EEVblog #1160 - Weller Responds

[Fungus]

Is it possible to make a transformer safe without a primary fuse?

Yes, but probably expensive as you have to double the thickness of the wires and use a larger core that won't saturate.

Is this Weller safe?

Not at the wrong voltage.

It gave some smoke out, but was there a real possibility of a fire or an electrical hazard?

In a few seconds it got hot enough to melt enamel and the mains circuit breaker didn't trip, so... not looking good.

Plus: Smoke is a hazard all by itself and you shouldn't have to pay for a cleanup after something like this. Not for the lack of a 10 cent fuse.

[coppercone2]

You consider using the mains breaker as a primary safety feature of your product??? 

fired bro. I would literally fire you if that was the design you approved.

Could be plugged in through a extension cord etc... that shits supposed to be a back up. Your nuts.

Are you gonna use 20A rated cable to plug in a soldering iron too since your relying on the mains? come on.

this is a total no brainer I can't believe people are contemplating if this is a good idea!!!!

[Fungus]

You consider using the mains breaker as a primary safety feature of your product??? 

If you're referring to me, then:

No, I'm just reminding somebody of what actually happened in a real event (ie. not an imaginary one).

The thing stopped melting down because Dave pulled the plug. Who knows what would have happened if Dave had panicked and ran away.

[alxpo]

UL 1585 Class 2 transformers can be inherently protected by impedance or not inherently protected. The transformer certified as inherently protected do not catch fire in any circumstances and do not require a primary side fuse.

[coppercone2]

yea and whats gonna break the circuit? A circuit breaker. Or a mains fuse. How is that acceptable?

How do you ensure the transformer will not go full short circuit? The EEVBLOG circuit breaker went off, that means the transformer failed or its a shit spec.

[Uncle Bob]

I have a WES81 230V version and it has a IEC power connector with integrated fuse. So do they only use a primary fuse on the 80 watt model and not on the 50W? Or do they only use a fuse on the 230V model and not on the 110V? Is it only fused for the EU market? 

Someone on Youtube said their EU unit does not have a fuse, but I have yet to see actual visual evidence of this.

I'm new here but I am trying to upload a picture of the inside of my WE1010 bought here in Sweden in October.

Thanks. Any fuse further in the primary wiring?

No, nothing that I can see.

[alxpo]

yea and whats gonna break the circuit? A circuit breaker. Or a mains fuse. How is that acceptable?

How do you ensure the transformer will not go full short circuit? The EEVBLOG circuit breaker went off, that means the transformer failed or its a shit spec.

An inherently protected transformer meets isolation requirements also under overload conditions (sections 31-33 of the UL) so it will not be short-circuited.

But here we have of course the question about the range of potential misuses.

[Fungus]

An inherently protected transformer meets isolation requirements also under any overload conditions so it will not be short-circuited.

This one might be inherently protected at 110V, which is why they didn't put in a fuse.

The problem is that Weller didn't say that in their response. If they'd said that and promised to put a "110V only" sticker next to the power inlet on future models then this thread wouldn't exists.

They didn't do that though, they fobbed Dave off with a bunch of non-specific twaddle that shows that the person who wrote it didn't even watch the video.

What probably happened is this:

Some manager heard about the original video, asked an engineer about it and was told, "He's a test gear reviewer who accidentally plugged a 110V unit into 240V and the smoke came out".

The manager then writes "Sir" a letter offering to send him a 240V unit to review, imagining he's giving good customer service and promoting the Weller brand, but totally missing the point of the video.

The message was Lost in Translation.

[psatu]

But how come you still have this station on your recommended soldering gear list (https://kit.com/EEVblog/soldering-equipment)!  Even twice on the same list!

And actually I was about to buy myself a one some time ago but was put off largely because of your comparison review with the Hakko FX888D!

If I recall right the Weller didn't do very well on the tests. Or maybe the comments were just negative.

And more over the Pace ADS200 review won me over buying that instead. Or maybe more likely the follow up chat of the review.

Actually already received a one but is was some used demo unit and the tips too were used.

So returned it and now waiting for a new unit to arrive, hopefully with a new FW 1.4 inside 

[goaty]

From what I read, Weller is now just a brand of Apex Tool Group,
so maby the quality isn´t the same as the earlier products...
Just a thought.

