I've read that one should place the fuse on the live wire. But as I gather, USA and UK use 3-prong outlets that let you insert plugs in one way only, so that live and neutral never get swapped inside the equipment.
So where do I put the fuse now? Should I apply two fuses?
More interestingly, what should I do with the metalcased/grounded PSU that I have ordered from abroad and has the fuse only on the live wire?
But I've read many times, that the main reason for putting the fuse on the live is to prevent the rest of the circuitry from getting to live potentional in case of a failure. Even though the fuse gets blown and no current can flow between live and neutral, the circuit can stay at live potential, because the fuse interrupted only the neutral wire. Isn't it so?
But I've read many times, that the main reason for putting the fuse on the live is to prevent the rest of the circuitry from getting to live potentional in case of a failure. Even though the fuse gets blown and no current can flow between live and neutral, the circuit can stay at live potential, because the fuse interrupted only the neutral wire. Isn't it so?
You shouldn't open a device for repair or to replace a fuse using any kind of wall outlet and plug.
Even knowing that the fuse interrupts live there will still be live on a PCB when not removing the device from mains and be a potential hazard as well.
User's manuals generally say: Remove power before opening.
The fuse isn't mainly in the circuit to protect "dummies", but to protect the circuit.
Sounds reasonable, I was just thinking about safety reasons.
Let's consider this: in the case of Type F plugs, if live and neutral get swapped then the fuse is on the neutral. Now what if the live gets shorted inside the equipment to earth, but through some components that limit the current somewhat to a few amps, not enough for the circuit breaker to shut down, but enough to cause fire. If the fuse was on the live, this situation couldn't happen as the fuse would blow after a few seconds of overcurrent.
Your fuse inside the enclosure won't have a chance to blow in case live gets shorted to earth (protective earth), because the earth fault circuit breaker reacts much faster than a fast blowing fuse.
Those circuit breakers are mandatory by law in Germany not only in industrial facilities but also in households.
They trip at a fault current of 15 to 30mA, depending on the setting (two options).
Don't worry about where to put the fuse. Put it either into live or neutral.
Once again. The fuse is there to protect the circuit.
Your fuse inside the enclosure won't have a chance to blow in case live gets shorted to earth (protective earth), because the earth fault circuit breaker reacts much faster than a fast blowing fuse.
Those circuit breakers are mandatory by law in Germany not only in industrial facilities but also in households.
They trip at a fault current of 15 to 30mA, depending on the setting (two options).
Don't worry about where to put the fuse. Put it either into live or neutral.
Once again. The fuse is there to protect the circuit.
My primary misconception was to think that the earth fault circuit breaker will react only after many amps, but it's clearly not the case. I don't know why I thought this...
My primary misconception was to think that the earth fault circuit breaker will react only after many amps, but it's clearly not the case. I don't know why I thought this...
Other than the device fuse the earth fault circuit breaker was designed to protect persons. They would be well fried after sustained application of several Amps.
Other than the device fuse the earth fault circuit breaker was designed to protect persons. They would be well fried after sustained application of several Amps.
Your fuse inside the enclosure won't have a chance to blow in case live gets shorted to earth (protective earth), because the earth fault circuit breaker reacts much faster than a fast blowing fuse.
Those circuit breakers are mandatory by law in Germany not only in industrial facilities but also in households.
After a bit of further research, it became clear that earth fault breakers are not mandatory in my country, so a regular household can be safely expected to have an overcurrent-type breaker only. This can pose a fire hazard in the situation that I've described previously, couldn't it?