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The Ultimate Guide to Electrical Safety for Homeowners

How to Prevent Electrocution in Your Home

The purpose of this guide is to inform my local community on electrical
safety in their home.
Follow the guide and use the images to help you identify whether your
switchboard is safe and meets current regulations.

Let’s dive right in.

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Home Owners Guide

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Quick Summary of Guide

1. Switchboards

Can your switchboard protect you from Fire and Electrocution?

Ceramic Fuses are the oldest form of protection and should be in a museum and not protecting your home! If you still have these you seriously need an upgrade.

Circuit breaker (MCB’s) – No ceramic fuses? Perhaps you have MCB’s. These are designed to trip off in an overload or short circuit to protect against fire but do not protect against fatal electrocution.

Old Safety Switches (RCD’s) are electrocution protection devices which are added to ceramic fuses or MCB’s to protect against electric shock. One RCD usually protects multiple circuits so one small fault in one circuit can result in loss of power to most of your house.

Modern Safety Switches (RCBO’s) electrocution protection devices which offer the best protection, fire and electrocution protection in one device and on top of that you have one per circuit so a fault in one circuit will not affect other circuits.

Quick safety test – Perform a quick test of your safety switches to

electrical safety - Safety switches

2. Earthing Your Home

Is your home safely earthed?

Electrical Earth Rod check you can see your earth rod, you should see the top of a long copper rod sticking out of the ground, usually  near or under your switchboard.

Earthing wires – If you cannot see an earth rod and instead you see wires connected to your water pipes then call your electrician as this form of earth may no longer be adequate to protect you and your
house in times of electrical fault.

Surge protection – are you using individual surge protector units? You may want to have a surge protector fitted to your switchboard instead so that everything in your house is protected.

3. Main Switch

Old main switches are infamous for burning out in an overload and have to be turned off manually, they are dangerous and need to be upgraded.

Asbestos back panels are common with older switchboards, check for the asbestos warning sticker or call an electrician.

Modern main switches trip automatically when they detect a dangerous current entering the switchboard protecting your home from a possible fire.

If your house is pre-1990’s ask an electrician to check if your mains cable and main switch is rated correctly for the electricity demands of your home.

1: Switchboards

In this chapter you will learn how to make sure that your switchboard  can protect you from Fire and Electrocution? Just keep reading! 

Can your switchboard protect you from Fire and Electrocution?

I’m starting this guide off with switchboards because all too often I come across old, unsafe switchboards in people’s homes.

I have over 10 years of experience as an electrician and trust me, electricity is not something to be messed with. Electricity is an invisible force that could potentially blow up equipment, or even worse, cause fatalities
if managed incorrectly.

A switchboard is your protective unit that takes power from the main grid and distributes it safely throughout your house.  

Switchboards have changed a lot over the years and for a very good reason – they make our homes a MUCH safer place to be.

Firstly, at the very least, a switchboard should protect our homes from an electrical fire. Some old switchboards I come across are not even able to do this.  

Secondly, with the development of safety switches, which are now a legal requirement, switchboards can protect us from electric shock.

Should you or your family come into contact with electricity the switchboard will shut down the supply of electricity within 0.3 of a second, preventing serious or fatal electrocution. In this day and age, you would expect to see this level of safety in all houses, however, this is sadly not  the case.

Read on to learn how to identify the type of switchboard you have and the steps you can take to improve Electrical safety in your home.

Does Your Switchboard Meet Current Safety Regulations?

Types of Switchboards:

1. Ceramic Fuses

These are the oldest type of switchboards around. They can help to prevent a fire but do not prevent electric shock.  In a ceramic switchboard, each circuit is protected by a fuse wire that is contained within a ceramic fuse carrier (see image 1.1). The fuse wire is rated to burn out should the circuit get too hot/be exposed to excessive current over its rating, usually caused by a short circuit or an overload (too many things trying to pull electricity on that cable).
The fuse wires are proportional to the cable they are protecting and will burn out/blow before the cable can catch on fire. For example, a ceramic fuse protecting an electrical circuit for lights (which uses a small cable) will have a smaller fuse wire than the ceramic fuse protecting a circuit for power points (which uses a larger cable).

