By installing those little glass cylinders with mettle ends from Pep Boys or
NAPA we may have set the fuse for disaster.
Recently, I read an article describing the difference between American and
European Standards in fuse design. It seems that British Standard fuses
conform to the International Electrotechnical Commission (IEC) Standards where
in the US we use fuses marked with the American UL/CSA AGC standard markings.
In each case the fuses are designed to protect the circuit wiring and attached
components from overloads. However, the standard for wire also differs between
Europe and the US giving rise to a problem we may be experiencing.
Way back when I replaced my first fuse in my '64BJ8, it never occurred to me to
look and analyze the fuse I was replacing. I simply went to my local parts
dealer and purchased a 35 or 50 amp fuse and installed it in the appropriate
slot. Since I very seldom had to replace a fuse, I gave it little
thought....until I had a short in my license plate light (inline fuse installed
after) and muttered the commonly heard "dammed LUCAS!!!".
Well, Lucas may not have been the culprit. It seems that an AGC 50 amp fuse
will hold sustained flow to a little above its marked max (50 amps) and AGC 35
will provide similar 35+ amp protection. However, under IEC standards, a fuse
marked IEC 50 will maintain a sustained max of 35 amps before failing and a IEC
35 will hold to around 17.5 amps. These differences are consistent with the
difference in wiring insulation standards they were designed to protect but, as
you can see, may be the cause for power overloads and burned wires in our cars.
I have no idea if the standards back when the Healeys were new are consistent
with ICE or AGC but it seems to me that a lack of manufacturer communication
and misunderstanding may have been the cause of our burned wires and not
"dammed LUCAS".
I would appreciate thoughts and comments.
Ray
'64BJ8
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