On Friday, 3 January 2020 19:36:07 UTC, Dave Plowman (News) wrote:
In article ,
whisky-dave wrote:
********. The fuse in a plug is only there to protect the cable. If
the appliance needs a fuse it will be in or on it.

What appliances do not need a fuse?

Aga cooker. Gas ascots. My electric toothbrush doesn;t have a fuse, and
niether does the charging station (that I know of) the 2 pin plug goes
into an atapter which does have a 3 amp fuse in it IIRC, same as with my
shaver.

Things with a transformer (that might catch fire) often have a thermal
fuse in the windings. Non replaceable.

yes I know and those fuses aren't there to protect the cable unlike replaceable plug fuses are, that is the point.
I've added 1 amp in-line fuses to our 12V AC Transformers as added protection.


Relying on a plug fuse would be plain daft.

Makes you wonder why the BS 1362 regulations allow it then doesn't it
or are yuo saying they are wrong ?

All too easy to fit the wrong
one.

Who's problem is that ? Are yuo saying 13 amp plugs should be banned because people can put the wroing fuse in them ?


A fuse on say a radio etc that can be replaced has the correct type
printed beside it. No such thing on a plug.

Most plugs I've seen do have a rating embossed on them, the first 3 I've
looked at here do. 2 Have 5 Amp embossed and another has 10 Amp embosed,
all 3 have 5 amp fuses in them. But there;s nothing stoping an idiot cutting up a nail or putting in paper clip or anything else in the fuse holder.

https://www.rapidonline.com/mk-655-b...ghplug-23-1340

Just to the below left of the earth pin you can see 13 amp shown.

On Saturday, 4 January 2020 13:36:11 UTC, Dave Plowman (News) wrote:
In article ,
wrote:
On Friday, 3 January 2020 19:36:07 UTC, Dave Plowman (News) wrote:

Things with a transformer (that might catch fire) often have a thermal
fuse in the windings. Non replaceable.

often yes. And often no.

Relying on a plug fuse would be plain daft. All too easy to fit the
wrong one.

That you think it daft makes zero difference to the fact that that is
how it was done for a long time, and old appliances have not in most
cases sprouted an extra fuse since construction.

And long experience is why their aren't lots of values now used.

A fuse on say a radio etc that can be replaced has the correct type
printed beside it. No such thing on a plug.

No. It was reckoned that people could normally work out for themselves
that a radio should be on a 2A plug, and a toaster on a 15A, which have
since morphed into a 3A fuse & a 13A fuse in the square pin plug. Today
we know that often people don't know this stuff.

2 amp plug? Does that restrict the peak current to 2 amps?

No but most plugs & sockets have a current and voltage rating
and that is how you decide on which should be the maximum sustanable rating.
Those with enough inteligence know what these rating mean while it
might need explaining to others.

It's also why there are differtn types of fuses.
The most common fuses I buy are 1 amp quick blow glass bodied, which for one lab
we normally get through about 30-50 and another skills lab we get through a
similar amount each year.

The lowest current fuse I've bought is a 32ma, (a 20mm fuse) while the highest current fuse I have is a 500 amp. But strangley enough it won't fit in a
13 amp plug !
Because the fuse body is 210mm in lengh and 72mm in diameter.

I also have some 3/8th inch fuses and some 1 1/4" as well as the now standard
mains and 20mm types of which some are quick blow, semi delay, delay, and anti-surge. I try to keep a range from 50ma to 3.15 amp.

On Monday, 6 January 2020 11:26:10 UTC, whisky-dave wrote:

What appliances do not need a fuse?

Aga cooker. Gas ascots. My electric toothbrush doesn't have a fuse, and niether does the charging station (that I know of) the 2 pin plug goes into an atapter
which does have a 3 amp fuse in it IIRC, same as with my shaver.

Are you sure the charging station doesn't have some form of internal
fuse?

I assume it does but we are talking about appliancies where the fuse can be replaced. AFAIK my toothbrush does NOT contain a fuse.
The charging station should have a fuse as that is the ONLY section connected to the mains supply and in accordence with UK electrical safety must contain some sort of fuse, whether it is current or temperature driven,
resetable or not I don't know, but it is most likely a non-servicable pat the
a user shouldn't replace.

The statement was what appliances NEED a fuse and not whether they have one or not, there is a differnce there too.


If an appliance uses an "inherently short-circuit proof" mains transformer
for its power supply, it does not need any kind of fuse - not even an
over-temperature fuse inside the transformer.
I have designed such products and had them successfully tested by Intertek.

John

In article ,
Scott wrote:
In the days of radial 5 and 15 amp circuits, the fuse was in the CU. And a
15 amp socket would often have an adaptor. With no fuse.

Interesting question: were the 15 amp sockets and 5 amp sockets on
different circuits or mixed together?

In practice? Often mixed. In theory, you'd need to find the regs of the
day. But common sense says each should have been on its own radial with
the correct fuse.

Parent's house was built new in the 1930s. Originally, one 15 amp 2 pin
per room, each on its own radial.

--
*Real women don't have hot flashes, they have power surges.

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

On Monday, 6 January 2020 12:57:13 UTC, wrote:
On Monday, 6 January 2020 11:26:10 UTC, whisky-dave wrote:

What appliances do not need a fuse?

Aga cooker. Gas ascots. My electric toothbrush doesn't have a fuse, and niether does the charging station (that I know of) the 2 pin plug goes into an atapter
which does have a 3 amp fuse in it IIRC, same as with my shaver.

Are you sure the charging station doesn't have some form of internal
fuse?

I assume it does but we are talking about appliancies where the fuse can be replaced. AFAIK my toothbrush does NOT contain a fuse.
The charging station should have a fuse as that is the ONLY section connected to the mains supply and in accordence with UK electrical safety must contain some sort of fuse, whether it is current or temperature driven,
resetable or not I don't know, but it is most likely a non-servicable pat the
a user shouldn't replace.

