Nowadays, fuses are being replaced in favour of circuit breakers, but the functionality of the fuses is still relevant.
Role of a fuse
A fuse is a safety device that protects against short circuits and overloads. The fuse is in the form of a cylinder made of glass or ceramic, with a filament passing through its core.
This filament melts (hence the name fuse, which means “can melt”) when subjected to excessive heat caused by an overcurrent. This has the effect of breaking the circuit and protecting the equipment against possible damage or fire hazards.
Types of fuses
Fuses are found in older electrical installations, where they can be 10 A, 16 A or 2 A or 32 A (A stands for amperage).
A 10 A fuse is sufficient for lighting, but for a hotplate, oven or three-phase socket, higher amperage (16 or 32 A) is required.
What to do when a fuse “blows”?
When a fuse blows, it is important to identify what caused the circuit to be broken and to repair or replace a faulty appliance if necessary.
When the blown fuse has been identified, the power must be cut off by placing the circuit breaker in the off position, changing the fuse and then turning the power back on.
Good to know: When you buy your fuse, always choose fuses that have a light that comes on to indicate that they have blown.
Disadvantage of fuses
A fuse is only used once and must be changed if it has “blown”. This is why circuit breakers (see further below) are increasingly being used. They have the advantage that they can be reset at will.
The price of fuses varies according to their amperage. Count:
– between $3 and $5 approximately for a box of 10 fuses of 10 A or 16 A;
– between $5 and $7 for a box of 10 fuses of 32A.
Types of circuit breakers
There are 3 types of circuit breakers:
– the general or branch circuit breaker;
– the divisional circuit breakers;
– earth leakage circuit breakers.
General circuit breaker
The main circuit breaker protects the electrical installation and people. It ensures the emergency shutdown of the entire installation in case of a problem.
It is set according to the subscription (power) chosen by the user. If too many electrical appliances are operating at the same time and exceed the power subscription, it breaks and cuts off the current.
However, this circuit breaker is not sufficient to ensure the protection of your installation. Other devices (as seen below) must be installed.
This circuit breaker must be installed inside the housing, in the electrical panel.
Subdivisional circuit breaker
Subdivisional circuit breakers ensure the protection of the various electrical circuits of your installation.
In the event of a problem, it breaks the circuit responsible for the overload or short circuit.
Its handle is lowered so that you can see which circuit is involved. Once the problem has been solved, for example, after disconnecting the electrical appliance causing the problem, simply raise the lever to restore power.
Earth leakage circuit breaker
It is a highly sensitive differential circuit breaker (30 mA) that protects circuits from overloads and short circuits but also protects people from the risk of electric shock.
The sensitivity corresponds to the tripping (i.e. breaking) threshold in the event of a current leakage.
For domestic installations, a high sensitivity of 30 mA or less is required.
Price of a circuit breaker
Count between $3 and $75 (depending on the model) for a phase + neutral circuit breaker composed of a single module.
Replacing fuses or circuit breakers may not always be a simple task for many DIY enthusiasts. A simple misplacement could cause irreversible damage not only to your home electrical circuit but also to all your domestic appliances. This can result in a further dangerous situation for people in the house. The best solution if you need to repair your electrical installation is to call on professionals who know what they are doing. Don’t risk your life and that of your loved ones!
That said, you can contact Eccles Electrical Contractors for all your electrical needs, from the replacement of blown fuses to the installation of circuit breakers. They are electrical installation specialists operating throughout North Melbourne, Vic. They will be able to give you a quote for your electrical upgrades.
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