Author Topic: EEVblog #1160 - Weller Responds  (Read 158263 times)

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Offline Mr. Scram

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Re: EEVblog #1160 - Weller Responds
« Reply #775 on: January 05, 2019, 03:45:37 pm »
Dave, would you be availabe for a test where a Weller unit is *not* removed from mains after it started smoking ?
Some Weller fanboys here say that there is no safety issue because no open flames occurred.
Blame your lack of evidence, instead of calling people names. Please note my quote below.

People seem to think I'm arguing one way or the other. I'm not. I'm seeing claims being made about the station being dangerous without a fuse. I've asked whether this danger can be quantified, as that's how you know how big the problem actually is. It seems this hasn't happened yet, so it's premature to adamantly claim there's a significant danger. Crucifying a company with so little to go on is silly. That's all I've been saying.

With a few stations you could do at least some testing. A 110V station run at 230V until completely failed would be interesting, to see whether it fails safe. Another would be to add a primary fuse and to see whether that protects the unit completely from 230V. Either would represent user error and isn't representative of what it should reasonsably withstand as it's grossly overloading the device, but it would at least end some of the discussion here. If anyone has other ideas for tests to assess the safety at regular voltages, please post them here. For now I'm putting down $50 to facilitate or aid the purchase of a few units. Let me know what everyone is willing to contribute.
 

Offline Mr. Scram

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Re: EEVblog #1160 - Weller Responds
« Reply #776 on: January 05, 2019, 03:47:24 pm »
Nope, I'm done.
But anyone who wants to do this, I'd say that there are large variables in this, so testing just one and getting a negative result doesn't tell you much, you need to test a number of them.
What potential variables do you see?
 

Offline Wolfgang

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Re: EEVblog #1160 - Weller Responds
« Reply #777 on: January 05, 2019, 03:51:22 pm »
Dave, would you be availabe for a test where a Weller unit is *not* removed from mains after it started smoking ?
Some Weller fanboys here say that there is no safety issue because no open flames occurred.
Blame your lack of evidence, instead of calling people names. Please note my quote below.

People seem to think I'm arguing one way or the other. I'm not. I'm seeing claims being made about the station being dangerous without a fuse. I've asked whether this danger can be quantified, as that's how you know how big the problem actually is. It seems this hasn't happened yet, so it's premature to adamantly claim there's a significant danger. Crucifying a company with so little to go on is silly. That's all I've been saying.

With a few stations you could do at least some testing. A 110V station run at 230V until completely failed would be interesting, to see whether it fails safe. Another would be to add a primary fuse and to see whether that protects the unit completely from 230V. Either would represent user error and isn't representative of what it should reasonsably withstand as it's grossly overloading the device, but it would at least end some of the discussion here. If anyone has other ideas for tests to assess the safety at regular voltages, please post them here. For now I'm putting down $50 to facilitate or aid the purchase of a few units. Let me know what everyone is willing to contribute.

I think the standpoints have been sufficiently exchanged, I am looking for a potential test site, and I have made suggestions for the content and procedures of such a test. So ...  :horse:
 

Offline Mr. Scram

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Re: EEVblog #1160 - Weller Responds
« Reply #778 on: January 05, 2019, 03:55:43 pm »
I think the standpoints have been sufficiently exchanged, I am looking for a potential test site, and I have made suggestions for the content and procedures of such a test. So ...  :horse:
If you could also refrain calling people who disagree with you names, we're all good.
 

Offline Mr. Scram

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Re: EEVblog #1160 - Weller Responds
« Reply #779 on: January 05, 2019, 03:56:57 pm »
LMGTFY.

Looks like this thread's over. All that's left is trolls and people who refuse to see common sense.
I've been trying to set up a practical experiment, as it's clear it will be an endless discussion otherwise. Unfortunately, very few donations have materialized. It's a bit disappointing that some people making adamant claims aren't as keen on having them tested. I've put in $50 and I think Wolfgang has done the same, right? Will you make another $50 donation?
 

Offline fsr

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Re: EEVblog #1160 - Weller Responds
« Reply #780 on: January 05, 2019, 03:57:50 pm »
That didn't proved anything to me.
If the smoking, fuseless transformer looks like it's safe to you, well, you're free to think whatever you like. But don't expect that most people will think the same.