The statement was what appliances NEED a fuse and not whether they have one or not, there is a differnce there too.


If an appliance uses an "inherently short-circuit proof" mains transformer
for its power supply, it does not need any kind of fuse - not even an
over-temperature fuse inside the transformer.

That's what I assumed as not everything needs a fuse, light bulbs tend not
to have fuses. Then you have the difficulty of deciding what an appliance is.
Which for most mean something in a specific range of products.
The vast majority of which will end up being plugged into the mains and that
item will have a 3 pin plug on the end.

I'm not sure if my hard wired cooker has any fuse(s) inside.
But once when I left one ring on by mistake it some how switched it's self off
after an hour or so.


I have designed such products and had them successfully tested by Intertek.

John

On Mon, 06 Jan 2020 13:42:06 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
Scott wrote:
In the days of radial 5 and 15 amp circuits, the fuse was in the CU. And a
15 amp socket would often have an adaptor. With no fuse.

Interesting question: were the 15 amp sockets and 5 amp sockets on
different circuits or mixed together?

In practice? Often mixed. In theory, you'd need to find the regs of the
day. But common sense says each should have been on its own radial with
the correct fuse.

Parent's house was built new in the 1930s. Originally, one 15 amp 2 pin
per room, each on its own radial.

Did every socket have its own connection to the fuse box or could
spurs be taken off the radial circuit?

On Monday, 6 January 2020 14:17:30 UTC, whisky-dave wrote:
On Monday, 6 January 2020 12:57:13 UTC, wrote:
On Monday, 6 January 2020 11:26:10 UTC, whisky-dave wrote:

The statement was what appliances NEED a fuse and not whether they have one or not, there is a differnce there too.


If an appliance uses an "inherently short-circuit proof" mains transformer
for its power supply, it does not need any kind of fuse - not even an
over-temperature fuse inside the transformer.

That's what I assumed as not everything needs a fuse, light bulbs tend not
to have fuses. Then you have the difficulty of deciding what an appliance is.
Which for most mean something in a specific range of products.
The vast majority of which will end up being plugged into the mains and that
item will have a 3 pin plug on the end.

Filament lightbulbs have ballotini fuses
http://www.lamptech.co.uk/Documents/IN%20Fusing.htm


NT

On Monday, 6 January 2020 23:32:37 UTC, wrote:
On Monday, 6 January 2020 14:17:30 UTC, whisky-dave wrote:
On Monday, 6 January 2020 12:57:13 UTC, wrote:
On Monday, 6 January 2020 11:26:10 UTC, whisky-dave wrote:

The statement was what appliances NEED a fuse and not whether they have one or not, there is a differnce there too.


If an appliance uses an "inherently short-circuit proof" mains transformer
for its power supply, it does not need any kind of fuse - not even an
over-temperature fuse inside the transformer.

That's what I assumed as not everything needs a fuse, light bulbs tend not
to have fuses. Then you have the difficulty of deciding what an appliance is.
Which for most mean something in a specific range of products.
The vast majority of which will end up being plugged into the mains and that
item will have a 3 pin plug on the end.

Filament lightbulbs have ballotini fuses
http://www.lamptech.co.uk/Documents/IN%20Fusing.htm


NT

Bulbs are rarely refered to as appliances,
But as indicated the claim that 200 amps can flow
doesn't really mean much, as my fuse in my CU lighting circuit is 5 amp.
So what if 200 amps flows for 1 microsecond.
if 200 amps can flow though my lighting circuit then 200 amps can also
through through a IEC lead with a 13 amp fuse in it.

But that still misses the most important point, what is the point of the fuse ?
Is it to save the bulb (perhasp referred to as the appliance) or the household wiring ?

It's to protect the wiring just like the fuse in an IEC lead.
SO it's doing the same job as a fuse in a 3 pin plug.
It's just been moved that's all.

wrote:
On Monday, 6 January 2020 14:17:30 UTC, whisky-dave wrote:
On Monday, 6 January 2020 12:57:13 UTC, wrote:
On Monday, 6 January 2020 11:26:10 UTC, whisky-dave wrote:

The statement was what appliances NEED a fuse and not whether they
have one or not, there is a differnce there too.


If an appliance uses an "inherently short-circuit proof" mains transformer
for its power supply, it does not need any kind of fuse - not even an
over-temperature fuse inside the transformer.

That's what I assumed as not everything needs a fuse, light bulbs tend not
to have fuses. Then you have the difficulty of deciding what an appliance is.
Which for most mean something in a specific range of products.
The vast majority of which will end up being plugged into the mains and that
item will have a 3 pin plug on the end.

Filament lightbulbs have ballotini fuses
http://www.lamptech.co.uk/Documents/IN%20Fusing.htm


NT


Dont you mean €œalmost never have Ballotini fuses€�? Ive never seen one.
Admittedly its a while since Ive squinted closely at a filament bulb but
Ive just dissected one and no sign of a Ballotini fuse.

Indeed, if youd read the link youd posted youd see that a) theyre
expensive and b) reserved for lamps than cant accommodate the more normal
€œfuse wire€� type fuse in the stem.


Ballotini Fusing
This is the safest and most reliable fuse type - but also the most
expensive. The fuse wire is encapsulated in a small glass tube filled with
tiny glass beads called Ballotini, named after Potters Ballotini, the
Italian producer. Should a secondary arc form between the broken pieces of
fuse wire, its heat will melt the glass beads to form an electrically
insulating barrier which contains and rapidly quenches the arc. It is so
efficient that only one fuse is required, but on account of their higher
price they are generally employed only in the more expensive special lamps,
or decorative lamps which are too small to be able to accommodate two
sufficiently long bare fuses (e.g. candle and globe lamps).