Electrical Safety - Switchboard
Image 1.1: Example of a switchboard that is still using ceramic fuse protection (except the air conditioning circuit which is protected by a miniature circuit breaker or MCB). You can also clearly see the size difference between the electrical cables supplying the ceramic fuses, with the cable to the lights being the smallest (indicated by the single arrow) and the cable to the hot plates the biggest (indicated by the two arrows).

In General:

Light circuits

Light circuits use a 1mm or 1.5mm electrical cable and are protected by 8-10 Amp fuse wires.

Power point circuits

Power point circuits use a 2.5mm cable and are protected by 16 Amp or 20 Amp fuse wires.

Large appliance circuits

Circuits such as ovens and A/C units can use 4mm and 6mm cables which are protected by even more heavy-duty fuse wires of 25, 32 or 40 Amps.

Ceramic Fuses are Unsafe

The problem with ceramic fuses is that it is all too easy to use the wrong protection for the circuit. Over the years the ceramic fuse inserts can be
confused and crossed over. For example, when someone has an issue with the switchboard the fuses can get taken out and put back in the wrong place resulting in the fuses no longer being matched to their corresponding cables.

Electrical Safety - Ceramic Fuse
Image 1.2: Example of a ceramic fuse that has been re-wired with three strands instead of the one that is designed to burn out under a dangerous heat.
Let us look at Andrew’s story:

Andrew knows how to re-wire the old ceramic fuses in his switchboard and has a bunch of fuse wires stashed away for emergencies. His lights blow a fuse and he goes out to the board. He pulls several ceramic fuses out of their holders to see which one blew and re-wires it with a wire from his fuse wire stash. Unbeknown to him, he had put a heavy-duty fuse wire into the blown light circuit and then when putting all the fuses back into their holders he also accidentally put the oven circuit fuse, which is also a heavy-duty fuse wire, onto a smaller power point circuit.  Let’s now hope that Andrew doesn’t pull too much current (use lots of appliances at once) on his power circuit because now the protection will not work in time to stop a fire. Same goes for his lighting circuit, if he has  another overload the cable or lights may catch on fire before his switch- board operates.

Let’s look at Jim’s story:

Jim has been living in his house for over 50 years and knows everything about it like the back of his hand. He keeps a spare stash of fuse wires handy because every so often he has a tripping problem on an overloaded circuit ever since his son bought him a new washing machine for
Christmas. This time he finds he has run out of replacement fuse wires so
he goes into his garage to see what he can use instead. Aha! He finds a hairpin which looks about the same size as the fuse wire he has used in the past and gleefully wedges it in place inside the ceramic fuse carrier. He then goes inside to do another load of washing.
This was the last load of washing that Jim ever did in that house. Fortunately, his smoke alarm alerted him and his wife to get out in time before anyone was hurt but unfortunately not much of his home survived the fire.

I have seen it all, hairpins, bits of copper, multiple bits of wire, people that figured if it keeps popping on one, why not add three! (Image 1.2). I even saw a bent nail once which would have had no chance of blowing. In the event of a short circuit or overload, it would have been nail 1 – house 0.
Thankfully the installation of ceramic fuses was banned years ago, however, some homes are still using them and it is now up to homeowners and electricians to keep an eye out for them and get them upgraded.

If you do still have ceramics on your switchboard call an electrician and ask if they can do an electrical safety inspection. They can give it a good look over and this is a free service that a good customer safety-focused company will usually offer with any service.

Call us if you would like an electrical safety inspection or advice on bringing your board into the 21st century.

 

2. MCB - Miniature Circuit Breaker

MCBs are the evolved version of the ceramic fuse (Image 1.3). They work in the same way as the ceramic fuses with different ratings of protection for different sized cables, i.e. 10 Amp, 20 Amp, but now they are fixed and when one blows all you have to do is remove the issue that caused it to blow and flick it back up again! No need to replace fuse wires or remove the fuse, which reduces the chance of a mix-up. MCBs still, however, do not protect against electric shock.

