I need to replace a PSU fuse in an LCD monitor. The open fuse is
ceramic, 5 x 20 mm, and marked "T3.15AH250V", with no obvious spacing
between the various markings. I understand the speed rating (T) and the
voltage (250V), but I'm unclear on the amperage. Is it 3.15 amps, .15
amps, or 15 amps? Did some searching, but all I can find are pages
trying to sell fuses, not any giving how to read the ratings.

TIA

Dan

On 10/17/2013 4:55 PM, Dan wrote:
I need to replace a PSU fuse in an LCD monitor. The open fuse is
ceramic, 5 x 20 mm, and marked "T3.15AH250V", with no obvious spacing
between the various markings. I understand the speed rating (T) and the
voltage (250V), but I'm unclear on the amperage. Is it 3.15 amps, .15
amps, or 15 amps? Did some searching, but all I can find are pages
trying to sell fuses, not any giving how to read the ratings.

TIA

Dan
Google doesn't seem to have any trouble finding it.
First hit.
Assume you fixed what blew it.

"Dan" wrote in message
eb.com...
I need to replace a PSU fuse in an LCD monitor. The open fuse is
ceramic, 5 x 20 mm, and marked "T3.15AH250V", with no obvious spacing
between the various markings. I understand the speed rating (T) and the
voltage (250V), but I'm unclear on the amperage. Is it 3.15 amps, .15
amps, or 15 amps? Did some searching, but all I can find are pages trying
to sell fuses, not any giving how to read the ratings.

TIA

Dan


This is an absolutely bog standard fuse size. It is 'T' rated, and 3.15 amps
nominal carrying capacity. That is a very common value and fuse type
(ceramic bodied) for the front end fuse in a typical LCD TV switch-mode
power supply. It is important that it is only replaced with a ceramic type,
as faults in this area can cause a glass fuse to explode. Which brings me to
why you are replacing this fuse. It is quite unusual for the fuse in this
position to fail for no reason. You will normally find that the PSU has
suffered a major front-end failure, which may be something quite
straightforward like a faulty bridge, but more often than not, a fuse-blower
will have a short circuit switching element - usually a FET - and along with
this, it will have various short circuit diodes, open circuit resistors, and
often a blown supervisor IC ...

If that should turn out to be the case, there are 'repair kits' available on
the 'net for most common makes and models. These will contain a number of
components, all of which need to be replaced, whether the originals seem to
be faulty or not. 99% of the time, fitting such a kit results in a fix. A
degree of skill and knowledge beyond the level of simple fuse replacement,
is however required to do the job, as some parts may be surface mount.

Alternatively, replacement power supply boards are often available
remarkably cheaply.

So, bottom line, by all means try a replacement fuse first. You may be lucky
and get away with it. But be prepared for your new fuse to fail immediately
.... :-\

Arfa

On 10/17/2013 5:31 PM, mike wrote:
On 10/17/2013 4:55 PM, Dan wrote:
I need to replace a PSU fuse in an LCD monitor. The open fuse is
ceramic, 5 x 20 mm, and marked "T3.15AH250V", with no obvious spacing
between the various markings. I understand the speed rating (T) and the
voltage (250V), but I'm unclear on the amperage. Is it 3.15 amps, .15
amps, or 15 amps? Did some searching, but all I can find are pages
trying to sell fuses, not any giving how to read the ratings.

TIA

Dan
Google doesn't seem to have any trouble finding it.
First hit.
Assume you fixed what blew it.

No schmuck, the 1st hit is AMAZON selling the fuses. The next 99 on
that page are ALSO simply sellers.

Thanks so much for taking the time to be HELPFUL.

Arfa - Thanks for all the great info. What happened was my daughter
accidentally knocked the monitor on the floor when it was on, badly
banging the screen area. Oddly, it blew the ground fault interrupter
on that circuit, but also the internal fuse. The monitor is older,
probably not worth the more expensive repairs you suggest, but thanks
for passing on all the possibilities, I appreciate your help!

Dan

On 10/17/2013 5:37 PM, Arfa Daily wrote:


"Dan" wrote in message
eb.com...
I need to replace a PSU fuse in an LCD monitor. The open fuse is
ceramic, 5 x 20 mm, and marked "T3.15AH250V", with no obvious spacing
between the various markings. I understand the speed rating (T) and
the voltage (250V), but I'm unclear on the amperage. Is it 3.15 amps,
.15 amps, or 15 amps? Did some searching, but all I can find are pages
trying to sell fuses, not any giving how to read the ratings.

TIA

Dan


This is an absolutely bog standard fuse size. It is 'T' rated, and 3.15
amps nominal carrying capacity. That is a very common value and fuse
type (ceramic bodied) for the front end fuse in a typical LCD TV
switch-mode power supply. It is important that it is only replaced with
a ceramic type, as faults in this area can cause a glass fuse to
explode. Which brings me to why you are replacing this fuse. It is quite
unusual for the fuse in this position to fail for no reason. You will
normally find that the PSU has suffered a major front-end failure, which
may be something quite straightforward like a faulty bridge, but more
often than not, a fuse-blower will have a short circuit switching
element - usually a FET - and along with this, it will have various
short circuit diodes, open circuit resistors, and often a blown
supervisor IC ...