Tim

--
Please don't feed the trolls

In article ,
The Natural Philosopher wrote:
On 29/12/2019 14:52, John Rumm wrote:

I appreciate that motors have a surge at the start. I believe a 50%
margin should be added generally (more for a motor).

Depends on the motor, inrush on some induction motors can be 9x nominal.

In general the better the motor efficiency the worse is the surge.

10x is easily achievable wioth 'good' motors.

cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Interesting take. Designing something so it works properly in practice
makes it pants?


-

--
*I feel like I'm diagonally parked in a parallel universe*

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

In article ,
Scott wrote:
On Mon, 06 Jan 2020 13:42:06 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
Scott wrote:
In the days of radial 5 and 15 amp circuits, the fuse was in the CU. And a
15 amp socket would often have an adaptor. With no fuse.

Interesting question: were the 15 amp sockets and 5 amp sockets on
different circuits or mixed together?

In practice? Often mixed. In theory, you'd need to find the regs of the
day. But common sense says each should have been on its own radial with
the correct fuse.

Parent's house was built new in the 1930s. Originally, one 15 amp 2 pin
per room, each on its own radial.

Did every socket have its own connection to the fuse box or could
spurs be taken off the radial circuit?

In practice, that's exactly what happened. Mostly a 5 amp or two added to
a 15 amp radial.

--
*Procrastinate now

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

In article ,
says...


Early colour TVs could have a high inrush current enough to blow a 13 amp
fuse, even when the quoted power consumption was well below 3kW. But not
the anti-surge type fitted to the TV.

Never had one that bad but one day, a couple of the apprentice
electricians were sent out to deliver a new colour set. They
came back saying it was dead.

On investigation, I found that being mindful of the high cost
of these sets they'd been ultra careful and fitted a 5A fuse -
which, of course, matched the rating of the mains lead.

However, at switch on, colour sets took a mighty gulp of power
to drive the degaussing coils to demagnetise the tube which
considerably exceeded 5A!

The original 13A fuse was refitted and everything worked.

Thinking back to those days, I can't recall a single 13A plug
anywhere being sold fitted with anything other than a 13A
fuse, irrespective of what they were going to be used for, so
how were the public expected to be educated to use the correct
fuse for the job?

It was several years after this event that I first spotted
plugs for sale with red (3A) and brown (13A) stickers and, of
all places (unless I'm mistaken) it was in Woolworths!

--

Terry

When all else fails, read the instructions.

On Tue, 7 Jan 2020 15:11:49 -0000, Terry Casey
wrote:

In article ,
says...


Early colour TVs could have a high inrush current enough to blow a 13 amp
fuse, even when the quoted power consumption was well below 3kW. But not
the anti-surge type fitted to the TV.

Never had one that bad but one day, a couple of the apprentice
electricians were sent out to deliver a new colour set. They
came back saying it was dead.

On investigation, I found that being mindful of the high cost
of these sets they'd been ultra careful and fitted a 5A fuse -
which, of course, matched the rating of the mains lead.

However, at switch on, colour sets took a mighty gulp of power
to drive the degaussing coils to demagnetise the tube which
considerably exceeded 5A!

The original 13A fuse was refitted and everything worked.

I had similar in my latest adventures. I fitted a 1A fuse (by
mistake) to a kitchen TV and it lasted a fraction of a second. I
upped it to 3A and it's fine (even though the plug states 5A).

On 07/01/2020 15:11, Terry Casey wrote:
In article ,
says...


Early colour TVs could have a high inrush current enough to blow a 13 amp
fuse, even when the quoted power consumption was well below 3kW. But not
the anti-surge type fitted to the TV.

Never had one that bad but one day, a couple of the apprentice
electricians were sent out to deliver a new colour set. They
came back saying it was dead.

On investigation, I found that being mindful of the high cost
of these sets they'd been ultra careful and fitted a 5A fuse -
which, of course, matched the rating of the mains lead.

However, at switch on, colour sets took a mighty gulp of power
to drive the degaussing coils to demagnetise the tube which
considerably exceeded 5A!

The original 13A fuse was refitted and everything worked.

Thinking back to those days, I can't recall a single 13A plug
anywhere being sold fitted with anything other than a 13A
fuse, irrespective of what they were going to be used for, so
how were the public expected to be educated to use the correct
fuse for the job?

It was several years after this event that I first spotted
plugs for sale with red (3A) and brown (13A) stickers and, of
all places (unless I'm mistaken) it was in Woolworths!

Very likely Woolworths, they stocked all sorts of handy bits and pieces.

Funnily enough, my first (temporary) job after graduating in 1990 was
using AutoCad 2.6, to draw up the Woolworths packaging designs,
including the diagrams and text on the back, for Volex plugs, sockets,
switches and the like. It brought in some income for three months while
I looked for a proper job.

SteveW

In article 9c74a21d-9a2e-4796-8e24-d1aa341244c6
@googlegroups.com, says...

But there;s nothing stoping an idiot cutting up a nail or
putting in paper clip or anything else in the fuse holder.


The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

--

Terry

When all else fails, read the instructions.

On Tuesday, 7 January 2020 15:11:52 UTC, Terry Casey wrote:
In article ,



Thinking back to those days, I can't recall a single 13A plug
anywhere being sold fitted with anything other than a 13A
fuse, irrespective of what they were going to be used for,

which is why 13 amp was the best fuse to use, if you wanted your 'appliance'
back up and working again ASAP.


so
how were the public expected to be educated to use the correct
fuse for the job?

They weren't genarlly speaking but there were charts that were sold with fuse packs. Well I saw one in my fathers tobacco tin that contained spare fuses.
There' weren;t as many products about then either.