Image 1.3: A switchboard containing MCBs of multiple protection ratings i.e 20 Amps .

3. Safety Switches

In 1992 safety switches became mandatory for power installations in new houses. Unlike ceramic fuses and MCBs they can protect against electrocution.

Safety switches were primarily invented because old protection, ceramic fuses and MCBs, only flick off when they detect too much heat/current in
the circuit preventing a fire hazard.  Safety switches monitor electricity in a different way. They work by looking for imbalances in what goes out of the switchboard down the active red wire and what comes back in on the neutral black wire. When someone is electrocuted they are funnelling electricity through their body. This causes an imbalance that is detected by the safety switch which is designed to trip, cutting off the circuit in less than 0.3 of a second, less time than a heart palpitation, preventing dangerous electrocution. It is now mandatory for safety switches to be installed on every new electrical installation and all alterations to existing power circuits. It has, however, taken a while for these necessary standards to be introduced. Let me take you through a brief history of the laws associated with the safety switch.

electrical safety - The history of safety switches

Phew, they got there in the end!

So you can see it took many years and many unfortunate electrocutions for these laws to be passed. 2018 saw the biggest change and the one that makes the most sense. With all circuits protected this now means
that thankfully all new installations of A/C, ovens, hot water units and all other hard-wired appliances need to be protected by a safety switch. These big units consist of large metal surfaces which could cause a serious electrical shock should a dangerous fault occur and in my opinion, this should have been one of the first laws to be brought out.

I know of an electrician who bought an investment property to do up. During the renovations, he decided to check the condition of the hot water unit.
As he went to take the cover off he was electrocuted to death. Due to a bad fault in the unit, the entire cover was live and there was no safety switch protecting that circuit to save him. Very sad story, I know, and this
guy was a qualified electrician. I also hear a lot of bad stories about plumbers getting hurt or killed from live metal pipes caused by bad faults, unfortunately, it’s even harder for plumbers to test for electricity as it’s not their trade.
Once you have all circuits in your home protected by safety switches you won’t be able to give yourself a serious electric shock even if you tried (unless you open up your switchboard, which I do not recommend!

So what does this mean for you?

Whether or not you have safety switches in your switchboard will depend on the year your switchboard was installed and whether you have had any alterations after the new laws were imposed.
If you still have unprotected circuits at your place you are not doing anything illegal providing all electrical work has been done to code by a licensed electrician. For safety’s sake however, I highly recommend you have safety switches installed on all circuits to protect your family from serious and possibly fatal electrocution. Elderly, kids and pets generally are the worst affected when electrocuted due to smaller and weaker hearts.

Types of Safety Switches

The first safety switch to be brought out was the RCD, this has now evolved
into the more modern safety switch, the RCBO.

1. RCD

The RCD protects against the risk of electrocution but needs to be added
to circuits with existing MCB or ceramic fuse protection (fire protection).
These can protect multiple circuits, but generally no more than three and
may be fitted within the switchboard (Image 1.4). Or if it is one of the earlier
models, it may be separate from the switchboard (Image 1.5).

electrical safety -Switchboard with one RCD
Image 1.4: Switchboard with one RCD (red dashed line). It protects the three power point circuits to the right indicated by the sticker ‘safety switch protected circuit/s’. The fridge, wall oven and light circuit are not protected by a safety switch.

2. RCBO

The RCBO is like an MCB and RCD combined in one. It prevents against
electrocution and fire on each individual circuit (Image 1.5).
The most likely scenario for the arrangement below is that they had their
power circuit MCBs protected by an external safety switch (RCD) before
2007 and then recently changed their light circuit MCB to an RCBO (combined
RCD and MCB – fire hazard and electric hazard protection
in one).

