House of Horrors

Max Demian wrote:
"Peter Thomas" wrote in
message

I used to see a lot of this stuff. What happens is the primary
winding of the miniature power transformer gets shorted turns
and gets very hot. Even in this condition the amplifier can
continue to work, until the fuse blows. I would expect the
internal protection to kick in first of course, the plug
fuse blowing suggests catastrophic failure.

It's worth noting that the vast majority of electrical items in the
home (but not mine) have plug tops that are equipped with 13A fuses -
coz it says on the plug 13A !!

Well a 13A fuse will blow in the event of a dead short in the lead or
the primary of the mains transformer, and a 3A one *won't* blow in
the event of a more subtle fault such as a short in the output from
the mains transformer - so I reckon 13A for everything provides as
much practical protection as a 3A, even for low consumption
appliances.

What absolute nonsense! If you put a 13amp fuse in most appliences then the
flex becomes the fuse.

"Dave Plowman (News)" wrote in message
...
In article ,
Prometheus wrote:
Fuses do fail with age; I have had a few which have failed after many
years operation, when I check the current consumption I find it to be as
expected, so I replace the failed fuse and the kit continues to work.

That can apply to a fuse working near its rated value - it continually
expands and contracts as it's powered up and down etc. A 3 amp fuse
feeding a DA might as well be a lump of solid brass as regards heating
effect.

Furthermore there's no on/off cycling, other than 'on' in 1976 when you
install it and 'off' in 2007 when you bin it.

Bill

"Ivan" wrote in message
...
I've also come across a number of setback labgear masthead power supplies
which judging by the brown burn marks on the case have got a bit too hot
for comfort.

Yes, I've seen exactly the same thing.

Bill

"Dom Robinson" wrote in message
...
In article ,

says...

I have standing orders from one of the local authorities I work for to
automatically replace any active device I find that is more than 20 years
old.

Does that include the management working there?

It probably does but the issue hasn't arisen.

Bill

In article ,
Bill Wright wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Prometheus wrote:
Fuses do fail with age; I have had a few which have failed after many
years operation, when I check the current consumption I find it to be
as expected, so I replace the failed fuse and the kit continues to
work.

That can apply to a fuse working near its rated value - it continually
expands and contracts as it's powered up and down etc. A 3 amp fuse
feeding a DA might as well be a lump of solid brass as regards heating
effect.

Furthermore there's no on/off cycling, other than 'on' in 1976 when you
install it and 'off' in 2007 when you bin it.

except when there is a supply failure or a circuit breaker trips, or ....

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

"charles" wrote in message
...
In article ,
Bill Wright wrote:
except when there is a supply failure or a circuit breaker trips, or ....

That doens't compare with an appliance that's powered up once daily (for
instance) though.

Bill

On the subject of plug fuses,
Most of the equipment I install is powered by an IEC
13A plug (kettle lead)
No it isn't, a kettle lead is a "Hot Condition" socket, and has a cutout
in it. The leads you mean won't fit into a kettle.


Glad to see you're awake at the back. I should of course used
quotes or a "so-called" qualification rather than parentheses.

Remember those round kettle plugs that auto-ejected if the
kettle boiled dry?

--
Graham.
%Profound_observation%

"Graham." wrote in message
...

On the subject of plug fuses,
Most of the equipment I install is powered by an IEC
13A plug (kettle lead)
No it isn't, a kettle lead is a "Hot Condition" socket, and has a cutout
in it. The leads you mean won't fit into a kettle.


Glad to see you're awake at the back. I should of course used
quotes or a "so-called" qualification rather than parentheses.

Remember those round kettle plugs that auto-ejected if the
kettle boiled dry?


Is there any other kind?


--
Graham.
%Profound_observation%

"Ivan" wrote in message

"Graham." wrote in message
...

On the subject of plug fuses,
Most of the equipment I install is powered by an IEC
13A plug (kettle lead)
No it isn't, a kettle lead is a "Hot Condition" socket, and has a
cutout in it. The leads you mean won't fit into a kettle.


Glad to see you're awake at the back. I should of course used
quotes or a "so-called" qualification rather than parentheses.

Remember those round kettle plugs that auto-ejected if the
kettle boiled dry?

....unless the plug was up against the wall.

Is there any other kind?

You must have a *very* old kettle.

--
Max Demian

In article ,
Adrian A wrote:
What absolute nonsense! If you put a 13amp fuse in most appliences then
the flex becomes the fuse.

Have you checked on the cross sectional area of 13 amp fuse 'wire' against
that of the cable in most appliances these days?

--
*'ome is where you 'ang your @ *

Dave Plowman London SW
To e-mail, change noise into sound.