It was several years after this event that I first spotted
plugs for sale with red (3A) and brown (13A) stickers and, of
all places (unless I'm mistaken) it was in Woolworths!

I remmeber in about 1977, I was asked to check all the plugs and fuses
in teh school science labs to check connections and that bthe right fuse was installed, I was provided with a list of what fuse to put in which type of product. Then the standards seemed to be 3, 5 or 13 amp, that was it.


Now it;s just a 3amp or 13amp sand no calcualting is required or should be done.

https://www.electricalsafetyfirst.or...ugs-and-fuses/

Manufacturers have now standardised plug fuse ratings to be either 3A or 13A. However, 5 Amp fuses are still used in some older equipment and are available to buy.

I'm not sure that of you put a 1 amp fuse in a stand with a 15W light would fail
a PAT test, or any other valuse other than 3 amp but I do have a number of IEC leads with 5amp fuses that passed their PAT in 2018.

Anytime we replace such a fuse it must be with the same type IIRC and the lead must be PAT tested (with a machine) before being put in use.

As we've cherged somewhere bewteen £1.19 and £1.39 per test I tend to
dump the lead by cutting off the plug and removing the fuse and it's retainer,
and use a new lead. I have about 100-200 spare.
Which also get tested even if they haven't been used.

On Tuesday, 7 January 2020 16:13:12 UTC, Terry Casey wrote:
In article 9c74a21d-9a2e-4796-8e24-d1aa341244c6
@googlegroups.com, says...

But there;s nothing stoping an idiot cutting up a nail or
putting in paper clip or anything else in the fuse holder.


The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

Does that silver paper conduct enough ?
Have to get one from a friend to try, my cat also likes that paper screwed up
and plays with it more than she does actual toys I've bought.

She also like the aluminium foil rolled into a ball, not sure why but at a guess
is the crincle sound and perhaps the reflections.

In article 0b7058f1-2bb9-401d-999e-ac584814c973
@googlegroups.com, says...

On Tuesday, 7 January 2020 16:13:12 UTC, Terry Casey wrote:

The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

Does that silver paper conduct enough ?

It certainly did in the 60s!

Favourite substitute for pop groups (usually without clearing
the fault first!)

--

Terry

When all else fails, read the instructions.

On Wednesday, 8 January 2020 14:10:30 UTC, Terry Casey wrote:
In article 0b7058f1-2bb9-401d-999e-ac584814c973
@googlegroups.com, says...

On Tuesday, 7 January 2020 16:13:12 UTC, Terry Casey wrote:

The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

Does that silver paper conduct enough ?

It certainly did in the 60s!

I just measure some from a packet of silk cut.

0.019 ohms between two points 1 inch apart about the lenght of a mains fuse.

I didn't think this sort of silver paper conducted so much,
I'll never have to buy a fuse again.

All measured at about 1 inch spacing
Silver paper from a viscount chocolate bisciut 0.012 R
Aluminium foil at 0.009 R
a 13 amp fuse. at 0.002 R.

(Test Leads shorted together 0.0126 R )

measured using a LCR meter Agilent U1731C



Favourite substitute for pop groups (usually without clearing
the fault first!)

Wonder how I can test the actual fusing current.

In article ,
Terry Casey wrote:
Early colour TVs could have a high inrush current enough to blow a 13
amp fuse, even when the quoted power consumption was well below 3kW.
But not the anti-surge type fitted to the TV.

Never had one that bad but one day, a couple of the apprentice
electricians were sent out to deliver a new colour set. They came back
saying it was dead.

On investigation, I found that being mindful of the high cost
of these sets they'd been ultra careful and fitted a 5A fuse -
which, of course, matched the rating of the mains lead.

However, at switch on, colour sets took a mighty gulp of power
to drive the degaussing coils to demagnetise the tube which
considerably exceeded 5A!

The original 13A fuse was refitted and everything worked.

That's pretty well what I was saying. ;-)

Set in question was a G6 Philips - hybrid, using valves on the output
stages. And the high inrush caused even a 13 amp fuse to fail after some
time. New one gave the same sort of life.

--
*On the seventh day He brewed beer *

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

In article ,
Fredxx wrote:
cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Car window winders are an especially bad example. They use load sensors
to ensure nothing is trapped, such as a child's arm, in the window.

Interesting. Never come across that. How do they work? And why fit a motor
so powerful it could do an arm damage? Most are easily stopped by hand.

--
*Depression is merely anger without enthusiasm *

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

On 08/01/2020 17:05, Dave Plowman (News) wrote:
In article ,
Fredxx wrote:
cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Car window winders are an especially bad example. They use load sensors
to ensure nothing is trapped, such as a child's arm, in the window.

Interesting. Never come across that. How do they work? And why fit a motor
so powerful it could do an arm damage? Most are easily stopped by hand.

An arm is not a problem, a neck is. It takes very little pressure to
stop either breathing or cut off blood to the brain. Children have died
that way, which is why load sensors were added.

A reasonably powerful motor is required, because otherwise you could be
unable to open it (or worse, close it) as the car ages and the mechanism
stiffens or when there is ice on the doors. A 90's Cavalier used to have
an override button on the centre console to temporarily disable the load
sensors for this. These days repressing the button a few times does the
same for some vehicles.

It is likely that the reason that you can easily stop a window, is
because it is sensing too much load and stopping - some actually reverse
a short distance as well.

SteveW

On Wed, 08 Jan 2020 07:38:47 -0800, whisky-dave wrote:

I just measure some from a packet of silk cut.

0.019 ohms between two points 1 inch apart about the lenght of a mains
fuse.

I didn't think this sort of silver paper conducted so much,
I'll never have to buy a fuse again.

All measured at about 1 inch spacing Silver paper from a viscount
chocolate bisciut 0.012 R Aluminium foil at 0.009 R a 13 amp fuse. at
0.002 R.