Image 1.5: Here you can see an RCBO (blue dashed line) protecting the lights and an old-style RCD (red dashed line) protecting the two MCBs for the power circuits (marked ‘pow’ above). The circuits which the RCD protects will usually be written on or near it (see black arrow above). Also note the test buttons on both safety switches (white arrows).

Identifying a Safety Switch

Test Buttons

Another way to identify a safety switch is to look for the test button (Image
1.6). You should test your safety switches regularly by pressing the test
button and then checking that the circuit shuts off immediately.
There is also a good trick you can use to quickly identify if anything in your
house is unprotected. Push all the test buttons then go inside and check if
anything is still working; perhaps your lights, oven or A/C units. If they are
working then this indicates that they are not protected by a safety switch
and you should call an electrician to get them protected.

Image 1.6: Shows an example of a test button marked with the letter ‘T’ and indicated by the arrow.

How to Prevent Electrocution in Your Home

Upgrade your switchboard

1. Ceramic fuse switchboard

If you still have an old board with ceramic fuses or if your switchboard
is a scatter of different protective devices which have been added over
time (Image 1.7) then instead of adding individual safety switches, it may
be a good chance to upgrade to a modern enclosure and put all of your
circuits on to individual safety switches. This is something you can discuss
with your electrician to find out which option is best for you.

Image 1.7: Here is an example of an apartment block with a communal board area. People have been adding new MCBs in individual enclosures and trying to squeeze them in wherever they will fit, and on an asbestos backing board as well! One apartment has an old school RCD (red dashed line) but there is still a lot of potential here for someone to get hurt downstream. Let’s just hope that no cowboys have re-wired the ceramic fuses with fence wire or anything else creative over the years!

Asbestos warning :

If you have an older style switchboard another factor to look out for is  whether it has an asbestos back panel.  If you are going to upgrade your switchboard you should ask your electrician to remove this. If you don’t do it when the board is upgraded then it will most likely never be done.  

The issue is that with most minor repairs the board will need to be drilled and this creates airborne dust, which as we all know is nasty stuff.

If I have to drill into an asbestos board I use a special three filter vacuum as well as a spray bottle to try and minimise this hazard as best as possible.

2. Modern Switchboards

The good news is that if you have a modern switchboard enclosure it is relatively straight forward to convert unprotected circuits that have only basic MCB protection (fire protection) to an RCBO safety switch which has built-in electric shock protection. Let me walk you through an upgrade.

Example upgrade:

1. The switchboard in Image 1.8 had two MCBs for the power point circuits (yellow dashed line) protected by an RCD safety switch (red dashed line), but all other circuits had no electric shock protection.

electrical safety - MCB Protection
Image 1.8: Shows the original switchboard. All circuits had basic MCB protection except the two power point circuits (yellow dashed line) which had added electric shock protection from the RCD safety switch (red dashed line)

2. I replaced the MCBs with RCBO’s (individual safety switches), (Image 1.9). Now all circuits were fully protected and this family couldn’t electrocute themselves inside their house even if they tried!

Image 1.9: Shows the upgraded board. All previous MCB’s have been upgraded to RCBO safety switches which have built-in electric shock protection. You can tell they are safety switches because of the (blue) test button, indicated by the arrow.
Check List

2. Earthing Your Home

A healthy earth connection is a crucial factor in your house electrical system.

Electricity points in your house need to be grounded via the main earth link at your switchboard.

If a fault occurs, perhaps within an appliance that is plugged into the wall, the earthing system can immediately direct the fault to earth via your switchboard, helping to switch off the electricity on that circuit before any damage is caused.
If your house is not earthed properly the dangerous fault current can stay ‘floating’ in parts of your house. Yikes!

Is Your Home Safely Earthed?

Electrical Earth Rod

If your house is earthed to current standards you should be able to see the top of a long copper earth rod sticking out of the ground, usually near or under your switchboard (Image 2.1).

electrical safety - Electrical Earth Rod
Image 2.1: This is what to look for when trying to determine if your house has an earth rod. If it has been installed by professionals it will also have gal spray-paint on the connection to avoid rust and corrosion.