If that should turn out to be the case, there are 'repair kits'
available on the 'net for most common makes and models. These will
contain a number of components, all of which need to be replaced,
whether the originals seem to be faulty or not. 99% of the time, fitting
such a kit results in a fix. A degree of skill and knowledge beyond the
level of simple fuse replacement, is however required to do the job, as
some parts may be surface mount.

Alternatively, replacement power supply boards are often available
remarkably cheaply.

So, bottom line, by all means try a replacement fuse first. You may be
lucky and get away with it. But be prepared for your new fuse to fail
immediately ... :-\

Arfa

On 10/17/2013 5:56 PM, Dan wrote:
On 10/17/2013 5:31 PM, mike wrote:
On 10/17/2013 4:55 PM, Dan wrote:
I need to replace a PSU fuse in an LCD monitor. The open fuse is
ceramic, 5 x 20 mm, and marked "T3.15AH250V", with no obvious spacing
between the various markings. I understand the speed rating (T) and the
voltage (250V), but I'm unclear on the amperage. Is it 3.15 amps, .15
amps, or 15 amps? Did some searching, but all I can find are pages
trying to sell fuses, not any giving how to read the ratings.

TIA

Dan
Google doesn't seem to have any trouble finding it.
First hit.
Assume you fixed what blew it.

No schmuck, the 1st hit is AMAZON selling the fuses. The next 99 on
that page are ALSO simply sellers.

Thanks so much for taking the time to be HELPFUL.

Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V,
T3.15 H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm
(3/16" X 3/4"), 3.15A 250V, SLOW-blow (Time Delay)

And again with focus on the rating:
3.15A 250V

And again with just the amperage
3.15A
The A is for Amps.
That helpful enough for you?

"Arfa Daily"

So, bottom line, by all means try a replacement fuse first. You may be
lucky and get away with it. But be prepared for your new fuse to fail
immediately ... :-\

** Fuses cost money and I don't like to see them blow at switch on.

So my standard practice is to fit a new fuse and then connect the AC lead to
a Variac via a current meter ( true rms) and slowly wind up the voltage.
With a SMPS, the current reading should be small until it suddenly strikes
and runs at some voltage between 80V and 160V as shown on the Variac's dial.

If a current near to the fuse's rating appears at a low setting on the
Variac, then its game over.

In cases where the PCB has to be exposed to get at the fuse, visual
inspection for damage is the first step and then an old fashioned moving
coil multimeter on the low ohms range to check PSU diodes and the switching
transistor for shorts.

BTW:

Guitar amps regularly arrive with either no fuse or a glaringly wrong size
or type fuse - ie fast fuses in the AC.

However, the ones I really hate arrive with NO fuse cap in the holder.

Grrrrrr.........


..... Phil

"mike"

Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V, T3.15
H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm (3/16" X
3/4"), 3.15A 250V, SLOW-blow (Time Delay)


** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".



.... Phil

"Phil Allison" wrote in message ...


"mike"

Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V, T3.15
H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm (3/16" X
3/4"), 3.15A 250V, SLOW-blow (Time Delay)


** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".



.... Phil

How about T for tiny... like your dick!

Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V,
T3.15 H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm
(3/16" X 3/4"), 3.15A 250V, SLOW-blow (Time Delay)

Yeah, I saw that. It also says "You will receive 5 fuses and they can
be either of these marking: T3.15AH250V, T3.15A 250V, T3.15 H250V,
T3.15A 250V, T3.15H250V." Not being a fuse expert, I don't know that
these are all in fact interchangeable, and I thought perhaps it might be
better to clarify the rating numbers with someone who's NOT trying to
'sell me something'.


And again with focus on the rating:
3.15A 250V

And again with just the amperage
3.15A
The A is for Amps.
That helpful enough for you?


That's what I was looking for. That wasn't so hard, now was it? I
guess I'll leave it to you and your shrink to determine why you didn't
simply give that info to begin with, and instead felt the need to make a
total stranger feel stupid for asking a legitimate question in an
appropriate forum. My guess would be low self esteem, but check Amazon,
I bet they have a self-help book on it.

On Thursday, October 17, 2013 5:56:12 PM UTC-7, Dan wrote:
On 10/17/2013 5:31 PM, mike wrote:

On 10/17/2013 4:55 PM, Dan wrote:

I need to replace a PSU fuse in an LCD monitor. The open fuse is

ceramic, 5 x 20 mm, and marked "T3.15AH250V", with no obvious spacing

between the various markings. I understand the speed rating (T) and the

voltage (250V), but I'm unclear on the amperage. Is it 3.15 amps, .15

amps, or 15 amps? Did some searching, but all I can find are pages

trying to sell fuses, not any giving how to read the ratings.



TIA



Dan

Google doesn't seem to have any trouble finding it.

First hit.

Assume you fixed what blew it.



No schmuck, the 1st hit is AMAZON selling the fuses. The next 99 on

that page are ALSO simply sellers.



Thanks so much for taking the time to be HELPFUL.

A lot of nerve calling names when YOU'RE the who one can't read a fuse or even look it up. And what creative name will you have for me?

G²

On Fri, 18 Oct 2013 12:21:09 +1100 "Phil Allison"
wrote in Message id: :


"Arfa Daily"

So, bottom line, by all means try a replacement fuse first. You may be
lucky and get away with it. But be prepared for your new fuse to fail
immediately ... :-\

** Fuses cost money and I don't like to see them blow at switch on.

So my standard practice is to fit a new fuse and then connect the AC lead to
a Variac via a current meter ( true rms) and slowly wind up the voltage.
With a SMPS, the current reading should be small until it suddenly strikes
and runs at some voltage between 80V and 160V as shown on the Variac's dial.

If a current near to the fuse's rating appears at a low setting on the
Variac, then its game over.

In cases where the PCB has to be exposed to get at the fuse, visual
inspection for damage is the first step and then an old fashioned moving
coil multimeter on the low ohms range to check PSU diodes and the switching
transistor for shorts.

BTW:

Guitar amps regularly arrive with either no fuse or a glaringly wrong size
or type fuse - ie fast fuses in the AC.

However, the ones I really hate arrive with NO fuse cap in the holder.

Grrrrrr.........

Better yet if you can find one cheap, a Sencore PR570.
http://www.ebay.com/sch/Electrical-T...R40&_nkw=PR570
It has the capability to automatically trip and shut down it's AC output
if the current exceeds whatever setting you dial in. It doubles as an
isolation transformer and variable AC power supply as well. Got one of
these for $150 a year ago on Ebay, I can't count how many times I've used
it.

A Dim Bulb current limiter will protect better than a Variac. fyi.

http://www.kendrick-amplifiers.com/m...tegory_Code=04

On 10/17/2013 06:21 PM, Phil Allison wrote:
"Arfa Daily"

So, bottom line, by all means try a replacement fuse first. You may be
lucky and get away with it. But be prepared for your new fuse to fail
immediately ... :-\

** Fuses cost money and I don't like to see them blow at switch on.

So my standard practice is to fit a new fuse and then connect the AC lead to
a Variac via a current meter ( true rms) and slowly wind up the voltage.
With a SMPS, the current reading should be small until it suddenly strikes
and runs at some voltage between 80V and 160V as shown on the Variac's dial.

If a current near to the fuse's rating appears at a low setting on the
Variac, then its game over.

In cases where the PCB has to be exposed to get at the fuse, visual
inspection for damage is the first step and then an old fashioned moving
coil multimeter on the low ohms range to check PSU diodes and the switching
transistor for shorts.

BTW:

Guitar amps regularly arrive with either no fuse or a glaringly wrong size
or type fuse - ie fast fuses in the AC.

However, the ones I really hate arrive with NO fuse cap in the holder.

Grrrrrr.........


.... Phil

On 10/18/2013 02:51 AM, JW wrote:
On Fri, 18 Oct 2013 12:21:09 +1100 "Phil Allison"

http://pinyot.com/dimbulb/dim_bulb_tester.htm


Better yet if you can find one cheap, a Sencore PR570.
http://www.ebay.com/sch/Electrical-T...R40&_nkw=PR570
It has the capability to automatically trip and shut down it's AC output
if the current exceeds whatever setting you dial in. It doubles as an
isolation transformer and variable AC power supply as well. Got one of
these for $150 a year ago on Ebay, I can't count how many times I've used
it.

"dave" wrote in message
...
A Dim Bulb current limiter will protect better than a Variac. fyi.



$99?! I made one of them out of a piece of wood, a wall mount switch, a
wall mount switched 13A outlet, and a bulb holder, for thruppence ha'penny.

I use it a lot. In fact I used it today after a combo came in with a blown
fuse.


Gareth. (cheapskate)

"dave"

A Dim Bulb current limiter will protect better than a Variac. fyi.

http://www.kendrick-amplifiers.com/m...tegory_Code=04


** A Variac alone provides no protection.

But the method I outlined is vastly superior to the old light bulb trick.

Variac + true rms current meter + fuse (which can be a fast blow type).

There are far too many anomalies when a series lamp is fitted to the AC
supply.


.... Phil

"Phil Allison" wrote in message ...


"dave"

A Dim Bulb current limiter will protect better than a Variac. fyi.

http://www.kendrick-amplifiers.com/m...tegory_Code=04


** A Variac alone provides no protection.

But the method I outlined is vastly superior to the old light bulb trick.

Variac + true rms current meter + fuse (which can be a fast blow type).

There are far too many anomalies when a series lamp is fitted to the AC
supply.





I find the old lightbulb trick quick and easy, providing it is used in
appropriate circumstances.

Case in point being the bog standard small combo with the blown mains fuse I
used it on today, where it is a binary Yes there is a problem, or Not - the
fuse just blew.
And no harm done in the process, being as maximum mains current draw is 500
mA or so.
The amp will still run and make sound with the bulb in place.


I understand you can't use this techinique reliably on high power things
like Power Amps, cos they don't like undervoltage and will trip and
misbehave and do all sorts of weird stuff.
Here, I do use the variac in series with the bulb, just to see visually what
current is being drawn and how, and when.
And it is also sometimes useful to use the bulb as a soft start, then bypass
it, once you are happy the amp isn't going to explode.

Likewise I use the variac and bulb on SMPS's, again to visually and audibly
get an idea of whats happening and when.
You can hear when it kicks in, or shuts down, and that auditory information
is backed up by the behaviour of the bulb.



Horses for courses.


Gareth.

"Gareth Magennis"

I find the old lightbulb trick quick and easy, providing it is used in
appropriate circumstances.

Case in point being the bog standard small combo with the blown mains fuse
I used it on today, where it is a binary Yes there is a problem, or Not -
the fuse just blew.
And no harm done in the process, being as maximum mains current draw is
500 mA or so.

** A bulb that passes 0.5A rms when lit will pass 8A peak at switch on.

That is no soft start.


The amp will still run and make sound with the bulb in place.


** Then you have to remove it and all protection is lost.


I understand you can't use this techinique reliably on high power things
like Power Amps, cos they don't like undervoltage and will trip and
misbehave and do all sorts of weird stuff.

** A valve guitar amp of over 100 watts will not warm up and run with a 0.5A
bulb in the AC.


And it is also sometimes useful to use the bulb as a soft start, then
bypass it, once you are happy the amp isn't going to explode.


** A"soft start" is always provided when using a Variac.


Likewise I use the variac and bulb on SMPS's, again to visually and
audibly get an idea of whats happening and when.
You can hear when it kicks in, or shuts down, and that auditory
information is backed up by the behaviour of the bulb.

** You can stick with what you like and are used to.



.... Phil

On 10/18/2013 04:17 PM, Phil Allison wrote:


** A valve guitar amp of over 100 watts will not warm up and run with a 0.5A
bulb in the AC.


I routinely repair 100 Watt "valve" Marshalls, Fenders, Peaveys, Ampegs
(SLM), etc. and always use a 150 Watt bulb in series (and my 8 Ohm 100W
dummy load) until its time to check the bias. The one I use is clear (at
Home Depot fyi) and the orange glow on the filament is as sensitive an
indicator of current change as a panel meter. On very low idling only
part of the filament glows; play a power chord and the room lights up.

For a solid state amp up to about 75 Watts (no load) I use a clear 40
Watt oven bulb. Even on the bulb Marshall DSP works fine, the voltage
drop is low if the filament is cool.

Mine is a ceramic lamp socket, crudely spliced into a 15 Amp molded
extension cord, with a ground lift to accept 3 prongs, a switch, total
expenditure about $4.20. Oh yeah, the bulbs cost another tree fitty.

"Phil Allison" wrote in message
...

"Arfa Daily"

So, bottom line, by all means try a replacement fuse first. You may be
lucky and get away with it. But be prepared for your new fuse to fail
immediately ... :-\

** Fuses cost money and I don't like to see them blow at switch on.

So my standard practice is to fit a new fuse and then connect the AC lead
to a Variac via a current meter ( true rms) and slowly wind up the
voltage. With a SMPS, the current reading should be small until it
suddenly strikes and runs at some voltage between 80V and 160V as shown on
the Variac's dial.

If a current near to the fuse's rating appears at a low setting on the
Variac, then its game over.

In cases where the PCB has to be exposed to get at the fuse, visual
inspection for damage is the first step and then an old fashioned moving
coil multimeter on the low ohms range to check PSU diodes and the
switching transistor for shorts.

BTW:

Guitar amps regularly arrive with either no fuse or a glaringly wrong size
or type fuse - ie fast fuses in the AC.

However, the ones I really hate arrive with NO fuse cap in the holder.

Grrrrrr.........


.... Phil



All agreed. I too always bring a fuse-blower up on the variac, looking for
the same tell-tales as you. I didn't bother mentioning it, because I'm sure
the OP will not be familiar or equipped with such a workshop specific item.

Arfa

"Phil Allison" wrote in message
...

"dave"

A Dim Bulb current limiter will protect better than a Variac. fyi.

http://www.kendrick-amplifiers.com/m...tegory_Code=04


** A Variac alone provides no protection.

But the method I outlined is vastly superior to the old light bulb trick.

Variac + true rms current meter + fuse (which can be a fast blow type).

There are far too many anomalies when a series lamp is fitted to the AC
supply.


... Phil


Agreed. The dim bulb limiter is a bit of a catch-all largely designed for
production testing by people no necessarily skilled in electronics. A variac
used in the way you suggested, and the way that I too use mine, is just as
effective at avoiding burnups in a fuse-blower, whilst actually providing a
greater level of information about where to be looking for the problem. The
trick is that like an ESR meter, a degree of skill is required to use the
variac correctly (for this type of fault finding) and to interpret the
results obtained ...

Arfa

Dan wrote:
Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V,
T3.15 H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm
(3/16" X 3/4"), 3.15A 250V, SLOW-blow (Time Delay)

Yeah, I saw that. It also says "You will receive 5 fuses and they can
be either of these marking: T3.15AH250V, T3.15A 250V, T3.15 H250V,
T3.15A 250V, T3.15H250V." Not being a fuse expert, I don't know that
these are all in fact interchangeable, and I thought perhaps it might
be better to clarify the rating numbers with someone who's NOT trying
to 'sell me something'.


And again with focus on the rating:
3.15A 250V

And again with just the amperage
3.15A
The A is for Amps.
That helpful enough for you?


That's what I was looking for. That wasn't so hard, now was it? I
guess I'll leave it to you and your shrink to determine why you didn't
simply give that info to begin with, and instead felt the need to
make a total stranger feel stupid for asking a legitimate question in
an appropriate forum. My guess would be low self esteem, but check
Amazon, I bet they have a self-help book on it.

Is this the way YOU say thank you. Remind me no to respond to your posts.

On 10/19/2013 11:53 AM, Bob F wrote:
Dan wrote:
Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V,
T3.15 H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm
(3/16" X 3/4"), 3.15A 250V, SLOW-blow (Time Delay)

Yeah, I saw that. It also says "You will receive 5 fuses and they can
be either of these marking: T3.15AH250V, T3.15A 250V, T3.15 H250V,
T3.15A 250V, T3.15H250V." Not being a fuse expert, I don't know that
these are all in fact interchangeable, and I thought perhaps it might
be better to clarify the rating numbers with someone who's NOT trying
to 'sell me something'.


And again with focus on the rating:
3.15A 250V

And again with just the amperage
3.15A
The A is for Amps.
That helpful enough for you?


That's what I was looking for. That wasn't so hard, now was it? I
guess I'll leave it to you and your shrink to determine why you didn't
simply give that info to begin with, and instead felt the need to
make a total stranger feel stupid for asking a legitimate question in
an appropriate forum. My guess would be low self esteem, but check
Amazon, I bet they have a self-help book on it.

Is this the way YOU say thank you. Remind me no to respond to your posts.


Chill.
My bad, I forced the issue.
Blame me for my inciteful response.

"Arfa Daily"
"Phil Allison"
"Arfa Daily"

So, bottom line, by all means try a replacement fuse first. You may be
lucky and get away with it. But be prepared for your new fuse to fail
immediately ... :-\

** Fuses cost money and I don't like to see them blow at switch on.

So my standard practice is to fit a new fuse and then connect the AC lead
to a Variac via a current meter ( true rms) and slowly wind up the
voltage. With a SMPS, the current reading should be small until it
suddenly strikes and runs at some voltage between 80V and 160V as shown
on the Variac's dial.

If a current near to the fuse's rating appears at a low setting on the
Variac, then its game over.


All agreed. I too always bring a fuse-blower up on the variac, looking for
the same tell-tales as you.


** OK, my test set up is used with ALL items for repair.

The AC current meter uses a Hall effect transducer ( totally isolates the
mains supply) feeding a true rms converter IC and then a 3.5 digit LED
display. There are two ranges, 2A and 20A with 1mA and 10mA resolution
respectively.

A standard 3 pin outlet is fitted to the front and all jobs get plugged in
there.

A BNC socket on the back of the unit provides a waveform for the scope that
is either 1V or 100mV per amp of AC current. Signal bandwidth is DC to 100
kHz and max output is +/- 10V, so current surges up to 100 amps peak can be
seen on the scope.

The current meter's electronics has its own AC lead so the Variac does not
affect it.

The set up easily caters for the smallest plug pak (wall wart) right up to
2.5kW/ch stage lighting dimmers and the largest power amps. Been in
continuous use now since 1996.



..... Phil

Phil Allison wrote:
Guitar amps regularly arrive with either no fuse or a glaringly wrong
size or type fuse - ie fast fuses in the AC.

I see Australian musicians have discovered the "universal replacement"
fuse, too - it's the fuse in a particular physical size with the biggest
number preceding the "A" printed on the box. It is guaranteed not to
blow - something else will usually pop before the fuse does.

I used to work on trucks where AGC 10 A fuses were routinely replaced
with 30 A fuses in an attempt to stop the fuse from blowing. Usually
the actual problem was that an added wire had been run through a hole
with no grommet, sleeving, etc and was grounding out.

For a while in the 70s, some US cars had "SFE" fuses that were all 0.25"
diameter but different lengths - lower ratings were physically shorter -
to help prevent overfusing. An SFE 4 was a little over 0.5", and an
SFE 20 was the same length (1.25") as an AGC fuse. I think it was a
good idea, but it went away with the changeover to the flat blade fuses.

However, the ones I really hate arrive with NO fuse cap in the holder.

At a previous employer, one of our products was in a 6U 19" rackmount
chassis with two holders for 5 x 20 mm fuses on the back. We shipped
this in its own cardboard box, and it always showed up with everything
intact. Our customer then bolted that chassis into their cabinet, along
with other equipment, and shipped the whole shebang on a flatbed truck
to the site. When it got to site, there was a pretty good chance that
the fuse holder caps would be missing. We told them a) don't ship it
that way and b) put a piece of tape over the caps before shipping. They
ignored a), did b), and asked us for a case lot of replacement caps,
which we gave them.

In the previous generation of that product, the fuses were in the power
inlet module - one where you have to remove the main power connector to
open the little flap that lets you change the fuses. I don't know
whether that inlet module was eliminated from the design for cost or
customer reasons. (It wasn't quite an IEC inlet module, because the
incoming power was DC with a unique connector, but it was the same
idea.)

Matt Roberds

Phil Allison

Guitar amps regularly arrive with either no fuse or a glaringly wrong
size or type fuse - ie fast fuses in the AC.

I see Australian musicians have discovered the "universal replacement"
fuse, too - it's the fuse in a particular physical size with the biggest
number preceding the "A" printed on the box. It is guaranteed not to
blow - something else will usually pop before the fuse does.

I used to work on trucks where AGC 10 A fuses were routinely replaced
with 30 A fuses in an attempt to stop the fuse from blowing.


** I have a box full of 20A, 25A 30A and 35A automotive 3AG fuses pulled
from guitar and power amps.

Not to mention all the blown ones wrapped in foil paper from a cigarette
pack.

However, the ones I really hate arrive with NO fuse cap in the holder.

At a previous employer, one of our products was in a 6U 19" rackmount
chassis with two holders for 5 x 20 mm fuses on the back. We shipped
this in its own cardboard box, and it always showed up with everything
intact. Our customer then bolted that chassis into their cabinet, along
with other equipment, and shipped the whole shebang on a flatbed truck
to the site. When it got to site, there was a pretty good chance that
the fuse holder caps would be missing. We told them a) don't ship it
that way and b) put a piece of tape over the caps before shipping. They
ignored a), did b), and asked us for a case lot of replacement caps,
which we gave them.


** In my example, the fuse caps were removed by the owners and thrown away
!!!

They all wrongly imagine techs can easily get spare ones to suit.

With many USA built guitar amps, it means drilling or punching a new hole in
the chassis to fit a new holder.


In the previous generation of that product, the fuses were in the power
inlet module - one where you have to remove the main power connector to
open the little flap that lets you change the fuses.


** That level sophistication of stops most of them in their tracks.



..... Phil

Em quinta-feira, 17 de outubro de 2013 20h55min39s UTC-3, Dan escreveu:
I need to replace a PSU fuse in an LCD monitor. The open fuse is

ceramic, 5 x 20 mm, and marked "T3.15AH250V", with no obvious spacing

between the various markings. I understand the speed rating (T) and the

voltage (250V), but I'm unclear on the amperage. Is it 3.15 amps, .15

amps, or 15 amps? Did some searching, but all I can find are pages

trying to sell fuses, not any giving how to read the ratings.



TIA



Dan

Hi,

The Ceramic Fuse can be found in a specialized electronic store. But this fuse is a specific component. I have the same problem. The Fuse 3,15a/H250v. You need to replace the same component because there is a reason about the form and type in this device. Be carefull. I try another fuse and got a explosion. Yeah.

On Thursday, October 17, 2013 at 8:29:15 PM UTC-5, Phil Allison wrote:
"mike"

Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V, T3..15
H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm (3/16" X
3/4"), 3.15A 250V, SLOW-blow (Time Delay)


** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".



... Phil

Hey, I know there is some joking around going on here (and some animosity, too apparently) but the "T" DOES actually stand for: "T = Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @ ten times the rated current)"

Correct? Or am I missing something? BTW that comes from this google cached page:

http://webcache.googleusercontent.co...&ct=clnk&gl=us

I'm just trying to learn, I've got to replace that same damn fuse, and I'm frankly having a bitch of a time figuring out what's causing it to blow (it's the psu from a 32' flatscreen tv if that matters) Replaced a bunch of bad caps, and it powers up for about 3 seconds with a nice picture, and then bam blown fuse. Does rogaine help for hair regrowth that you pulled out yourself lol?

On Thursday, January 29, 2015 at 1:40:34 AM UTC-6, wrote:
On Thursday, October 17, 2013 at 8:29:15 PM UTC-5, Phil Allison wrote:
"mike"

Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V, T3.15
H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm (3/16" X
3/4"), 3.15A 250V, SLOW-blow (Time Delay)


** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".



... Phil

Hey, I know there is some joking around going on here (and some animosity, too apparently) but the "T" DOES actually stand for: "T = Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @ ten times the rated current)"

Correct? Or am I missing something? BTW that comes from this google cached page:

http://webcache.googleusercontent.co...&ct=clnk&gl=us

I'm just trying to learn, I've got to replace that same damn fuse, and I'm frankly having a bitch of a time figuring out what's causing it to blow (it's the psu from a 32' flatscreen tv if that matters) Replaced a bunch of bad caps, and it powers up for about 3 seconds with a nice picture, and then bam blown fuse. Does rogaine help for hair regrowth that you pulled out yourself lol?

Oh and another thing that has me curious is the fuse was wrapped in rubber shrinkwrap, even though it wasn't anywhere near anything metallic that could short it out, any ideas why?

On Wed, 28 Jan 2015 23:46:26 -0800, dave wrote:

Oh and another thing that has me curious is the fuse was wrapped in
rubber shrinkwrap, even though it wasn't anywhere near anything metallic
that could short it out, any ideas why?

That's easier to guess: to protect anyone who happens to be looking at the
fuse when it blows and the glass casing shatters?

Mike.

wrote:



** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".


Hey, I know there is some joking around going on here (and some animosity, too apparently) but the "T" DOES actually stand for: "T = Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @ ten times the rated current)"

Correct? Or am I missing something?


** Yes - the word with that T as the initial letter.

It's the German word "Trage" meaning "dragged out" or leaden.

All the letter codes on common fuses are for German words.

F = " Flink " for quickly or rapid.

http://www.thefusewarehouse.com/page...e_markings.php


Amaze your friends...


.... Phil

On 1/28/2015 11:40 PM, wrote:
On Thursday, October 17, 2013 at 8:29:15 PM UTC-5, Phil Allison wrote:
"mike"

Ok, let me quote the amazon page for you.

QUALITY USA brand fuses!! Set of 5 pieces, T3.15AH250V, T3.15A 250V, T3.15
H250V, T3.15A 250V, T3.15H250V cartridge CERAMIC fuses 5X20mm (3/16" X
3/4"), 3.15A 250V, SLOW-blow (Time Delay)


** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".



... Phil

Hey, I know there is some joking around going on here (and some animosity, too apparently) but the "T" DOES actually stand for: "T = Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @ ten times the rated current)"

Correct? Or am I missing something? BTW that comes from this google cached page:

http://webcache.googleusercontent.co...&ct=clnk&gl=us

I'm just trying to learn, I've got to replace that same damn fuse, and I'm frankly having a bitch of a time figuring out what's causing it to blow (it's the psu from a 32' flatscreen tv if that matters) Replaced a bunch of bad caps, and it powers up for about 3 seconds with a nice picture, and then bam blown fuse. Does rogaine help for hair regrowth that you pulled out yourself lol?

Here's the dark side of replacing caps.
Switching power supplies often work by stuffing pulses of current thru
inductors into caps from a higher voltage.
Primary failure mode of caps is increased series resistance, ESR.

When that resistance increases, there's a step in voltage across the cap
when the current is being stuffed in. The regulator is looking at
average voltage, so it reduces the output voltage slightly to make the
average voltage, including that step, to be the desired output.

Over time, that step gets bigger and bigger. You don't see any symptoms
until the step gets big enough to disrupt the circuit.

By the time the system shuts down, damage may have been done.

Had one monitor where the system processor had been fried by the peak
voltage. Had 19V spikes on a 5V supply.

In another, there were totem-pole fets driving the transformer for the
backlight. One of them had been damaged and had high leakage. The
backlight came up and ran for a few seconds until the other fet overheated
and blew the fuse.

That's why it's often a good idea to change all the caps at once.
If you're lucky, and most are, you caught it before permanent damage was
done.

So, back to your problem...
Most any fuse of the correct current rating should work for more than
three seconds. Yes, the right fuse is best, but fix the circuit first.

On Wed, 28 Jan 2015 23:40:28 -0800 (PST), wrote:

... (it's the psu from a 32' flatscreen tv if that matters)

Wow! Are you operating a small drive-in multi-media center? :-)

On 01/29/2015 1:16 AM, Phil Allison wrote:
wrote:



** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".


Hey, I know there is some joking around going on here (and some animosity, too apparently) but the "T" DOES actually stand for: "T = Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @ ten times the rated current)"

Correct? Or am I missing something?


** Yes - the word with that T as the initial letter.

It's the German word "Trage" meaning "dragged out" or leaden.

All the letter codes on common fuses are for German words.

F = " Flink " for quickly or rapid.

http://www.thefusewarehouse.com/page...e_markings.php


Amaze your friends...


.... Phil


Isn't that chart just for the European fuses? It is interesting none the
less...

John :-#)#

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

On Thursday, January 29, 2015 at 9:44:57 AM UTC-6, John Robertson wrote:
On 01/29/2015 1:16 AM, Phil Allison wrote:
wrote:



** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".


Hey, I know there is some joking around going on here (and some animosity, too apparently) but the "T" DOES actually stand for: "T = Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @ ten times the rated current)"

Correct? Or am I missing something?


** Yes - the word with that T as the initial letter.

It's the German word "Trage" meaning "dragged out" or leaden.

All the letter codes on common fuses are for German words.

F = " Flink " for quickly or rapid.

http://www.thefusewarehouse.com/page...e_markings.php


Amaze your friends...


.... Phil


Isn't that chart just for the European fuses? It is interesting none the
less...

John :-#)#

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

Thanks everyone for being so helpful, it's always cool to pick the brains of some guys who know what they're doing ps about the shrink wrap, it's not a glass fuse, it's a ceramic fuse so the wrapping is still sort of a mystery I guess. Anyway thanks again I'll keep plugging away at it til I figure it out

Dave

"Phil Allison" wrote in message
...
wrote:



** Got any idea what the letter "T" stands for ?

Hint - it ain't "time".


Hey, I know there is some joking around going on here (and some
animosity, too apparently) but the "T" DOES actually stand for: "T =
Time. Time Delay or Slow Blow.(Typically open between 100 and 300 ms @
ten times the rated current)"

Correct? Or am I missing something?


** Yes - the word with that T as the initial letter.

It's the German word "Trage" meaning "dragged out" or leaden.

All the letter codes on common fuses are for German words.

F = " Flink " for quickly or rapid.

http://www.thefusewarehouse.com/page...e_markings.php



Nah. They've got that wrong Phil. "FF" is ****in' Fast "F" is just Fast
"M" is Meedjum" "T" is Time and "TT" is Tea Time which I believe means
you've got enough time to make a cup of tea while it decides whether to blow
.... :-)

Arfa
Amaze your friends...


... Phil

Arfa Daily wrote:


Nah. They've got that wrong Phil.
"FF" is ****in' Fast "F" is just Fast
"M" is Meedjum" "T" is Time and "TT" is Tea Time which I believe means
you've got enough time to make a cup of tea while it decides whether to blow
... :-)


** Works for me....



..... Phil

John Robertson wrote:



** Yes - the word with that T as the initial letter.

It's the German word "Trage" meaning "dragged out" or leaden.

All the letter codes on common fuses are for German words.

F = " Flink " for quickly or rapid.

http://www.thefusewarehouse.com/page...e_markings.php



Isn't that chart just for the European fuses?


** Whooah - hold on a mo there.

Q. Who uses European standard fuses ?

A. Everyone does.

Common appliance fuses come in just two sizes: 20x5mm and 6.3x30mm or 3AG.

European and Asian makers produce both sizes and dominate the market because of lower cost. In 40 years of buying and using such fuses, I cannot remember seeing a pack labelled "Made in USA"



..... Phil

On 01/30/2015 5:41 AM, Phil Allison wrote:
John Robertson wrote:



** Yes - the word with that T as the initial letter.

It's the German word "Trage" meaning "dragged out" or leaden.

All the letter codes on common fuses are for German words.

F = " Flink " for quickly or rapid.

http://www.thefusewarehouse.com/page...e_markings.php



Isn't that chart just for the European fuses?


** Whooah - hold on a mo there.

Q. Who uses European standard fuses ?

A. Everyone does.

Common appliance fuses come in just two sizes: 20x5mm and 6.3x30mm or 3AG.

European and Asian makers produce both sizes and dominate the market because of lower cost. In 40 years of buying and using such fuses, I cannot remember seeing a pack labelled "Made in USA"



..... Phil




On this side of the pond we have Cooper/BUSS fuses which say "Made in
the USA" in my stock, just got some from Digi-Key.

I think you are in the UK, right Phil?

John :-#)#

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

John Robertson wrote:


Isn't that chart just for the European fuses?


** Whooah - hold on a mo there.

Q. Who uses European standard fuses ?

A. Everyone does.

Common appliance fuses come in just two sizes: 20x5mm and 6.3x30mm or 3AG.

European and Asian makers produce both sizes and dominate the market because of lower cost. In 40 years of buying and using such fuses, I cannot remember seeing a pack labelled "Made in USA"



On this side of the pond we have Cooper/BUSS fuses which say "Made in
the USA" in my stock, just got some from Digi-Key.

I think you are in the UK, right Phil?


** No, Sydney Australia.

Fuses come from either Asia or Europe via Farnell.



.... Phil