What was the 'width' of the paper? Just enough to roll round the fuse?

(Test Leads shorted together 0.0126 R )

Wot, no Kelvin clips in your lab?

measured using a LCR meter Agilent U1731C

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

In article ,
Steve Walker wrote:
On 08/01/2020 17:05, Dave Plowman (News) wrote:
In article ,
Fredxx wrote:
cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Car window winders are an especially bad example. They use load sensors
to ensure nothing is trapped, such as a child's arm, in the window.

Interesting. Never come across that. How do they work? And why fit a motor
so powerful it could do an arm damage? Most are easily stopped by hand.

An arm is not a problem, a neck is. It takes very little pressure to
stop either breathing or cut off blood to the brain. Children have died
that way, which is why load sensors were added.

When were load sensors added? Given electric windows have been around for
a long long time, if not so long on UK cars.

A reasonably powerful motor is required, because otherwise you could be
unable to open it (or worse, close it) as the car ages and the mechanism
stiffens or when there is ice on the doors. A 90's Cavalier used to have
an override button on the centre console to temporarily disable the load
sensors for this. These days repressing the button a few times does the
same for some vehicles.

So how does the motor know if it is friction or ice or whatever rather
than a child's neck?

It is likely that the reason that you can easily stop a window, is
because it is sensing too much load and stopping - some actually reverse
a short distance as well.

Early Rolls Royce windows stopped just short of closed. You had to press a
second button to close it fully. To avoid trapped fingers. That was so
inconvenient it was discontinued.

SteveW

--
*Xerox and Wurlitzer will merge to market reproductive organs.

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

On Tuesday, 7 January 2020 11:26:46 UTC, whisky-dave wrote:
On Monday, 6 January 2020 23:32:37 UTC, tabby wrote:
On Monday, 6 January 2020 14:17:30 UTC, whisky-dave wrote:
On Monday, 6 January 2020 12:57:13 UTC, wrote:
On Monday, 6 January 2020 11:26:10 UTC, whisky-dave wrote:

The statement was what appliances NEED a fuse and not whether they have one or not, there is a differnce there too.


If an appliance uses an "inherently short-circuit proof" mains transformer
for its power supply, it does not need any kind of fuse - not even an
over-temperature fuse inside the transformer.

That's what I assumed as not everything needs a fuse, light bulbs tend not
to have fuses. Then you have the difficulty of deciding what an appliance is.
Which for most mean something in a specific range of products.
The vast majority of which will end up being plugged into the mains and that
item will have a 3 pin plug on the end.

Filament lightbulbs have ballotini fuses
http://www.lamptech.co.uk/Documents/IN%20Fusing.htm


NT

Bulbs are rarely refered to as appliances,

luminaires are

But as indicated the claim that 200 amps can flow
doesn't really mean much, as my fuse in my CU lighting circuit is 5 amp.

It surely does.

So what if 200 amps flows for 1 microsecond.

It means exploding glass is a risk.

if 200 amps can flow though my lighting circuit then 200 amps can also
through through a IEC lead with a 13 amp fuse in it.

Thousands of amps can flow through such leads.

But that still misses the most important point, what is the point of the fuse ?
Is it to save the bulb (perhasp referred to as the appliance) or the household wiring ?

It's to protect the wiring just like the fuse in an IEC lead.
SO it's doing the same job as a fuse in a 3 pin plug.

no, it's to prevent the lightbulb exploding.

It's just been moved that's all.


NT

On Tuesday, 7 January 2020 12:13:05 UTC, Tim+ wrote:
tabbypurr wrote:
On Monday, 6 January 2020 14:17:30 UTC, whisky-dave wrote:
On Monday, 6 January 2020 12:57:13 UTC, wrote:
On Monday, 6 January 2020 11:26:10 UTC, whisky-dave wrote:

The statement was what appliances NEED a fuse and not whether they
have one or not, there is a differnce there too.


If an appliance uses an "inherently short-circuit proof" mains transformer
for its power supply, it does not need any kind of fuse - not even an
over-temperature fuse inside the transformer.

That's what I assumed as not everything needs a fuse, light bulbs tend not
to have fuses. Then you have the difficulty of deciding what an appliance is.
Which for most mean something in a specific range of products.
The vast majority of which will end up being plugged into the mains and that
item will have a 3 pin plug on the end.

Filament lightbulbs have ballotini fuses
http://www.lamptech.co.uk/Documents/IN%20Fusing.htm


NT


Dont you mean €œalmost never have Ballotini fuses€�? Ive never seen one.
Admittedly its a while since Ive squinted closely at a filament bulb but
Ive just dissected one and no sign of a Ballotini fuse.

I've seen many

Indeed, if youd read the link youd posted

I did

youd see that a) theyre
expensive

they aren't, they just cost more than a bit of thin wire

and b) reserved for lamps than cant accommodate the more normal
€œfuse wire€� type fuse in the stem.

Some things are opinion, some things change over time. Yes of course there are lamps with cheaper fusing, and as the article says lamps with no fusing..


Ballotini Fusing
This is the safest and most reliable fuse type - but also the most
expensive. The fuse wire is encapsulated in a small glass tube filled with
tiny glass beads called Ballotini, named after Potters Ballotini, the
Italian producer. Should a secondary arc form between the broken pieces of
fuse wire, its heat will melt the glass beads to form an electrically
insulating barrier which contains and rapidly quenches the arc. It is so
efficient that only one fuse is required, but on account of their higher
price they are generally employed only in the more expensive special lamps,
or decorative lamps which are too small to be able to accommodate two
sufficiently long bare fuses (e.g. candle and globe lamps).

Tim

You may have noticed that candle and globe lamps are often not expensive.


