Author Topic: EEVblog #1160 - Weller Responds  (Read 48641 times)

0 Members and 1 Guest are viewing this topic.

Offline drussell

  • Super Contributor
  • ***
  • Posts: 1049
  • Country: ca
  • Hardcore Geek
Re: EEVblog #1160 - Weller Responds
« Reply #800 on: January 06, 2019, 04:34:58 am »
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

  • Super Contributor
  • ***
  • Posts: 1122
  • Country: de
  • Its great if it finally works !
    • Electronic Projects for Fun
Re: EEVblog #1160 - Weller Responds
« Reply #801 on: January 06, 2019, 04:40:58 am »
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

  • Super Contributor
  • ***
  • Posts: 7296
  • Country: 00
  • Display aficionado
Re: EEVblog #1160 - Weller Responds
« Reply #802 on: January 06, 2019, 04:50:49 am »
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

  • Super Contributor
  • ***
  • Posts: 7296
  • Country: 00
  • Display aficionado
Re: EEVblog #1160 - Weller Responds
« Reply #803 on: January 06, 2019, 04:53:13 am »
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

  • Super Contributor
  • ***
  • Posts: 1049
  • Country: ca
  • Hardcore Geek
Re: EEVblog #1160 - Weller Responds
« Reply #804 on: January 06, 2019, 04:57:26 am »
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

  • Super Contributor
  • ***
  • Posts: 5962
  • Country: de
Re: EEVblog #1160 - Weller Responds
« Reply #805 on: January 06, 2019, 07:58:31 am »
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

  • Frequent Contributor
  • **
  • Posts: 780
  • Country: 00
Re: EEVblog #1160 - Weller Responds
« Reply #806 on: January 06, 2019, 08:01:51 am »
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 06, 2019, 08:07:06 am by timelessbeing »
 

Offline timelessbeing

  • Frequent Contributor
  • **
  • Posts: 780
  • Country: 00
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 2698
  • Country: ca
Re: EEVblog #1160 - Weller Responds
« Reply #808 on: January 06, 2019, 09:27:54 am »
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
 
The following users thanked this post: thm_w, Electro Detective

Offline Mr. Scram

  • Super Contributor
  • ***
  • Posts: 7296
  • Country: 00
  • Display aficionado
Re: EEVblog #1160 - Weller Responds
« Reply #809 on: January 06, 2019, 09:29:57 am »
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

  • Super Contributor
  • ***
  • Posts: 2698
  • Country: ca
Re: EEVblog #1160 - Weller Responds
« Reply #810 on: January 06, 2019, 09:32:11 am »
It did trip, as I recall Dave mentioning. The breaker is to protect the building wiring, not devices.
 

Offline Mr. Scram

  • Super Contributor
  • ***
  • Posts: 7296
  • Country: 00
  • Display aficionado
Re: EEVblog #1160 - Weller Responds
« Reply #811 on: January 06, 2019, 09:35:18 am »
It did trip, as I recall Dave mentioning. The breaker is to protect the building wiring, not devices.
As far as I know, Dave pulled the plug. I may be mistaken.
 
The following users thanked this post: timelessbeing

Offline Wolfgang

  • Super Contributor
  • ***
  • Posts: 1122
  • Country: de
  • Its great if it finally works !
    • Electronic Projects for Fun
Re: EEVblog #1160 - Weller Responds
« Reply #812 on: January 06, 2019, 09:38:20 am »
I thinks thats correct. He pulled the plug to prevent the smoke detector going off, IIRC.
 

Offline drussell

  • Super Contributor
  • ***
  • Posts: 1049
  • Country: ca
  • Hardcore Geek
Re: EEVblog #1160 - Weller Responds
« Reply #813 on: January 06, 2019, 09:52:19 am »
It did trip, as I recall Dave mentioning. The breaker is to protect the building wiring, not devices.

Citation, please?

I don't believe Dave's particular mishap escapade blew a mains breaker.

I asked about this before, for example, in this post linked below, and never got any response:

why did it blow the breaker if its supposed to fuse??