And as i said, you cannot guarantee the safety of a transformer that was smoking it's enamel. A fuse would have blown before that happens.
So, why not to include a fuse, when it's very cheap, everyone else uses it, and would improve the safety of the device? Nobody designs mains connected equipment without a mains fuse, because when shit goes wrong with mains, it goes really wrong. Too much power there. Would you remove the fuse just because your found some certification that won't require one? I wouldn't expect a simple 40 watts soldering iron to be fused, because, well, there's no much space to even put a fuse in there, and it has just a heating element inside, and that's it. Neither would i leave it connected and go away for any significant amount of time. But a soldering station? Is there even another fuseless soldering station out there?

Maybe to weller this falls under the ridiculous reasoning of "this may cost $1 per unit, but in 1,000,000 units, that's $1,000,000 we could save". But then, why not just charge $1 more, and be done with it?

Maybe it's a design issue or manufacturing error? But then, it's crazy if they don't fix it, as they could get sued. At least go the "xbox way", and provide an external safety.

And even more important: if they have a good reason for the fuse to not be there, just share that information with the electronics community!!
Luckily we can test whether a fuse would have blown before that happens. We just need some funds to do so. What are you willing to contribute to the testing funds? Maybe $50?
Nope. Not my problem.
Weller chose to send dave's question to marketing to give him that empty answer, instead of an engineer that could answer why it doesn't need a fuse. They can still do that any time they want. So, i think that the most reasonable thing to expect in this case, is that they don't have a better answer for us.
You connect a correctly fused 110v transformer to 220v, and the fuse will blow, anyways. That's what fuses do. If a transformer smokes a lot before a fuse blows, that's not very good engineering.
 
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Online coppercone2

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Re: EEVblog #1160 - Weller Responds
« Reply #781 on: January 05, 2019, 04:02:27 pm »
how is it not dangerous if its making a bunch of toxic smoke. if you say its not dangerous i wanna see you put your nose in the vent.

there are two problems with this device.

electronics labs have hepa filters, carbon solder fume filters, air vents, temperature control, etc.. but its suddenly ok to run a choo choo in them/....

it's like typically a violation in a factory to solder without some kind of fan to protect you from high concentrations at least, or better yet a carbon filter, ok maybe getting a carbon filter is a bit of a fairy tale, but still. usually at least a fan is expected to suck some fumes away from your nose. and thats natural rosin solder flux fumes. we are talking about some kind of highly engineered chemical compound which decomposes into god knows what.
« Last Edit: January 05, 2019, 04:11:43 pm by coppercone2 »
 

Offline Mr. Scram

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Re: EEVblog #1160 - Weller Responds
« Reply #782 on: January 05, 2019, 04:23:08 pm »
Nope. Not my problem.
Weller chose to send dave's question to marketing to give him that empty answer, instead of an engineer that could answer why it doesn't need a fuse. They can still do that any time they want. So, i think that the most reasonable thing to expect in this case, is that they don't have a better answer for us.
You connect a correctly fused 110v transformer to 220v, and the fuse will blow, anyways. That's what fuses do. If a transformer smokes a lot before a fuse blows, that's not very good engineering.
Enough of a problem for well over 30 replies in this thread, but not for doing some simple testing? That's not really putting your money where your mouth is.
 

Offline drussell

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Re: EEVblog #1160 - Weller Responds
« Reply #783 on: January 05, 2019, 04:43:14 pm »
how is it not dangerous if its making a bunch of toxic smoke
....
electronics labs have hepa filters, carbon solder fume filters, air vents, temperature control, etc.. but its suddenly ok to run a choo choo in them/....
...
it's like typically a violation in a factory to solder without some kind of fan to protect you from high concentrations at least, or better yet a carbon filter, ok maybe getting a carbon filter is a bit of a fairy tale, but still. usually at least a fan is expected to suck some fumes away from your nose. and thats natural rosin solder flux fumes. we are talking about some kind of highly engineered chemical compound which decomposes into god knows what.

There is a difference between sitting in smoke and fumes all day long and a one-time event that emits some smoke during a complete failure.