NT

On Tuesday, 7 January 2020 15:11:52 UTC, Terry Casey wrote:
In article ,
says...


Early colour TVs could have a high inrush current enough to blow a 13 amp
fuse, even when the quoted power consumption was well below 3kW. But not
the anti-surge type fitted to the TV.

Never had one that bad but one day, a couple of the apprentice
electricians were sent out to deliver a new colour set. They
came back saying it was dead.

On investigation, I found that being mindful of the high cost
of these sets they'd been ultra careful and fitted a 5A fuse -
which, of course, matched the rating of the mains lead.

However, at switch on, colour sets took a mighty gulp of power
to drive the degaussing coils to demagnetise the tube which
considerably exceeded 5A!

The original 13A fuse was refitted and everything worked.

Thinking back to those days, I can't recall a single 13A plug
anywhere being sold fitted with anything other than a 13A
fuse, irrespective of what they were going to be used for, so
how were the public expected to be educated to use the correct
fuse for the job?

It was several years after this event that I first spotted
plugs for sale with red (3A) and brown (13A) stickers and, of
all places (unless I'm mistaken) it was in Woolworths!

My memory is fuzzy on this but weren't there tv ads saying when to use 3 vs 13A? I also remember seeing lists, but I don't recall where


NT

On 08/01/2020 17:05, Dave Plowman (News) wrote:
In article ,
Fredxx wrote:
cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Car window winders are an especially bad example. They use load sensors
to ensure nothing is trapped, such as a child's arm, in the window.

Interesting. Never come across that. How do they work? And why fit a motor
so powerful it could do an arm damage? Most are easily stopped by hand.

I thought that nowadays you have to hold the button down to close the
power window. Only opening goes all the way down with one press.

--
Max Demian

On Tuesday, 7 January 2020 16:13:12 UTC, Terry Casey wrote:
In article 9c74a21d-9a2e-4796-8e24-d1aa341244c6
@googlegroups.com, says...

But there;s nothing stoping an idiot cutting up a nail or
putting in paper clip or anything else in the fuse holder.


The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

There used to be a lot of creative workarounds, some with zero regard for safety.


NT

On Wednesday, 8 January 2020 15:38:51 UTC, whisky-dave wrote:
On Wednesday, 8 January 2020 14:10:30 UTC, Terry Casey wrote:
In article 0b7058f1-2bb9-401d-999e-ac584814c973
@googlegroups.com, says...

On Tuesday, 7 January 2020 16:13:12 UTC, Terry Casey wrote:

The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

Does that silver paper conduct enough ?

It certainly did in the 60s!

I just measure some from a packet of silk cut.

0.019 ohms between two points 1 inch apart about the lenght of a mains fuse.

I didn't think this sort of silver paper conducted so much,
I'll never have to buy a fuse again.

All measured at about 1 inch spacing
Silver paper from a viscount chocolate bisciut 0.012 R
Aluminium foil at 0.009 R
a 13 amp fuse. at 0.002 R.

(Test Leads shorted together 0.0126 R )

measured using a LCR meter Agilent U1731C

Did you put prongs onto the foil or wrap it round an open fuse in a mains plug then measure? The latter would give lower R


NT

On 08/01/2020 18:58, Dave Plowman (News) wrote:
In article ,
Steve Walker wrote:
On 08/01/2020 17:05, Dave Plowman (News) wrote:
In article ,
Fredxx wrote:
cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Car window winders are an especially bad example. They use load sensors
to ensure nothing is trapped, such as a child's arm, in the window.

Interesting. Never come across that. How do they work? And why fit a motor
so powerful it could do an arm damage? Most are easily stopped by hand.

An arm is not a problem, a neck is. It takes very little pressure to
stop either breathing or cut off blood to the brain. Children have died
that way, which is why load sensors were added.

When were load sensors added? Given electric windows have been around for
a long long time, if not so long on UK cars.

Back in the early '90s I think.

A reasonably powerful motor is required, because otherwise you could be
unable to open it (or worse, close it) as the car ages and the mechanism
stiffens or when there is ice on the doors. A 90's Cavalier used to have
an override button on the centre console to temporarily disable the load
sensors for this. These days repressing the button a few times does the
same for some vehicles.

So how does the motor know if it is friction or ice or whatever rather
than a child's neck?

Like I said, at least one of the early overrides was by a separate
button, but later repeated pressing would do it. The system doesn't know
what's in the way, but it does know that you have realised that the load
sensor has stopped the window and you have taken further action to
override it.

It is likely that the reason that you can easily stop a window, is
because it is sensing too much load and stopping - some actually reverse
a short distance as well.

Early Rolls Royce windows stopped just short of closed. You had to press a
second button to close it fully. To avoid trapped fingers. That was so
inconvenient it was discontinued.

Yes. I can see that would be an annoyance.

SteveW

On 08/01/2020 23:05, Max Demian wrote:
On 08/01/2020 17:05, Dave Plowman (News) wrote:
In article ,
Â*Â*Â* Fredxx wrote:
cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Car window winders are an especially bad example. They use load sensors
to ensure nothing is trapped, such as a child's arm, in the window.

Interesting. Never come across that. How do they work? And why fit a
motor
so powerful it could do an arm damage? Most are easily stopped by hand.

I thought that nowadays you have to hold the button down to close the
power window. Only opening goes all the way down with one press.

No, my Zafira B has auto closing on all windows.

SteveW

On 08/01/2020 23:05, Max Demian wrote:
On 08/01/2020 17:05, Dave Plowman (News) wrote:
In article ,
Â*Â*Â* Fredxx wrote:
cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Car window winders are an especially bad example. They use load sensors
to ensure nothing is trapped, such as a child's arm, in the window.

Interesting. Never come across that. How do they work? And why fit a
motor
so powerful it could do an arm damage? Most are easily stopped by hand.

