A washing machine doesn’t necessarily need to be on its own dedicated circuit.
However, a washing machine should be on a circuit that can handle its full operating current as well as the operating current of any other appliances on the same circuit.
This post will go into four things you should consider when wiring for a washing machine.
Washing Machine Wiring Overview
A washing machine is typically plugged into a wall socket.
This wall socket will be wired with a cable that leads back to the switchboard. In the switchboard, this cable will be terminated into circuit protection devices (breakers).
These breakers are designed to prevent damage or harm should an electrical fault occur with the cable or washing machine.
One type of electrical fault is called an overload. An overload occurs when too much current flows through a cable.
As a result, the cable heats up and may catch on fire if the breaker doesn’t trip to shut off power.
An overload can be caused by appliance such as an oven drawing large amounts of current. It can also be due to several appliances on the same circuit collectively drawing a large current. The result of an overload is the same.
Because overloads pose a fire risk it is important to install the correct sized cable for an appliance’s electricity demand.
Cables with a larger diameter are able to handle larger currents without heating up. An oven will be wired with a much larger cable than a light fitting.
Let’s look at four considerations you need to make before wiring for a washing machine.
1. Check Electrical Specs For The Washing Machine
Checking the specification sheet for the washing machine is vital to understanding whether the washing machine can be on a dedicated circuit or not.
The specification sheet is often found in the instruction manual but can be found online too. It will tend to have the following details:
- Operating voltage (when the voltage changes such as before an outage, the washing machine can get damaged.).
- Frequency.
- Operating current.
- Fuse rating.
The operating current is the most important piece of information. The operating current tells us how much current will go through the cable when it is in operation.
For washing machines this can vary. Modern washing machines implementing smart drives don’t use much power, while older washing machines can use a lot.
2. Consider Cable Size To Use
Standard power outlets are typically wired with 1.5mm2 or 2.5mm2 cable.
These cables should be protected by a breaker rated at 16 amps and 20 amps respectively.
This is the limit of current that can be drawn through the cable before the breaker trips on overload. The breaker trips to protect the cable.
The washing machine must draw less current than the cable and circuit breaker it is installed on – provided that other appliances are not on the same circuit. If not, a larger cable needs to be installed.
3. Consider Other Outlets And Appliances On Same Circuit
Consider other appliances which may be on the same circuit.
If the total current drawn by other appliances is greater than the cable & circuit breaker size, then you could trip the breaker.
The amount of time the washer runs per day is also important. If the washing machine is running non-stop it will use more power than if it is only used a few times per week.
Unlike a fridge, a washing machine is unlikely to be running 24/7 so this should be taken into consideration about whether or not several appliances will be operating at the same time.
If they are, it may be worth putting those appliances on their own circuit or maybe putting the washing machine on its own circuit.
4. Choose Circuit Breaker For Overload & Short Circuit Protection
A standard MCB will protect against both short circuits and overload. Ensuring that the right breaker is installed for the right cable is crucial.
If the breaker is rated too high (such as a 32A breaker on a 20A cable), then the cable will catch on fire in an overload.
Always aim for the breaker to be rated below the cable capacity.
As mentioned before, wall outlets are typically wired with 1.5mm2 or 2.5mm2 cable which has a 16A or 20A breaker respectively.
Electricians Perspective
A household washing machine doesn’t necessarily need a dedicated circuit unless the existing circuit it will use is overloaded. If there are too many other appliances using the same circuit at the same time as the washer it may be a good idea to install a dedicated circuit either for the washer or for those other appliances.
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