Wait...  What?  Who blew what breaker now?   :-//
 

Offline timelessbeing

  • Frequent Contributor
  • **
  • Posts: 780
  • Country: 00
Re: EEVblog #1160 - Weller Responds
« Reply #814 on: January 06, 2019, 10:17:24 am »
UL considers the breaker tripping during transformer tests a FAIL ... Troll be gone
The following users thanked this post: Electro Detective

It was literally seconds. If I hadn't pulled the plug and tossed the unit in a box to trap the smoke, the building ...

It was mentioned in the video, and the topic. When people believe something hard enough, it starts to become reality in their head. But oh no ... I'm a troll and a corporate schill  ;D  People are starting to feel very threatened and take this VERY personally
« Last Edit: January 06, 2019, 10:21:34 am by timelessbeing »
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29192
  • Country: au
    • EEVblog
Re: EEVblog #1160 - Weller Responds
« Reply #815 on: January 06, 2019, 11:00:05 am »
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.

The one making the claim here is Weller.
They have asserted by their own actions and lack of technical response to this issue that a fuse is not worthwhile in a couple of their low end products, but is presumably worthwhile in all their other products.
Weller need to answer this, not the community.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29192
  • Country: au
    • EEVblog
Re: EEVblog #1160 - Weller Responds
« Reply #816 on: January 06, 2019, 11:03:08 am »
It did trip, as I recall Dave mentioning. The breaker is to protect the building wiring, not devices.
As far as I know, Dave pulled the plug. I may be mistaken.

Yes, I pulled the plug seconds after I noticed the smoke and dumped the whole thing in a box to prevent the smoke getting to the alarm sensors.
Yes the mains break did trip, but I do not know if it was the 16A overcurrent or the earth leakage built into the same breaker. The iron was working (LCD flashing) right up until I pulled the plug.
 
The following users thanked this post: Mr. Scram

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2041
  • Country: au
Re: EEVblog #1160 - Weller Responds
« Reply #817 on: January 06, 2019, 11:08:48 am »
@ DJ  99% sure from your report that pulling the plug caused the RCD part to trip, not the breaker 

RCBOs are great space savers and good enough for most situations

but not much help identifying trip issues of misbehaving gear.

« Last Edit: January 06, 2019, 11:13:26 am by Electro Detective »
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 2698
  • Country: ca
Re: EEVblog #1160 - Weller Responds
« Reply #818 on: January 06, 2019, 11:09:21 am »
It's was hilarious to rewatch the vids. EEVblog #1152 - 240V-120V = Magic Smoke! 4:10 "reflex reaction pulled the mains cord at the back of the thing"

Louis Rossmann: Weller sells irons WITHOUT FUSE ON 120V: DOESN'T CARE!

"even a burger flipper that's 16 years old stoned at McDonalds is gonna understand why it is that you need a mains fuse..."

Nope. Not here.

I also noticed the WE1010 PCB has a 4A fuse, so that's three protective devices on the secondary side.
Perhaps trolls can comment on why two fuses is better than none.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29192
  • Country: au
    • EEVblog
Re: EEVblog #1160 - Weller Responds
« Reply #819 on: January 06, 2019, 11:09:27 am »
You were arguing that the transformer is unsafe.

No, I was not.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29192
  • Country: au
    • EEVblog
Re: EEVblog #1160 - Weller Responds
« Reply #820 on: January 06, 2019, 11:15:48 am »
I also noticed the WE1010 PCB has a 4A fuse, so that's three protective devices on the secondary side.
Perhaps trolls can comment on why two fuses is better than none.

Yep, few want to discuss the actual issue, which is why Weller chose to have three series (not exactly cheap) protection devices on the secondary, yet zero protection on the primary, all the while providing primary protection on almost all of their other products like all their competitors and cheap clones do. It's laughable of course, and is the reason why this is massively embarrassing for Weller.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29192
  • Country: au
    • EEVblog
Re: EEVblog #1160 - Weller Responds
« Reply #821 on: January 06, 2019, 11:17:47 am »
@ DJ  99% sure from your report that pulling the plug caused the RCD part to trip, not the breaker 
RCBOs are great space savers and good enough for most situations
but not much help identifying trip issues of misbehaving gear.