I thought that nowadays you have to hold the button down to close the
power window. Only opening goes all the way down with one press.

Depends on the car.

My latest is auto all the way in both directions

--
Climate Change: Socialism wearing a lab coat.

On Wednesday, 8 January 2020 18:01:25 UTC, Bob Eager wrote:
On Wed, 08 Jan 2020 07:38:47 -0800, whisky-dave wrote:

I just measure some from a packet of silk cut.

0.019 ohms between two points 1 inch apart about the lenght of a mains
fuse.

I didn't think this sort of silver paper conducted so much,
I'll never have to buy a fuse again.

All measured at about 1 inch spacing Silver paper from a viscount
chocolate bisciut 0.012 R Aluminium foil at 0.009 R a 13 amp fuse. at
0.002 R.

What was the 'width' of the paper? Just enough to roll round the fuse?

about 1 1/4 inches for each test.
I was just interested in the resiatnce rather than the other (can't remmeber what it's called) but I have been asked in the past for a resestivity meter,
which is what yuo call it if your measuring the resistance of a cube of something from one surface to another.


(Test Leads shorted together 0.0126 R )

Wot, no Kelvin clips in your lab?

yes just one pair for special use only with our

https://onecall.farnell.com/rohde-sc...ecall%2Fsearch

as we only have one of these whereas we have 6 of the other LCR meters that we allow students to use unsupervised.

In reality I couldn't be bothered getting the kelin leads from the padlocked cupboard.

I also prefer to use the same kit as the students, because it means I understand
better what they have to use and how.



measured using a LCR meter Agilent U1731C

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On Wednesday, 8 January 2020 22:57:25 UTC, wrote:
On Tuesday, 7 January 2020 11:26:46 UTC, whisky-dave wrote:
On Monday, 6 January 2020 23:32:37 UTC, tabby wrote:
On Monday, 6 January 2020 14:17:30 UTC, whisky-dave wrote:
On Monday, 6 January 2020 12:57:13 UTC, wrote:
On Monday, 6 January 2020 11:26:10 UTC, whisky-dave wrote:

The statement was what appliances NEED a fuse and not whether they have one or not, there is a differnce there too.


If an appliance uses an "inherently short-circuit proof" mains transformer
for its power supply, it does not need any kind of fuse - not even an
over-temperature fuse inside the transformer.

That's what I assumed as not everything needs a fuse, light bulbs tend not
to have fuses. Then you have the difficulty of deciding what an appliance is.
Which for most mean something in a specific range of products.
The vast majority of which will end up being plugged into the mains and that
item will have a 3 pin plug on the end.

Filament lightbulbs have ballotini fuses
http://www.lamptech.co.uk/Documents/IN%20Fusing.htm


NT

Bulbs are rarely refered to as appliances,

luminaires are

Not by those that know what they are talking about.

Luminaires are the complete lighting unit.
So yuo can have a luminaires with 6 bulbs but NOT a bulb with 6 luminaires.




But as indicated the claim that 200 amps can flow
doesn't really mean much, as my fuse in my CU lighting circuit is 5 amp.

It surely does.

So what if 200 amps flows for 1 microsecond.

It means exploding glass is a risk.

Which won't affect my CU.

I've had 3 CFC's blow my 5 amp fuse in the lighing ring,
and the lights went out with a bang.
won't be buying them again, 3 for a fiver not worth the hassle.






if 200 amps can flow though my lighting circuit then 200 amps can also
through through a IEC lead with a 13 amp fuse in it.

Thousands of amps can flow through such leads.

I know it can, but it doesn;t really happen in reality for enough time to worry about.

Maybe that's why I have a 500 amp fuse here.


But that still misses the most important point, what is the point of the fuse ?
Is it to save the bulb (perhasp referred to as the appliance) or the household wiring ?

It's to protect the wiring just like the fuse in an IEC lead.
SO it's doing the same job as a fuse in a 3 pin plug.

no, it's to prevent the lightbulb exploding.

yes I lnow but not every lightbulb, if that was the case why not have such a fuse in the CU.


It's just been moved that's all.


NT

On Wednesday, 8 January 2020 23:10:33 UTC, wrote:
On Wednesday, 8 January 2020 15:38:51 UTC, whisky-dave wrote:
On Wednesday, 8 January 2020 14:10:30 UTC, Terry Casey wrote:
In article 0b7058f1-2bb9-401d-999e-ac584814c973
@googlegroups.com, says...

On Tuesday, 7 January 2020 16:13:12 UTC, Terry Casey wrote:

The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

Does that silver paper conduct enough ?

It certainly did in the 60s!

I just measure some from a packet of silk cut.

0.019 ohms between two points 1 inch apart about the lenght of a mains fuse.

I didn't think this sort of silver paper conducted so much,
I'll never have to buy a fuse again.

All measured at about 1 inch spacing
Silver paper from a viscount chocolate bisciut 0.012 R
Aluminium foil at 0.009 R
a 13 amp fuse. at 0.002 R.

(Test Leads shorted together 0.0126 R )

measured using a LCR meter Agilent U1731C

Did you put prongs onto the foil or wrap it round an open fuse in a mains plug then measure? The latter would give lower R

My first test I used our standard meter probes that were suppl.ied woith our default~£30 meters,


when I realised the resistance was 1R I went and got the
Agilent U1731C meter and used the supplied lead with small croc clips
which looks like this

https://uk.rs-online.com/web/p/lcr-m...ories/7118054/
I put the croc clips to the flat foil(s)

When measuring the fuse I clipped the croc clips around the end of the fuse caps.



NT

In article ,
Steve Walker wrote:
I thought that nowadays you have to hold the button down to close the
power window. Only opening goes all the way down with one press.