[TheDane]

Someone questioned Weller and got a more detailed reply from a product engineer (specific to Australian supplied units).
Guess he didn't get the "don't say anything" memo:

Thank you for contacting Apex Tool Group.
<cut>
None of the hand held line voltage soldering tools have fuses
<cut>

That explains the bad feelings I've always had when using Weller, and why I have had it for so long 

I wonder why (not really  ) there is not much info regarding CE/cUL certification in the reply Dave.
Since the products is UL approved/recognized, the product is essentially not allowed to catch on fire. I have done a lot of type test certification work, and performed UL tests for electrical shorts, open, etc. in circuit. Every once in a while a rep from UL would show up and demand testing of whatever the rep deemed a safety concern or of interest. We used gaze to test for ignition, and it could ignite even without the main component shooting out flames.
https://services.ul.com/service/flammability-testing/

Will it catch on fire or 'just' smoke until mains is removed or the short has 'fixed' itself .
I am thinking a surge test (lightning strike) while powered on would be a great place to start. A bunch of positive/negative repetitive pulses might weaken the enamelled wire, causing a short?
I only have a 110V and a  220V handheld unit (now truly 'grounded' from usage  - was also missing in the first place), so I can't test for myself. Anybody?

It would also be quite interesting to know exactly which norm (CE/EN/UL) it was testet up against, though I am a practical engineer - not a laywer engineer.
If it is only to be used in certain conditions, I would REALLY like to know before I or others use it. I don't care if laywers fight in court, especially if I am in my grave, dead. (Say an utility fault where the mains live neutral suddenly has going missing - and mains voltage is now phase-phase, or 220V instead of 120V)

Thanks!

[Mr. Scram]

Is it actually that much of a problem? I agree it'd be better to have a fuse on there and other Weller products actually do, so even they seem to agree. Considering the widespread use of the products that don't have a mains fuse and the apparent lack of problems so far, is it really enough reason to not buy the product or consider it inherently unsafe?

[drussell]

A fuse is not required on small transformers like this.  The primary winding wire is small enough that it is allowed to be the "fuse" in a severe malfunction fault condition.  Standard (non-switching) wall warts are like this as well.  They tend to be designed to be short circuit proof simply by being impedance limited, they simply can't draw enough power to burn up in normal operation but a fault like shorted turns, connection to completely the wrong voltage or even the nasty square wave that comes out of cheap inverters will blow the winding open.  They are contained within housings that are either metal or plastic that is (supposed to be) flame retardant enough to not burst into flames and burn down completely before the winding blows up and opens the circuit.  Of course, I'm not sure that today's typical chinesium-grade plastic is as flame retardant as it should be but Weller doesn't need to put a fuse in there (though it is obviously a good practice) and I doubt it would actually burst into flames with any input voltage.  It might fill your lab with smoke to remind you of your blunder if you leave it plugged in, of course, though!   

A fuse won't always prevent smoke from a device anyway.  For example, a typical computer power supply will happily pump out 500 watts of 12 volts without going into overload protection.  You can get a whole lot of smoke out of something connected to one of those babies while it is still perfectly within it's input fuse range and output protection.  Should every device, perhaps every chip even, connected to it be required to have a fuse just in case there is a malfunction that might produce smoke? 

If I connect something that is rated for 120 volts to 1000 volts, it is going to fry.  Probably more quickly than on 240 volts.  Maybe with more smoke, maybe a quick death and less.  There will be some sweet spot on most devices (often even with a fuse) where it is likely to go into thermal runaway meltdown at some particular input voltage or fault condition.  That's what enclosures are for.  A fuse does not 100% stop components from emitting smoke. 

If they were regularly actually bursting into flames, I would be concerned, but a PEBKAC on Dave's part doesn't instantly make the device itself inherently dangerous.  This is why things like actual UL listing (unlike Batterizer's UL tests) do things like take a blowtorch to your product, to see what would happen when someone puts a 15A fuse in your 1A fuse holder.  Does the enclosure actually stop the flames?  What happens when we put 5000 volts on it?  Does it remain "safe" per the standards, even though the device doesn't survive, etc., etc.

[coppercone2]

whats going to short out at 450W and current limit itself? :wtf

parts are just gonna fail to a happy impedance like that? its probably gonna trip. What part is going to make plenty of smoke like a giant transformer winding dissipating 500W @ 0.3 ohms on a 12V rail?

[Mr. Scram]

A fuse is not required on small transformers like this.  The primary winding wire is small enough that it is allowed to be the "fuse" in a severe malfunction fault condition.  Standard (non-switching) wall warts are like this as well.  They tend to be designed to be short circuit proof simply by being impedance limited, they simply can't draw enough power to burn up in normal operation but a fault like shorted turns, connection to completely the wrong voltage or even the nasty square wave that comes out of cheap inverters will blow the winding open.  They are contained within housings that are either metal or plastic that is (supposed to be) flame retardant enough to not burst into flames and burn down completely before the winding blows up and opens the circuit.  Of course, I'm not sure that today's typical chinesium-grade plastic is as flame retardant as it should be but Weller doesn't need to put a fuse in there (though it is obviously a good practice) and I doubt it would actually burst into flames with any input voltage.  It might fill your lab with smoke to remind you of your blunder if you leave it plugged in, of course, though!   

A fuse won't always prevent smoke from a device anyway.  For example, a typical computer power supply will happily pump out 500 watts of 12 volts without going into overload protection.  You can get a whole lot of smoke out of something connected to one of those babies while it is still perfectly within it's input fuse range and output protection.  Should every device, perhaps every chip even, connected to it be required to have a fuse just in case there is a malfunction that might produce smoke? 

If I connect something that is rated for 120 volts to 1000 volts, it is going to fry.  Probably more quickly than on 240 volts.  Maybe with more smoke, maybe a quick death and less.  There will be some sweet spot on most devices (often even with a fuse) where it is likely to go into thermal runaway meltdown at some particular input voltage or fault condition.  That's what enclosures are for.  A fuse does not 100% stop components from emitting smoke. 

If they were regularly actually bursting into flames, I would be concerned, but a PEBKAC on Dave's part doesn't instantly make the device itself inherently dangerous.  This is why things like actual UL listing (unlike Batterizer's UL tests) do things like take a blowtorch to your product, to see what would happen when someone puts a 15A fuse in your 1A fuse holder.  Does the enclosure actually stop the flames?  What happens when we put 5000 volts on it?  Does it remain "safe" per the standards, even though the device doesn't survive, etc., etc.

The housing of the Wellers I know has been made out of proper "tool grade" PA6, but I'm not sure about this cheaper range of products. Maybe Dave could inspect the housing for markings and let us know?

[coppercone2]

A fuse is not required on small transformers like this.  The primary winding wire is small enough that it is allowed to be the "fuse" in a severe malfunction fault condition. 

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

your  not supposed to blow breakers. your not supposed to shut down an entire work bench and possibly room lights and smoke the joint up because of a 50 cent part. whoever designed this standard is a fucking moron

its unacceptable in a laboratory regardless. trash . What am I gonna do call building maintenance in a high end facility because of a 50 cent part? lose a room to smoke for 3 days? (who would make their employees  or students work in that smell??) NO.

you know what happens when you make a bunch of smoke at work? people think you are a fucking clown

[Ice-Tea]

your  not supposed to blow breakers. your not supposed to shut down an entire work bench and possibly room lights and smoke the joint up because of a 50 cent part. whoever designed this standard is a fucking moron

They were drafting an electrical safety standard. Not a convenience standard.

[coppercone2]

your  not supposed to blow breakers. your not supposed to shut down an entire work bench and possibly room lights and smoke the joint up because of a 50 cent part. whoever designed this standard is a fucking moron

They were drafting an electrical safety standard. Not a convenience standard.

tripping a breaker is a safety issue. so is toxic smoke.

you got a double wammy with that piece of shit. its devoid of common sense.

[TheAmmoniacal]

Anyone able to find the manufacturer of this transformer? Someone should buy a pair, plug it into 230/240V outside with and without a fuse just to demonstrate the difference $0.2 makes. Photonicinduction style?

[coppercone2]

yea i wanna see this tested with and without a fuse on a proper 240v line thats low impedance with a bypassed breaker, feeder breaker only at 50 or 100A

[TheAmmoniacal]

yea i wanna see this tested with and without a fuse on a proper 240v line thats low impedance with a bypassed breaker, feeder breaker only at 50 or 100A

With the station placed next to your jar of rubbing alcohol-soaked tissues.

[Fungus]

Anyone able to find the manufacturer of this transformer? Someone should buy a pair, plug it into 230/240V outside with and without a fuse just to demonstrate the difference $0.2 makes. Photonicinduction style?

What we really need is another one of these and not pull the plug after six seconds. See what happens if it's left alone.

They were drafting an electrical safety standard. Not a convenience standard.

This thread has nothing to do with "standards", it's here because:

a) Weller should know better than to sell an unfused device that could easily end up in a different country in 2018 (eg. ebay has been around for over 20 years).

b) The letter they wrote was pathetic. Clearly written by some management type using third-hand information.

Anybody quoting standards at each other has clearly missed the main point: Weller knows better than to do this, but didn't.

[drussell]

whats going to short out at 450W and current limit itself? :wtf

parts are just gonna fail to a happy impedance like that? its probably gonna trip. What part is going to make plenty of smoke like a giant transformer winding dissipating 500W @ 0.3 ohms on a 12V rail?

You've really never seen anything fail in a way that was not a direct, low-impedance short?   

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

Wait...  What?  Who blew what breaker now?   

[TheDane]

Anyone able to find the manufacturer of this transformer? Someone should buy a pair, plug it into 230/240V outside with and without a fuse just to demonstrate the difference $0.2 makes. Photonicinduction style?

Anyone able to find the responsible manager(s)? Someone should fire up that board instead.

[Fungus]

PS: Does anybody know why these things even use old iron transformers instead of switch-mode supplies?

It's just a simple 12V heating element (or 24V, or whatever).