As for the solder fumes, I think the concern is more about potential lead compounds in the fumes rather than with the rosin flux fumes themselves, though it could certainly be an irritant with prolonged exposure, etc.
 

Online coppercone2

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Re: EEVblog #1160 - Weller Responds
« Reply #784 on: January 05, 2019, 04:56:26 pm »
thats a good point, with how hot this thing gets it might actually be capable of making metal fumes, unlike soldering.
 

Offline drussell

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Re: EEVblog #1160 - Weller Responds
« Reply #785 on: January 05, 2019, 04:57:57 pm »
I've been trying to set up a practical experiment, as it's clear it will be an endless discussion otherwise. Unfortunately, very few donations have materialized. It's a bit disappointing that some people making adamant claims aren't as keen on having them tested.

I am most curious as to what point (as the input voltage is raised,) transformers like this typically start to saturate and dissipate significant heat in the primary winding itself.  There will be a point at which the primary is dissipating virtually all the current that the whole device is supposed to be able to draw, hence will not blow a primary fuse because it is still within the ratings, but will be coming out as primary heating, where the primary should normally dissipate very little energy in regular operation.

The primary saturated and ran well beyond 4 times normal power dissipation, and then likely went into accelerated melt down as the enamel was burnt off and the primary turns shorted.

The primary normally dissipates very little current.  Most of the energy is passed to the secondary and whatever is connected, not dissipated in the primary.  The "4 times normal" is effectively nonsense when it comes to primary power dissipation.

Most transformers will have some point where the input voltage, frequency and waveshape makes the primary dissipate far too much power for the transformer to survive but is still well within the total input current range that the devices would be fused for.

People are essentially arguing, therefore, that not only should a primary fuse be mandatory but also a mandatory thermal fuse inside the transformer.  Those ones that once they decide to open (often not due to a fault) your transformer is usually junk because the thermal fuse is buried deep within the windings making repair impractical.
 

Offline Wolfgang

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Re: EEVblog #1160 - Weller Responds
« Reply #786 on: January 05, 2019, 05:15:18 pm »
Agreed. For the reasons explained the good products have a (resettable) thermal fuse (works against moderate overvoltages and other problems inside), plus a normal fuse against hard fails.
You could try this out with a variac (at least I do this if I need to torture my circuits to make sure they have large safety margins and fail safe).
 
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Offline drussell

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Re: EEVblog #1160 - Weller Responds
« Reply #787 on: January 05, 2019, 05:24:14 pm »
Neither do I, especially this "if you don't agree that a fuse must be mandatory in every case, you must be a corporate apologist or paid shill." nonsense.

I haven't seen anyone say that here.

From the last couple pages:

I am asking myself if all the ardent Weller defenders here are either dealers, stockholders or otherwise affiliated with Weller
...

'They' may be pumping the two corptrolls with 'fiery' emails to get this fuseless fiasco wrapped up and gone by YESTERDAY,

...etc.

Apparently to some, anyone who is looking for some quantifiable measurements to provide data on this type of failure mode (which I think would be extremely interesting and enlightening from an engineering perspective) must be a "Weller Fanboy" of one sort or another, even those of us who don't own a single one. 

(I do own an old Ungar, from pre-Weller-acquisition times.  It is still going strong.  :) )
« Last Edit: January 05, 2019, 09:17:43 pm by drussell »
 
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Offline fsr

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Re: EEVblog #1160 - Weller Responds
« Reply #788 on: January 05, 2019, 05:31:38 pm »
Nope. Not my problem.
Weller chose to send dave's question to marketing to give him that empty answer, instead of an engineer that could answer why it doesn't need a fuse. They can still do that any time they want. So, i think that the most reasonable thing to expect in this case, is that they don't have a better answer for us.
You connect a correctly fused 110v transformer to 220v, and the fuse will blow, anyways. That's what fuses do. If a transformer smokes a lot before a fuse blows, that's not very good engineering.
Enough of a problem for well over 30 replies in this thread, but not for doing some simple testing? That's not really putting your money where your mouth is.
Web forums entertain me, but i won't waste any money on that. You can pay for that if you want, or weller can do it, and/or answer something better for the electronics community.
Nobody will just give away money to random people in a web forum, anyways, you know?
 

