On Fri, 23 Mar 2012 13:33:04 +1100, "Phil Allison"
wrote:
"Jeff Liebermann"
The coffee distillery is double insulated, which means it doesn't need
a ground pin on the power plug. Since a fault can affect either side
of the power line in such a symmertical arrangement, two fuses are
required.
** Horse manure.
Yep. My neighbors just unloaded some Llama manure in their "garden".
Doesn't smell too bad.
One fuse is sufficient to break the circuit in case of current overload.
http://www.freewebs.com/valvewizard/fuses.html
Some appliances use two fuses, one for live and one for
neutral. While there is some argument against using a
neutral fuse, there is no law against it (in the UK anyway).
You can buy IEC inlet sockets with built-in fuse holders,
which greatly simplifies construction.
http://www.appliance411.com/faq/dryerheat.shtml
There are 2 fuses or breakers for the dryer, both must
be good in order for the dryer to function properly.
Note that the thermal fuses also act as an internal short
protector.
** Even worse horse manure.
Well, there are things worse than horse manure. I've never tried
skunk manure, but I suspect that would qualify.
Thermal fuses act on temperature, not current at all.
True.
The max current rating given by makers is based on self heating to ensure
the fuse stays within temp rating tolerance.
The max current rating is the maximum current at which it will operate
safely without self-heating and blowing the fuse. I found out the
hard way that it's much like the rating on a typical wire fuse. If
you run a 5A fuse, at 5 amps at room temperature, it will eventually
blow. Same with a thermal fuse. If you run it near it's rated
maximum current (usually 5A, 15A, or 30A), it will eventually get warm
enough to melt the wax and trip the fuse. With a short circuit across
the power line, the self-heating will blow the thermal fuse almost
instantly. It's not designed to be a power fault protection device,
but does the job nicely anyway.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558