity of the shock.
If someone has a better ‘earth connection’ meaning they are not wearing insulated shoes and standing on moist ground, they can expect to get a much worse or even fatal electric shock.
If you get an electric shock from a dishwasher it is important to consider what footwear you are wearing. Insulated shoes could have prevented a much worse shock.
The severity of shocks is why residual current devices (RCD’s) exist – to protect people should an electrical fault occur.
Interestingly, an RCD is designed to trip and shut off power within 300 milliseconds at 30 milliamps of shock current which will protect most people from significant harm. This ‘threshold’ is laid out in the IEC Shock Limits graph.
For an RCD to work there needs to be good earthing in place. The earthing system prevents hazardous voltages from appearing on conductive parts of the dishwasher. A dishwasher will be bonded to the home’s earthing system via the wall socket it is plugged into.
Now that we have some background information on what exactly is an electric shock, let’s look at what might be causing it.
Dishwasher Fault Finding
As a safety warning, always unplug the dishwasher from the wall socket before attempting to do any fault finding.
A dishwasher will typically be plugged into a wall socket via a power cord. This wall socket should be protected by a circuit breaker at the switchboard. This may or may not be located at the main switchboard. There may be other sockets and appliances on the same circuit.
If the dishwasher is plugged into a wall socket it is most likely protected by a 16A or 20A MCB and an RCD.
Before going any further, it is a good idea to check whether a breaker has tripped in the main switchboard. If a tripped breaker is related to the dishwasher it might be labelled ‘power’ or ‘dishwasher’.
A tripped RCD will indicate that there is an electric shock hazard and current is leaking to earth.
Electric Shock From Dishwasher? – Reason #1
Static Electricity
Likelihood: High – especially in low humidity.
Static electricity is the result of friction causing electrical charge to build up on clothing, hair, shoes. You may not know that an electrical charge has built up until you make contact with a metal surface (such as the body of the dishwasher) resulting in an electric shock.
A static shock is mostly harmless, although unpleasant.
A static shock can be reduced by having a mat near the dishwasher (a mat will help discharge the static) and ensuring that the room maintains some humidity.
Electric Shock From Dishwasher? – Reason #2
Water On Live Contacts
Likelihood: Low – Moderate – if the dishwasher hasn’t been well maintained.
Dishwashers operate with water. If water has leaked, sprayed or flooded onto electrically live parts, it could increase the risk of getting a shock.
It is a good idea to check if any flooding or water damage behind and around the dishwasher is present. Water could have even gotten into the wall socket or plug.
Electric Shock From Dishwasher? – Reason #3
Damaged Lead Or Plug Touching Frame
Likelihood: Moderate – unless rodents have been present
If the insulation on the power cord is damaged, then exposed wires can potentially cause an electric shock.
The insulation on a cable can become damaged due to rodents present behind the dishwasher and squashing/crushing of the cord resulting in exposed (live) wire strands.
Investigating the cord is a good step to finding out why someone might get a shock from a dishwasher.
Electric Shock From Dishwasher? – Reason #4
Wear And Tear Inside Dishwasher Exposing Live Wires
Likelihood: Low
A dishwasher, if poorly maintained and used against manufacturers instructions, could give someone an electric shock. This is mainly due to loose and exposed wires touching metal parts of the dishwasher. When someone touches this they will get a shock.
Electricians Perspective
Static electricity is the most likely reason that someone might get a shock from a dishwasher. However, if there is evidence of flooding near the dishwasher, damage to the power cord or wear and tear of the dishwasher then these could be valid causes as well.
We Fix Faults is an electrician blog dedicated to finding and fixing common domestic faults.