Earthing or grounding is the transfer of electrical discharge to the ground by connecting part of a circuit or an appliance directly to the ground.
Washing machines must be earthed or grounded to protect it from excess electrical discharges that can cause shock to humans or damage to the washer’s electrical component.
Electrical earthing or grounding is as old as electricity itself. The earth cable protects a circuit or appliance by carrying excess discharge, from power surge, short circuit or lightening and directing it as neutral energy to the ground (mother earth).
What happens if you don’t ground a washing machine?
From a layman point of view, earthing does to any appliance or a circuit, or in this case our washing machine, what a drainage system does to a house or city.
Without the drainage, excess water generated from household and industrial activities are safely channeled to a city’s canal to prevent a house being flooded by waste water.
Also, in the event of rainfall or even a storm the city’s drainage carries excess flood water to a canal or even back to rivers and oceans.
Imagine what life would have been without a drainage. While not carrying drinking water, a good drainage is as important as a city’s water supply system.
This is how important earthing is to electrical appliances. Though not carrying energy producing current, with a proper channel to discharge excess current, electrical appliances will soon be overwhelmed and destroyed by sudden spike in current caused by external factors like thunderstorm and lightening.
How earthing is done
Let’s simplify the process of how electric energy is sent from a power source to our homes.
Understanding this will help to see the role ground plays in the whole setup.
First, to have electric energy, there must be:
- A power source
- A destination.
The source in this instance is a city’s power grid, or a transformer. While the destination is our homes.
Without delving deep into electricity, every household electrical system has a wire carrying positive electrical energy from a city’s gride to the house. This wire is usually colored red (international color standard).
A second wire carries neutral energy from the house back to the city’s gride. This is usually colored black.
The table below shows all internationally accepted power code for the different electric source.
|Cable Combination||Live (positive)||Neutral (negative)||Earth (ground)|
|Red Black Yellow||Red||Black||Yellow|
|Red Black Black||Red||Black||Brown|
|Red Black Yellow-and-White||Red||Black||Yellow-and-White|
|Red Black Green||Red||Black||Green|
As a generally rule, if there is, Red, Black and a third color in any cable, the third color is the ground.
In a 2-wire cable with only black and white, Black is the live and white is Neutral. There is no ground.
When the move of positive energy (life) to the house forms a loop with the negative energy (neutral) from the house back to the city’s gride completes a loop, electrical power is generated in the destination (individual homes.)
However a third wire is also connected to the set-up. The work of this third wire is to protect the function of the energy flow (to and from) of the positive and neutral cables from external electric energy.
In an AC circuit, that is the types used by power grids, and generators, (anything that is not battery power DC), the positive and negative power sources are referred to as Live and Neutral respectively. But for simplicity, we’ll keep referring to them as positive and negative.
Electrical energy is constantly generated in the atmosphere:
- Static energy from dry air, and dust
- Thunder and lightening
The electrical energy are often extremely large for human consumption. When they interfer with the flow of domestic electric energy in households, they destroy any appliance in their parts
You can compare energy from electrical energy used in houses to air from Air Conditions, and that produced by lightening as a hurricane or other storms. When both meet, only one suffers, your AC.
The function of the third wire is to create a safe part for these external energy.
It attracts this energy, acts as a corridor and sends it to a rod dug into the ground. This rod sends the electrical energy to the ground or the earth.
That is why it is called Earth or Ground.
This is an over-simplified (and probably incomplete) explanation of what how earthing works.
For an indepth explanation on earth system, please read this wikipedia article
The relationship of household electric power to those from lightening can be compared to water in kitchen faucet and flood water from a rainstorm. If both crosses paths, the entire house and all plumbing facility suffer. To prevent this a drainage is needed to channel flood water away from house plumbings.
How washing machine’s earth works
All metal surface and electronic circuit boards are potential grounding point for induced current from lightening.
But the metal casing of a washing machine is especially … because of its wide surface area.
For a washing to benefit from the electrical protection given by the house wiring’s, it must be connected to the ground of the house.
Where to connect ground wire washing machine?
A three-pin power plug is used to connect earth wall socket.
The third cable of the plug connects to the earth in the socket.
In the rare event that a washing machine’s power cord has only two wires, a live and a neutral, an earth must be manually created.
A third wires is screwed, tired or soldered onto any metal part of the washer and connected to an already installed earthing system.
This system is then connected, either to a house’s earth wiring, or it is connected to one of the earth rods in the building.
Never connect a washing machine’s earth to a gas pipe, plastic water pipe or telephone line. This will result in electric shock, fire or an explosion.
Does a washing machine need a separate ground wire?
All washing machine come with three-pin plug. When connected to a wall socket with that is also connected to the house’s earthing system, a separate ground wire is not needed.
But in the even that the wall outlet does not have a third wired attached, (this is a litmus test, even if you know little about electrical wiring. An wire connection with only 2 wires, does not have an earth attached. The earth is always the third cable in a wiring.) you will need to connect a separate ground wire.
All operational washing machines must be connected to a ground system. For safety reasons, this is not an optional addition in a washing machine installation. It is a must.
If a wall socket does not have a ground wire, or the washing machine power cord does not have one, a separate ground wire must be connected using the standard color code for cabling and attached a the nearest ground wire or grounding system.
How to tell if your washer has a faulty or missing ground wire?
- Use of 2 wire power plug
- Shocks from washer’s outer casing.
Even cable must have a positive (live) and negative (Neutral) wire. These are cable one and two.
Without one of these two there’ll be no power supply to any unit.
The earth’s cable is the third in any cable.
If your washing machine has two cable (actually, I’ve never one with two cables), or the wiring of the wall socket only has two cables, then know that the earth or ground is missing.
This method of inspection, though, is highly limited. Because, For one thing, it relies on the assumption that the wiring is a surface wiring
For most structures built with conduit wiring, it is hard to see the cabling that supplies a wall socket.
Secondly, a bad wiring might have 3 cables, without the third being connected to the house’s ground or earth.
This is where the next technique comes in.
Shocks from washer’s outer casing
As a rule, a washing machine’s does not shock.
The only exception is when a live wire disconnects and touches the appliance’s outer.
This is a rear occurrence.
Oftentimes, a shocking washing body is the sign of a faulty or non-existing ground.
When this happens:
- Switch off your unit,
- Call an electrician
- Ensure there is no leakages from the washer or water from other source around it.
- Restrict access to the washer to minors
How to ground a washing machine
How to fix grounded washing machine
The ground wire is not needed for the operation of a washing machine. It can function without it.
However it is important for the safety of the appliance and any circuitry. But most importantly, for the safety of human life.