Can’t see the top of your earth rod?

This most likely means that you have an old house where your earthing system is simply a wire connected to your water pipes (Image 2.2 and 2.3). This type of earthing is no longer allowed as the primary method to earth a house and can also cause numerous safety issues.

Image 2.2 : Shows the main earth connected under the house which, believe it or not, still has a solid connection (that is providing the wire hasn’t been cut upstream by accident or ignorance over the last few decades).
Image 2.3 : Shows an earthing system from the switchboard that consists of a few loose wires wrapped around water pipes which are not even forming a secure connection. This is really dangerous on so many levels.

If you suspect your house is still earthed in this way, then best to contact an electrician to have an underground earth electrode installed to bring  your earthing system up to current standards.  Another thing to keep in mind is that lightning strikes, falling branches and grid problems are all possible causes of an electrical surge which can travel through your switchboard. 

Without surge protection and a solid earthing point, these can cause serious damage (see next section for more info).

Are Your Appliances Protected From a Surge?

Did you know that surges in power that happen externally to your house can affect the appliances in your home?

Small surges can go unnoticed but over time they can shorten the life of your appliances and big surges can destroy everything in one fell swoop.  

The trick is to protect your appliances using surge protectors. Small individual surge protection devices can be plugged into each power socket to protect individual appliances. Or, even better, you can get an electrician to install a surge protector to your switchboard to protect all circuits. This, in my opinion, is a no brainer.

‘Have a surge protector fitted to your switchboard to protect your lights, appliances and even A/C units from electrical surges.’

1. Plug-in Surge Protectors

These provide a layer of protection between your gear and incoming surges. They are simply plugged into your wall socket and your appliance then plugs directly into them. When the house experiences an electrical surge the surge device is designed to shut off the power to the appliance before any damage is caused.

Take John for example:

John was aware of the dangers of power surges so he made sure his new iMac was protected by an individual surge protection plug-in device at the wall socket. When a storm hit his local area, John awoke in a sweaty mess to find his air conditioner had stopped working. He went to turn on his lights to investigate and they were gone too. Unfortunately, although his iMac remained unscathed, the circuits with the air conditioner, smoke alarm and lights had taken the full brunt of the surge and blown.

 To top it all off, the smoke alarm was constantly chirping in the background as the surge had wrecked it. Had John had a surge protector fitted to his switchboard and not just his iMac, everything could have been protected from the surge.

Don’t be like John, have a surge protector unit fitted to your switchboard and protect not just your most favoured appliances but all the electrical  components in your home.

2. Switchboard Surge Protectors

As we now know, the switchboard acts as a safety and distribution device for electricity. When surges come in, by nature, excess voltage is distributed down the path of least resistance and here’s where the switchboard surge protector unit comes in. It’s actually a surge diverter, because it takes this excess surge in voltage and as soon as it enters your switchboard,
instead of the dangerously high voltage being distributed through all of your electrical circuits and frying your equipment, it is safely directed down your main earth cable and through your earthing system. As we have already discussed this earthing system should be an earth rod to the ground.

Check List

3. Main Cut Off Switch

Just like the circuits in your house need protecting individually, so does your mains cable coming in from street power and also the mains cables that link up at the back of your switchboard. 

This is the job of your main switch. It needs to be rated to protect the  smallest mains cable to avoid fire hazards. 

All too often I come across old switchboards that are still using a manually operated main switch that provides no rating or protection from fire.

I also commonly come across mains switches that are not rated correctly for the size of mains cable it is supposed to protect.

Read on to learn how to identify the type of main switch you have and what you can do to protect your family from a fire.

Is Your Mains Cable Pre-1990’s and Can It Safely Handle Your Homes Power Consumption?

Main Switch

If you look at your switchboard you should be able to see a switch labelled ‘main switch’. Originally the sole purpose of this switch was as a means to easily cut off the electrical supply to your house.

Nowadays it can do a lot more than that and can act as the protection device for your whole
switchboard. It works like a circuit breaker and monitors the flow of electricity coming from the main grid and into your home.  