Offline drussell

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Re: EEVblog #1160 - Weller Responds
« Reply #789 on: January 05, 2019, 05:34:58 pm »
Agreed. For the reasons explained the good products have a (resettable) thermal fuse (works against moderate overvoltages and other problems inside), plus a normal fuse against hard fails.

Assuming you would be "allowed" to use a resettable thermal switch under this new regulatory regime.  :)

You're not normally supposed to design things to operate in such a way that it could potentially cycle off a thermal limit switch of some sort, though.  If there is a thermostat / thermal switch, you still normally need a manual-reset cutout or one-time fuse.  This could mean you have a thermal switch at a lower temperature and then a fuse at a higher temperature in some cases, I suppose, if we're trying to cover all bases, etc. or I suppose just a manually resettable cutout, perhaps...

Quote
You could try this out with a variac (at least I do this if I need to torture my circuits to make sure they have large safety margins and fail safe).

I can even do one better than a Variac.  I have the apparatus to generate AC at up to 2400W with arbitrary frequency and waveshape.  :)
 

Offline Wolfgang

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Re: EEVblog #1160 - Weller Responds
« Reply #790 on: January 05, 2019, 05:40:58 pm »
Agreed. For the reasons explained the good products have a (resettable) thermal fuse (works against moderate overvoltages and other problems inside), plus a normal fuse against hard fails.

Assuming you would be "allowed" to use a resettable thermal switch under this new regulatory regime.  :)

You're not normally supposed to design things to operate in such a way that it could potentially cycle off a thermal limit switch of some sort, though.  If there is a thermostat / thermal switch, you still normally need a manual-reset cutout or one-time fuse.  This could mean you have a thermal switch at a lower temperature and then a fuse at a higher temperature in some cases, I suppose, if we're trying to cover all bases, etc. or I suppose just a manually resettable cutout, perhaps...

Quote
You could try this out with a variac (at least I do this if I need to torture my circuits to make sure they have large safety margins and fail safe).

I can even do one better than a Variac.  I have the apparatus to generate AC at up to 2400W with arbitrary frequency and waveshape.  :)

You live in luxury.  ^-^ TEA addict ?
 

Offline Mr. Scram

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Re: EEVblog #1160 - Weller Responds
« Reply #791 on: January 05, 2019, 05:50:49 pm »
Web forums entertain me, but i won't waste any money on that. You can pay for that if you want, or weller can do it, and/or answer something better for the electronics community.
Nobody will just give away money to random people in a web forum, anyways, you know?
You're eager to harm the reputation of a company based on conjecture, but are not willing to spend a dime to back it up. At least we know what you feel your statements are worth. I've already said I'd put in $50 of my own, but feel it should be community effort of all those making claims here. And I'm not even making claims, I'm just curious what claims hold up.
 

Offline Mr. Scram

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Re: EEVblog #1160 - Weller Responds
« Reply #792 on: January 05, 2019, 05:53:13 pm »
Assuming you would be "allowed" to use a resettable thermal switch under this new regulatory regime.  :)

You're not normally supposed to design things to operate in such a way that it could potentially cycle off a thermal limit switch of some sort, though.  If there is a thermostat / thermal switch, you still normally need a manual-reset cutout or one-time fuse.  This could mean you have a thermal switch at a lower temperature and then a fuse at a higher temperature in some cases, I suppose, if we're trying to cover all bases, etc. or I suppose just a manually resettable cutout, perhaps...

I can even do one better than a Variac.  I have the apparatus to generate AC at up to 2400W with arbitrary frequency and waveshape.  :)
Interesting. That should allow for some very interesting experiments. What have you used that for?
 

Offline drussell

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Re: EEVblog #1160 - Weller Responds
« Reply #793 on: January 05, 2019, 05:57:26 pm »
Quote
I can even do one better than a Variac.  I have the apparatus to generate AC at up to 2400W with arbitrary frequency and waveshape.  :)

You live in luxury.  ^-^ TEA addict ?

LOL...  I've tried to not fall down that particular addiction rabbit hole. 