Yes, I think it was the RCD too. But of course impossible to know 100% when they are an integrated device.
 

Offline HackedFridgeMagnet

  • Super Contributor
  • ***
  • Posts: 1931
  • Country: au
Re: EEVblog #1160 - Weller Responds
« Reply #822 on: January 06, 2019, 11:18:45 am »
It did trip, as I recall Dave mentioning. The breaker is to protect the building wiring, not devices.

Citation, please?


Quote
2.5   PROTECTION AGAINST OVERCURRENT 2.5.1   General Active conductors shall be protected by one or more devices that automatically disconnect the supply in the event of overcurrent, before such overcurrent attains a magnitude or duration that could cause injury to persons or livestock or damage because of excessive temperatures or electromechanical stresses in the electrical installation.

from AS/NZS3000:2007 (A new standard is now in effect ie. 1/1/2019,  but I doubt there has been any change to this concept.)

IMO not fusing the primary for a soldering iron is just shit engineering.

Ps. I just replaced fuses (slow blow)  in two HP/Agilent power supplies. 35A 60V. I am fairly sure these supplies suffered from an over voltage as they were plugged in while electricians were working/testing. They had no load but stopped working. Thankfully a reputable company saw fit to use primary fuses.
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2041
  • Country: au
Re: EEVblog #1160 - Weller Responds
« Reply #823 on: January 06, 2019, 11:21:58 am »
UL considers the breaker tripping during transformer tests a FAIL ... Troll be gone
The following users thanked this post: Electro Detective

It was literally seconds. If I hadn't pulled the plug and tossed the unit in a box to trap the smoke, the building ...

It was mentioned in the video, and the topic. When people believe something hard enough, it starts to become reality in their head. But oh no ... I'm a troll and a corporate schill  ;D 

People are starting to feel very threatened and take this VERY personally



@ timelessbeing, there's no feeling threatened or personal vibe here mate  :-//

(puts on Kevlar rig and face shield, downloading anti-malware update...)  :phew:


Back to the topic...   ;D

Regarding breakers:

DJ states he has a 16 amp RCBO breaker (single or dual space combined RCD/GFCI and MCB)


e.g. If a 140 amp transformer welder pulling constant and intermittent 15 to 35 amps current at 240v
at near and full short circuit conditions on the transformer secondary (during actual non stop arc welding with 3.2 or 4mm electrodes)
it will do it tough to pop the 16 amp breaker but may/will eventually...

this is assuming the welder and leads are in good shape with direct plug in connection to a standard GPO wall socket
(i.e. no amateurish backyarder flimsy 10 amp extension cord malarky) 


So what chance has a sizzling lil Weller trannie got to pop DJs breaker ?  > PowerBall win chances ?


At best if it's plugged in to a 4 or 6 way power strip board with a thermal breaker/Reset thingie, the ones with the small black or red switch usually near the cord entry,
it may heat up around the 8 to 12 amp range (depending on the breaker design/curve) and trip the power board.

i.e. you can forget about MCBs and RCDs popping...unless the Weller is pulling over 32 to 44 amps for over one minute
and or the IEC cord catches fire
and or IEC socket melts, falls inside/outside and shorts/welds itself. Then perhaps the MCB and or RCD 'may' trip

...assuming those devices have been tested and their switches exercised at least a few times yearly  ???


I'm sorta convinced if the Weller was allowed to keep going, and the adjacent insulation stripped windings merged/spot welded themselves together, instead of breaking,
then DJ would have had himself a nice block of red hot glowing metal, an unhappy ESD mat, barbequed bench, 

and lots and lots of Majique Smoke... 


btw: do I still need to donate the $50 now, after cobbling up this long winded electrical blab  ?  :'(
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29192
  • Country: au
    • EEVblog
Re: EEVblog #1160 - Weller Responds
« Reply #824 on: January 06, 2019, 11:23:20 am »
Remember the days when the fuse was on the front panel:

 
The following users thanked this post: floobydust, Electro Detective


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf