Without a fuse, a surge will destroy your equipment. That is the best-case scenario. In the worst case, the wires in the power cord will melt, starting a fire and burning your home to the ground. In some cases, a wrong fuse is just as bad as having no fuse. You don’t want to add the wrong fuse to the plug. The consequences could be disastrous. You have two situations that frequently occur!
Can I Use A 13A Fuse Instead of 3A, 5A Plug?
If you add a 13A fuse to a 5A cable, the appliance will force the plug to transmit more electricity than it can withstand. The fuse won’t respond until the current exceeds 13A. But the conductors connected to the 5A plug will melt long before the current reaches 13A. Thus, I won’t suggest using a 13A fuse instead of 5A & 3A.
However, no one can prevent you from fitting a plug with a fuse of any rating, especially if the slot in the plug can accommodate the fuse you have in mind.
Is this practice safe?
The answer is a definite no. Just because you can do something doesn’t mean you should do it. Admittedly, there are plenty of anecdotes on the internet from people who used 13A fuses in plugs with low ratings, and nothing bad happened to them.
But those anecdotes don’t mean anything. They are the exception, not the rule. You should only use 13A fuses in 3A – 5A plugs when you fully understand and appreciate the consequences you may suffer as a result.
What Does Fuse Do In A Plug?
A fuse performs the same function as a circuit breaker. In fact, some older homes have a fuse instead of a breaker. The BBC describes a fuse as a device that responds to excess current.
It has a wire that melts when exposed to more electricity than the fuse’s rating permits. For instance, if you expose ten amps to a 3A fuse, the wire will melt. This stops the flow of current.
Technically speaking, the fuse protects the wires in the power cord, not the appliance. Though, by defending the power cord, the fuse inadvertently protects the device from harm.
You cannot fix a fuse. Once it dies, you have to get a new one. You get these devices in three primary ratings: 3A, 5A, and 13A. But 5-amp fuses are a rarity these days.
Your local store will probably limit your options to 3A and 13A. Some retailers sell fuses in non-standard sizes like 2A, 7A, and 10A. But you don’t have to perform any calculations to identify the correct fuse for your plug. Just replicate the rating of the old fuse.
For instance, if your manufacturer uses a 5A fuse in their plug, you should also replace it with a 5A fuse. The manufacturers know what they are doing. Follow their lead.
If you don’t know the rating of the old fuse, calculate the amp rating of your appliance. This will give you an idea of the fuse rating you should target.
For example for a 100W table lamp – Dividing 100 watts by 240 volts gives you 0.42 amps. Therefore, the table lamp uses 0.42 amps. But you’re not done. You should add 10 percent to the final figure to be on the safe side. This gives you 0.46 amps.
You don’t need a fuse of 0.46A or even 1A. Three amps will do.
Just choose the closest match to your equipment’s amperage. If you have a 10A kettle, add a 13A fuse.
Some plugs have a rating that shows you the appropriate fuse to use. But if yours doesn’t have one, and you don’t trust your calculations, call the manufacturer and tell them your predicament. They will recommend a fuse.
What Happens If You Use The Wrong Amp Fuse?
Fuses with smaller ratings are a nuisance because they keep blowing even though an overload hasn’t occurred. While a small fuse is a nuisance, a large fuse is a threat.
The appliance can safely utilize 13 amps. But the fuse doesn’t know this. It has a wire that melts once the current exceeds three amps. You will replace the fuse repeatedly in the absence of a proper overload.
Some people use oversized fuses in emergencies. They know that an appliance with a 13A fuse won’t necessarily use 13 amps. But a large fuse is still a risk.
Plug Test has revealed a rule that most professionals follow. They expect consumers to use 3A fuses for appliances with ratings of 700 watts or less and 13A fuses for appliances of more than 700 watts.
Difference Between 5 Amp and 13 Amp?
- You can use 13A fuses with heavy-duty appliances such as washing machines, kettles, and irons. Devices with electric motors require oversized fuses regardless of their amp ratings because they use more energy when they start.
- Small items like lamps, televisions, and blenders can use 3A-5A fuses.
What About Using 5A, 3A Fuse In A 13A Plug?
If you use a 3A fuse in a 13A plug, it will blow the moment the device uses more than three amps, even though it can safely use 13 amps.
3A and 5A fuses in a 13A plug will irritate you.
This isn’t a problem if the equipment’s electrical draw stays below 3 or 5 amps. But you shouldn’t take the chance. Get a fuse that matches the rating of the plug.
Can You Use A 10 Amp Fuse Instead Of 5, 7.5, 8 Amp?
A 10A fuse is a better option for a 13A plug. Many devices with 13A plugs rarely exceed ten amps. But if those devices have electric motors, a 13A fuse can accommodate the spike that occurs when you switch them on.
This is the mistake some people make. They add 10-amp fuses to 10-amp appliances that have motors without realizing that the device will use more than ten amps when it cycles on.
Can I Replace the 7.5 Amp Fuse With A 10 Amp Fuse?
If the plug came with a 7.5A fuse, a 10A fuse is risky. You can still use it. The difference between 7.5A and 10A is small. But the wrong appliance can start a fire if it forces the power cord to transmit more current than it can handle.
Check the wattage of the device. Some appliances have plugs with a larger amp rating than they use. In other words, a device with a 13A plug may not necessarily use 13 amps. In fact, it may use less than half of the plug’s rating. This is not an excuse to add the wrong fuse. But it gives you more room to breathe.
You can experiment with light-duty equipment because it has a lower electrical draw. Heavy-duty appliances use too much electricity for you to take a chance on the wrong fuse.