We have received a question from William, one of our customers, who needs assistance with some handyman work on the fuses in his home.
Question:
I want to change my old fuses to circuit breakers. The old fuses are 36A, 30A, 16A and 20A. I can buy the 16A and the 20A, but Bunnings don't have the 36A or the 30A. They have a 40A and 32A. Also I put in a 3600W hot water service what fuse should be used in it?
Answer:
Firstly, thanks so much for your email. We are more than happy to help you out with some advice. You mentioned that you were sourcing the new circuit breakers from Bunnings and doing the work yourself. While companies like Bunnings make it so easy these days to do a lot of renovation, repairs and upgrades ourselves when it comes to your home's electrics, we do recommend that you get an expert in to do the work for you.
Below is Some Information That Can be Found Around the Web Which Explains Why:
The Types Of Circuit Protection For Your Home
Ceramic Fuses
Plugin Circuit Breakers
The next development in fuses technology was a replacement plug-in (plugin MCB) circuit breaker that can be inserted into the old porcelain fuse base. These were a step forward from juggling fuse wire in the dark, but still only have the same protection as fuses. They are a risk because handymen are able to swap them around with the wrong ratings, which can potentially overload cabling which is very dangerous for the electrical protection of a home.
These are the sort where you run fuse wire around some screws (usually in the dark while holding a torch) before plugging them back into your fuse box. They provide short-circuit and overload protection and provide limited protection to your property and no protection from electric shocks.
Hardwired Circuit Breakers
The first hardwired circuit breakers (MCBs) were a step up for safety in that they couldn’t be swapped around by over-enthusiastic DIYers. Although quicker acting than fuses or plug-in breakers, they still only provide short circuit and overload protection.
These fuses should be used in conjunction with a Residual Current Device (RCD). RCDs act as circuit breakers as well as safety switches. These are highly recommended for the safety of yourself and anyone else within your home.
Residual Current Device (RCD)
Safety switches or RCD were the next huge step forward, as they not only protected a number of circuits but they also protected against electric shock for the first time. Generally, one safety switch is linked to a number of circuit breakers.
The main drawback of this was that when they are tripped, they take out supply to an entire house. As you can see, there are benefits and shortcomings to all of the solutions above. So what is the solution?
Combination Safety Switches/Circuit Breakers
The most modern type of switch is a combination of safety switches and circuit breakers (RCBOs). These protect single circuits from shorts, overloads and electric shocks. This means any problem is confined to that one circuit and will not take out the circuits for the rest of your house.
The other advantage is that nuisance trips become a virtual thing of the past as each circuit has its own “earth fault” limit as opposed to having one safety switch protecting numerous circuits.
Summary
If your home has ceramic or plug-in fuses, it’s crucial to upgrade your fusebox to current standards. This should be done by a licensed electrician to ensure safety. For those with older-style circuit breakers or multiple breakers connected to a safety switch, it’s recommended to replace them with combination switches (RCBOs) for added peace of mind and to prevent nuisance tripping.
More information on when to upgrade your switchboard can be found in the article “How much does it cost to replace a switchboard“.
At The Plumbing & Electrical Doctor, our trained and licensed electricians can provide you with expert advice. Our services are available in Newcastle, Canberra, Hunter Valley, Lake Macquarie, and Port Stephens. Contact us today to schedule a consultation.
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