What exactly is the difference between a surge protector and a fuse? Can a fuse protect the electronic devices from lightning instead of surge protector?
Last Updated: 02.07.2025 14:54

Lightning arrestor is a spark-gap device, and can be installed anywhere. What is important, is that the wire is thick enough to withstand the lightning bolt and conduct the energy away from the building.
so, the loop of wire then, when put together with another loop reduces the ‘noise’ on a power line.
Is the question then , "why buy a surge supressor, if the fuse alone protects the electronic circuits from a lightning bolt?".
Prelim Results | UFC Fight Night: Blanchfield vs Barber - UFC.com
The other is “what does a “fuse” do?”
Fuses, on their own, then operate much slower than the MOV variable resistance, during the lightning strike.
(Dc diagram shown, AC is similar).
China Auto Body Slams ‘Vicious Competition’ After BYD Price Cuts - Bloomberg
What is lightning?
He then asserts :
A circuit breaker is similar, but is resettable.
Gut Microbiota Transplants May Cause Long-Term Imbalance - Neuroscience News
Would individual surge supressors have save this equipment? most likely, since the surge supressor would take the jolt instead of the electronic components.
There are two important concepts here.
Once the voltage goes over 0.0650 volts, then this fact can be used to amplify the difference, and turn the circuit breaker off , furthur down the line. Essentially that is what a RCD/GFCI does, it compares the incoming current, to the outgoing current, and if the difference between the two currents is over 5mA, then it trips the circuit breaker.
A fuse is a non-resetable over current circuit protector.
This device then solves the entire problem.
Edit 2024–10.
I can't stop thinking about this plotline in 'Materialists' - NPR
These are simplified answers to the original question, and does not change anything I wrote above.
These devices are installed between the “hot” and “neutral” and protective ground.
So combined with a device called a MOV or Metal-oxide-resistor, then forms the 3rd part of a “surge suppressor “.
They Finally Opened the Moon – What Scientists Found Inside Changes Everything - The Daily Galaxy
One
He then describes Rainy Season and Lightning.
eight
I Can't Wait for Apple's F1 Movie. Its Haptic iPhone Trailer Has Me Even More Excited - CNET
This is where this question deviates from being a 'generic' question, and becomes more specific.
There is no harm in having the surge suppressor along with the fuse in the circuit. The fuse will not open up until the current melts the link. This will take time, and in the interim, that jolt will get transmitted into the power supplies.
I post the exact comment here.
Stop Work Orders At NASA JPL - NASA Watch
It’s been three xxx five werks, and there has been no response to my follow on query on his Commment to my answer.
The bolt then partially travels down the line to your home.
(There is no concept of polarity, in the loop because the current changes direction 100 to 120 times a second (power frequency).
“ … to protect building, lightning arrestor, is provided above building and directly connected to earth.”
He then describes the function of a fuse.
2024–10–00 [ Ammar Mahdi ] Ammar Mahdi
Is This a Real-Life ‘Jaws’ Situation? - AOL.com
This is the picture of an electronic coil of wire wound around a core of magnetic material.
so, what happens?
This is 'the assistant's answer'
Acting NASA Administrator Janet Petro June 6, 2025 - NASA Watch
The third is lightning and “how it gets conducted into a home.”
2024–10–14 [Omar Gharbi Omar Gharbi ]
It also is a device that limits the change in current flow.
4 everyday habits that help prevent heart attacks - Times of India
Because the load is inductive, the current lags the voltage.(by a bit).
but this device (an Inductor) … impedes the rapid changes in the current.
This is an electronic circuit designed to clamp voltages so that the Voltage Potential that appears at the outlet is never going to exceed the nominal value.
A fireball over desert mountains photo of the day for May 30, 2025 - Space
At the secondary, it is 1000 times less.)turns ratio). If it gets hit with a 100,000 volt bolt of lightning then the voltage arrestors conduct and clamp the voltage down to line voltage, ( but a small amount leaks down the line). This is the problem.
what exactly is a ‘surge’ protector?
There are three different concepts here that are getting confused.
What is a common thought that keeps people up at night? Why do some people experience this?
But it can get overloaded, and no longer works.
OK, this is Mohan Rajaratnam’s definition of a Surge suppressor.
Now when you have a certain ac resistance, then a current flows in a loop.
At least they know the answer if they wanted it.
What does a fuse do?
but I think this circuit , shows a few more pieces.
But… the neutral is now “floating” because of the 1 ohm resistance.
This one hit behind the barn.
Barnstars:
In schematic diagrams this is the symbol for a fuse:
2024–10–10[John johnson John Johnson ]
[old diagram got deleted by accident]
If the nominal power is 4,000 watts then the current at 230volts is 16 amps.
a photo is worth a thousand words.
2024–10–11 [Bobby Sanchez Bobby Sanchez ].
[image of Common-mode choke]
Can the fuse protect the electronic devices from lightning instead of a surge protector.
P = e* I, so since I is 16 amps, then the voltage dropped is 1/16 volt or 0.0650 volts.
Here is a simplified AC power diagram.
2024–09–27 [ Mohan Rajaratnam Mohan Rajaratnam ] . Thinks you can get free electricity from nothing : Mohan Rajaratnam's answer to Is it possible to generate free electricity at home using a magnet or other low-cost methods? If so, how does it work?
the problem then depends on "how fast does the fuse operate?".
“ A surge suppressor is the one which is connected at the input supply so that when there is a sudden change voltage it bypasses thereby protecting the (circuit) and electronic components”
So, it’s possible that these devices from Trip Lite have addition suppression devices, these ones seem to be sturdy.
For this case there are devices called Metal oxide varistors (MOV).
And this is the problem alone. Is the power supply in the equipmemt designed with a lightning strike in mind? Some yes, others, no.
Upvotes:
But during the surge, the fuse will not blow if it is a longer duration and lower value )10 to 50%).
This is where the MOV conducts again, and dissipated the energy.
nine
First Sentence:
An AC voltage/ current source, and an ac inductive load.
“ A fuse is a device which protects the (circuit) against overload and short circuit.”
This is a photo where a lightning bolt took out a home's complete mains distribution box, and a lot of electronic gear as well.
One is “what exactly is in a ‘surge protector’ ? ”
It seems Mohan does not understand the difference between a comment and an Answer.
When the current is 200% of the rated value , it will “go open” (the link metal melts) and protect the device.
2024–10–16 [ OO OLAOYE OYEBODE ]
At one ohm, the resistor has a maximum of 1 watt power.
So, the voltage could go up to 500 volts, and the fuse will not open up.
2024–10–11 [Victor Olarewsju Victor Olarewaju ]
Mohan forgets that a fuse is a one-time device, and needs to be replaced if it is tripped.
This is a high voltage low current spike that comes down the line because of the power poles being struck, and the voltage suppressors activating on the primary side of the transformer.
The MOV will conduct when the voltage exceeds 50% of line voltage.