If installed correctly it will be rated to match the size of the mains cable systems, including the mains cable coming in from the street, and will trip off when the system becomes hotter than it is rated to handle (see images 3.1, 3.2 for examples of modern main switches).

Unfortunately, I still come across houses that are using an old main switch (see images 3.3 – 3.6). These can only be thrown off manually and have no rating to trip so they are unable to detect dangerous amounts of electricity entering the switchboard. They are infamous for burning out in an overload from the excessive heat produced and the cables they are supposed to protect end up catching on fire.

Recently a customer told me a story about the switchboard in their old house where they heard crackling coming from it and when they opened it up the whole thing caught on fire! I’m willing to put money on the fact that his old switchboard was not up to code.

electrical safety - Single phase MCB
Image 3.1: Modern main switch, single-phase MCB (red dashed line).
Image 3.2: Modern main switch, threephase MCB (red dashed line).
Image 3.3: Old school main switch, single phase (red dashed line).
Image 3.4: Old school main switch, three phase (red dashed line).

Asbestos Panels

If you have an old main switch then chances are that you also have an asbestos back panel as seen in images 3.4-3.6.

Sometimes these are labelled with a warning sticker, as seen in images 3.4 and 3.6, however, this is not always the case so it is best to ask your electrician to check for you, especially if you also still have ceramic fuses as this indicates that your switchboard has not been updated in a long time and you will likely have an asbestos back panel.

electrical safety -single phase
Image 3.5: Old school main switch (single-phase), indicated by the red dashed line. Also note the switchboard is on a black back panel, as the mains switch is old and ceramic fuses have not been updated this back board is likely to be asbestos.
electrical safety - Main switch
mage 3.6: Super old school main switch (red dashed line) on an asbestos backing board which in this example has a warning label (red arrow).

‘If you have an old main switch then chances are you also have an asbestos back panel - this is not always indicated with an asbestos warning label so it is best to ask your electrician.’

Mains Cable

The mains cable takes electricity from the grid to your switchboard. The main switch (which should monitor the electricity your house is consuming) and the mains cable both need to be matched to the electrical demands of your household.  

All too often I see mains cabling that was installed pre-1990’s to supply families back in the day with their black and white TV and a few lights.

Now, with more power guzzling appliances and A/C units etc., the original mains cable can no longer safely handle the increased demand for energy

in the home. This is when it is crucial that the main switch is a modern circuit breaker (MCB) rated to match the size of the cable so it can switch off to prevent a fire.  

If you suspect your house may be using a smaller old mains cable then it is best to call an electrician for an inspection and possibly upgrade your mains cable for maximum power capacity to your household or, at the very least, protect the old mains cable with the correctly rated main  switch.

‘With ever-increasing energy demands, many older homes now have a mains cable and main switch that are not rated correctly and pose a potential danger.’

Check List

conclusion

If your child sticks something in an electrical socket, your dog chews through a power lead, or you touch a dodgy switch, are you confident that your switchboard  can protect you from serious electrocution?

Or, in the case of a fault, are you confident that your switchboard can prevent an electrical fire?

During my day to day life as an electrician working in Sydney, I regularly come across a lot of dodgy and unsafe electrical installations as well as a lot of old gear that should be in a museum, not protecting people’s homes! 

I have found myself having the same conversations time and time again, sharing my expertise and explaining and educating my customers about how to make their homes safe. I then thought to myself – how can I get this message out there to help more people in a shorter space of time?  

So here we are, I have compiled all the common issues I encounter and have written a short, simple guide to share with you.  This is part one of the Homeowners Guide to Electrical Safety
covering switchboards, the source of your homes electricity and what should be the electrical safety hub for your family.

Part 2 and 3 will also be coming soon and will cover topics including; internal cabling and tripping issues, A/C and hot water efficiency, lighting and LED upgrades, smoke alarms and electrical tips and tricks. You can email me at contact@localandlicensed.com.au to request a free copy.

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