No, my Zafira B has auto closing on all windows.

So did my last three cars.

--
*Never slap a man who's chewing tobacco *

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

On Thursday, 9 January 2020 12:41:56 UTC, whisky-dave wrote:
On Wednesday, 8 January 2020 22:57:25 UTC, tabby wrote:
On Tuesday, 7 January 2020 11:26:46 UTC, whisky-dave wrote:
On Monday, 6 January 2020 23:32:37 UTC, tabby wrote:

Bulbs are rarely refered to as appliances,

luminaires are

Not by those that know what they are talking about.

Luminaires are the complete lighting unit.
So yuo can have a luminaires with 6 bulbs but NOT a bulb with 6 luminaires.

heh


But as indicated the claim that 200 amps can flow
doesn't really mean much, as my fuse in my CU lighting circuit is 5 amp.

It surely does.

So what if 200 amps flows for 1 microsecond.

It means exploding glass is a risk.

Which won't affect my CU.

Not much. Shouldn't affect your record collection either.


I've had 3 CFC's blow my 5 amp fuse in the lighing ring,
and the lights went out with a bang.
won't be buying them again, 3 for a fiver not worth the hassle.

most of us won't be buying CFLs again. It's 2020.


if 200 amps can flow though my lighting circuit then 200 amps can also
through through a IEC lead with a 13 amp fuse in it.

Thousands of amps can flow through such leads.

I know it can, but it doesn;t really happen in reality for enough time to worry about.

Of course it does, that's why CU MCBs & incomer fuses have the breaking capacity they do.


Maybe that's why I have a 500 amp fuse here.


But that still misses the most important point, what is the point of the fuse ?
Is it to save the bulb (perhasp referred to as the appliance) or the household wiring ?

It's to protect the wiring just like the fuse in an IEC lead.
SO it's doing the same job as a fuse in a 3 pin plug.

no, it's to prevent the lightbulb exploding.

yes I lnow but not every lightbulb, if that was the case why not have such a fuse in the CU.

there is a fuse in the CU, or an MCB.


NT

On Thursday, 9 January 2020 13:14:57 UTC, whisky-dave wrote:
On Wednesday, 8 January 2020 23:10:33 UTC, tabby wrote:
On Wednesday, 8 January 2020 15:38:51 UTC, whisky-dave wrote:
On Wednesday, 8 January 2020 14:10:30 UTC, Terry Casey wrote:
In article 0b7058f1-2bb9-401d-999e-ac584814c973
@googlegroups.com, says...

On Tuesday, 7 January 2020 16:13:12 UTC, Terry Casey wrote:

The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

Does that silver paper conduct enough ?

It certainly did in the 60s!

I just measure some from a packet of silk cut.

0.019 ohms between two points 1 inch apart about the lenght of a mains fuse.

I didn't think this sort of silver paper conducted so much,
I'll never have to buy a fuse again.

All measured at about 1 inch spacing
Silver paper from a viscount chocolate bisciut 0.012 R
Aluminium foil at 0.009 R
a 13 amp fuse. at 0.002 R.

(Test Leads shorted together 0.0126 R )

measured using a LCR meter Agilent U1731C

Did you put prongs onto the foil or wrap it round an open fuse in a mains plug then measure? The latter would give lower R

My first test I used our standard meter probes that were suppl.ied woith our default~£30 meters,


when I realised the resistance was 1R I went and got the
Agilent U1731C meter and used the supplied lead with small croc clips
which looks like this

https://uk.rs-online.com/web/p/lcr-m...ories/7118054/
I put the croc clips to the flat foil(s)

When measuring the fuse I clipped the croc clips around the end of the fuse caps.



NT

If you ever get round to wrapping a dead fuse with the foil paper & fitting it into a plug you'll get lower R readings.


NT

On Thursday, 9 January 2020 18:10:09 UTC, wrote:
On Thursday, 9 January 2020 13:14:57 UTC, whisky-dave wrote:
On Wednesday, 8 January 2020 23:10:33 UTC, tabby wrote:
On Wednesday, 8 January 2020 15:38:51 UTC, whisky-dave wrote:
On Wednesday, 8 January 2020 14:10:30 UTC, Terry Casey wrote:
In article 0b7058f1-2bb9-401d-999e-ac584814c973
@googlegroups.com, says...

On Tuesday, 7 January 2020 16:13:12 UTC, Terry Casey wrote:

The traditional method is silver paper from a cigarette packet
wrapped round the dead fuse. Perfect fit and lasts forever!

Does that silver paper conduct enough ?

It certainly did in the 60s!

I just measure some from a packet of silk cut.

0.019 ohms between two points 1 inch apart about the lenght of a mains fuse.

I didn't think this sort of silver paper conducted so much,
I'll never have to buy a fuse again.

All measured at about 1 inch spacing
Silver paper from a viscount chocolate bisciut 0.012 R
Aluminium foil at 0.009 R
a 13 amp fuse. at 0.002 R.

(Test Leads shorted together 0.0126 R )

measured using a LCR meter Agilent U1731C

Did you put prongs onto the foil or wrap it round an open fuse in a mains plug then measure? The latter would give lower R

My first test I used our standard meter probes that were suppl.ied woith our default~£30 meters,


when I realised the resistance was 1R I went and got the
Agilent U1731C meter and used the supplied lead with small croc clips
which looks like this

https://uk.rs-online.com/web/p/lcr-m...ories/7118054/
I put the croc clips to the flat foil(s)

When measuring the fuse I clipped the croc clips around the end of the fuse caps.



NT

If you ever get round to wrapping a dead fuse with the foil paper & fitting it into a plug you'll get lower R readings.

Of course but that low reading is only true if/when testing at low voltage and current. The foil is only on one side too. I do not think that this foil paper could pass 13 amps.




NT