Not really sure if it is actually working out very well, though... or so it would seem.   ;)
 

Online Kleinstein

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Re: EEVblog #1160 - Weller Responds
« Reply #794 on: January 05, 2019, 08:58:31 pm »
How a transformer behaved with higher than normal voltage depends on the construction and size. Toroid transformers often use there core to a relatively high magnetization, as the grain oriented core allows this. Here even moderate high voltage, like 20% can cause huge current spikes.

EI cores are less sensitive as the onset of saturation is more gradual. Some transformers made for short time use might go quite high too.
The size also makes a difference, as the relative importance of wire resistance is higher at small size. Especially transformers  < 1 VA can behave wired - up to the point of taking less power with a short on the secondary than in the no load case. Here the wire resistance could make the short circuit proof.

In not too small transformers the power loss in the primary and secondary winding is about the same, slightly more in the primary with small transformers. When going into saturation there can be quite some extra loss, mainly proportional to the square of the current, as it's due to the resistance. So there is extra loss in the primary only if there is more current. Having no current on the secondary would only help keeping the primary side cooler due to the thermal coupling. So it's only the question whether a fuse can be accurate enough to blow before the transformer gets too hot.

A thermal fuse is better here as it can also catch cases of poor ventilation or a shorted winding and it is about the right speed. Even a slow blow fuse is usually fast than the thermal time constant of a transformer.
 

Offline timelessbeing

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Re: EEVblog #1160 - Weller Responds
« Reply #795 on: January 05, 2019, 09:01:51 pm »
you cannot guarantee the safety of a transformer that was smoking it's enamel.
Why not?

Because the enamel melts and the turns short out, and this likely happens in a progressive accelerated fashion, effectively feeding on itself in a thermal runaway of sorts.
... until it goes open circuit. Right?

Nope, mine didn't.
If you had left it plugged in. Obviously. You were arguing that the transformer is unsafe.
Your responses to this topic are meaningless because you aren't even following.
« Last Edit: January 05, 2019, 09:07:06 pm by timelessbeing »
 

Offline timelessbeing

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Offline floobydust

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Re: EEVblog #1160 - Weller Responds
« Reply #797 on: January 05, 2019, 10:27:54 pm »
you cannot guarantee the safety of a transformer that was smoking it's enamel.
Why not?

Because the enamel melts and the turns short out, and this likely happens in a progressive accelerated fashion, effectively feeding on itself in a thermal runaway of sorts.
... until it goes open circuit. Right?

Nope, mine didn't.
If you had left it plugged in. Obviously. You were arguing that the transformer is unsafe.
Your responses to this topic are meaningless because you aren't even following.

UL considers the breaker tripping during transformer tests a FAIL:

UL 1585; 22.5
"... a risk of fire or electric shock is considered to exist when any of the following occurs:
a)  Opening of branch circuit protection;
b)  Opening of grounding fuse;
c)  Glowing or flaming of cheesecloth;
d)  Emission of molten material from the transformer enclosure;
e)  Development of any opening in the enclosure that exposes live parts at a potential of more than 42.4 volts peak to any other part or to ground; or
f)  Dielectric breakdown as a result of the Dielectric Voltage-Withstand After Overload Heating Test, Section 33.

Troll be gone
 
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Offline Mr. Scram

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Re: EEVblog #1160 - Weller Responds
« Reply #798 on: January 05, 2019, 10:29:57 pm »
UL considers the breaker tripping during transformer tests a FAIL:

UL 1585; 22.5
"... a risk of fire or electric shock is considered to exist when any of the following occurs:
a)  Opening of branch circuit protection;
b)  Opening of grounding fuse;
c)  Glowing or flaming of cheesecloth;
d)  Emission of molten material from the transformer enclosure;
e)  Development of any opening in the enclosure that exposes live parts at a potential of more than 42.4 volts peak to any other part or to ground; or
f)  Dielectric breakdown as a result of the Dielectric Voltage-Withstand After Overload Heating Test, Section 33.

Troll be gone
Another "People don't agree with me. They must be trolls!" How quaint.

The breaker didn't trip here, as far as I know.
 

Offline floobydust

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Re: EEVblog #1160 - Weller Responds
« Reply #799 on: January 05, 2019, 10:32:11 pm »
It did trip, as I recall Dave mentioning. The breaker is to protect the building wiring, not devices.
 


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