Why do people like you get so upset about dates? There was no best bef= ore date printed on my post, people are free to answer it whenever they = wish. Go get treatment for your OCD.
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Take notice: when this sign is under water, this road is impassable.
'cause it shows ignorance of the platform they are using to access USENET.
And in this case part of the late answer is wrong. Unless "just beyoud 100A" has been redefined to mean 2 or 3 times the 100A rated capacity and even then it'll take a while to blow (seconds to minutes).
Invalid assumption. Maybe they just don't mind answering older question= s.
They are pretty shit actually. I had a kettle running at 2400W (10 amps= ) on a 5A plug fuse which lasted for 3 months of using it several times = a day before it blew. And a colleague had 2 tumble driers and 2 washing= machines running on a 4 way power strip, which melted the strip into a = soggy mess and didn't blow the 13A fuse. Makes you wonder why we have t= hem at all. Surely they can design them to take triple load for 5 secon= ds (to allow for motors starting), then blow if it's over the rating aft= er that? Simply the temperature of the wire should reach a certain poin= t? But all we seem to have is "fast blow" which won't allow for motors = and "slow blow" which is in plug fuses and doesn't blow other than a dea= d short.
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Ireland's worst air disaster occurred early this morning when a small tw= o-seater Cessna plane crashed into a cemetery. Irish search and rescue w= orkers have recovered 2826 bodies so far and expect that number to climb= as digging continues into the night.
I'm inclined to agree. Hardly anyone other than sparkies is aware that any given mains fuse will pass a great deal more than its rated value for a surprisingly long time during which much melting or even a fire could possibly start. Such fuses are great for protecting against dead shorts, but not much beyond that.
Yup, the curve for normal incomer fuses is shown here:
A 100A one will carry 150A for a *long* time. Even 630A will take 5 secs to blow it.
You can buy fast blow fuses which are very good at protecting, but are no good for motors starting. Surely a compromise could have been made?
Fuses don't protect people plugging too much in (unless you nicely overrate the cable - my garage has a 30A cable with a 15A fuse, and the fuse will blow before the cable melts), but they do stop things happening like dodgy halogen spotlight bulbs shorting out. However they don't blow quick enough to protect transistors in PIR light switches, which is why I fitted circuit breakers for the lighting (that is until I put the lighting circuit on a UPS to make the LED bulbs last longer - the mains supply is shit and full of surges, brownouts, and terribly low and high voltages.)
Makes you wonder what f****it invented fusewire.
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Can fat people go skinny-dipping?
Err, the purpose of that fuse is to protect the wiring from melting and causing a fire. If it doesn't, it isn't correctly specified.
Or even those who think all fusewire is the same.
That bit is true, however...
That bit ought not be if the right fuse is used.
One of the absolute requirements for most fuses is that they offer adequate fault protection - and that implies protection of the wiring from melting and catching fire.
That's definitely not true. Its perfectly acceptable and normal to use a fuse for overload protection. Its also acceptable (and in fact desirable) that they will pass an overload current for a period of time, since they should reflect the thermal performance of the circuit as a whole. This is why the actual current level itself is less important than the "bigger picture" combination of current combined with duration.
(There may be cases where you don't require overload protection at a fuse however. Say for example at the origin of a dedicated circuit feeding a hard wired bit of equipment. Then the fuse only need offer fault current protection).
+1
The ones in plug fuses suck. You can melt a 4 way power strip before the 13A fuse blows. Just draw a steady 26A, like two heaters or tumble driers. Admittedly it didn't catch fire, but it could have set fire to something touching it.
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