EEVblog #1160 - Weller Responds

[Mr. Scram]

A large part of what you pay for in professional tools is that the quality is consistent and that you don't have to expect to fiddle with it to make it work. Considering the large amount of threads on modifying the TS80 and TS100 devices, you need to tinker with it quite a lot to get it going. If you don't value your time and don't have to worry about production being backed up and costing money, that's fine. If your hours cost real money and contracts can't be fulfilled, that's a risk you cannot take. In general, the price you pay for cheap devices is having to faff around.

[fsr]

This is very simple: this thing can potentially burn your house if a power surge damages the transformer. A simple fuse prevents that. Who in the world desings a mains-connected equipment that doesn't have at least a fuse inside on the PCB, or something like that?

In any case, you don't want to draw unlimited power from the grid. Bad things will happen.

[Mr. Scram]

This is very simple: this thing can potentially burn your house if a power surge damages the transformer. A simple fuse prevents that. Who in the world desings a mains-connected equipment that doesn't have at least a fuse inside on the PCB, or something like that?

In any case, you don't want to draw unlimited power from the grid. Bad things will happen.

Will it draw unlimited power, though?

[cdev]

It didn't draw enough power to pop the breaker. Just enough to start to burn itself up.

Which as people have pointed out, isnt super surprising when it was powered with twice the voltage plus a lower frequency. However, it really should have been fused for that and the other reason that its a frigging soldering iron.

[Mr. Scram]

It didn't draw enough power to pop the breaker. Just enough to start to burn itself up.

Which as people have pointed out, isnt super surprising when it was powered with twice the voltage plus a lower frequency. However, it really should have been fused for that and the other reason that its a frigging soldering iron.

Would a fuse have saved it? Remember that fuses for the wrong voltage tend to be twice the rated current of what they should be.

[glarsson]

Would a fuse have saved it? Remember that fuses for the wrong voltage tend to be twice the rated current of what they should be.

The iron in that cheap transformer saturated and the current was more than twice what it would have been with the correct transformer.

[Mr. Scram]

The iron in that cheap transformer saturated and the current was more than twice what it would have been with the correct transformer.

How much more? Because a little over twice is probably not enough to blow the fuse.

[cdev]

At 240v 50hz an included fuse intended for 120v 60 Hz operation quite likely would have popped because the current draw would also have been higher.

It didn't draw enough power to pop the breaker. Just enough to start to burn itself up.

Which as people have pointed out, isnt super surprising when it was powered with twice the voltage plus a lower frequency. However, it really should have been fused for that and the other reason that its a frigging soldering iron.

Would a fuse have saved it? Remember that fuses for the wrong voltage tend to be twice the rated current of what they should be.

Also, I bet the email Dave got from them was written by an AI. Shows how crappy customer service is becoming a lot of the time.

[Mr. Scram]

At 240v 50hz an included fuse intended for 120v 60 Hz operation quite likely would have popped because the current draw would also have been higher.

That was the point. The current rating of a 120V fuse tend to be much higher than that of a 240V fuse. Not to mention the inrush current, for which the fuse is also specified.

[fsr]

This is very simple: this thing can potentially burn your house if a power surge damages the transformer. A simple fuse prevents that. Who in the world desings a mains-connected equipment that doesn't have at least a fuse inside on the PCB, or something like that?

In any case, you don't want to draw unlimited power from the grid. Bad things will happen.

Will it draw unlimited power, though?

Well, it didn't but potentially it could "try to", if left alone and continuing melting and overheating. Sooner or later, it would trip a breaker, but the soldering station could be on fire by then.

[glarsson]

The iron in that cheap transformer saturated and the current was more than twice what it would have been with the correct transformer.

How much more? Because a little over twice is probably not enough to blow the fuse.

Much higher. When the core saturates it no longer behaves as an iron core and the primary winding basically becomes air cored. The only thing limiting the current is the much smaller inductance of the air cored primary and the resistance of the wire. This current will quickly destroy the primary unless a fuse interrupts the current.

[timelessbeing]

this thing can potentially burn your house

You are talking out of your arsehole.

its particularly distressing that what amounts to a name brand - Weller - a brand we have all recommended to new buyers as almost certain to be safe

Where is your proof that it is unsafe?


If you plugged 240V into my house right now, probably half my appliances will go up in smoke. My ikea lamp, my kettle etc. etc....

You people need to stop shitting your pants when you see a puff of smoke and go outside once in a while.

[Robaroni]

I've had both, the Chinese cost me a few hundred bucks, not even that cheap, the iron cord twisted on it one day and blew the circuit board out.
If you're a hobbyist, fine by all means buy cheapo stuff but don't think it comes up to the level of Keysight.

I don't know any Chinese brand irons costing few hundred bucks, so I presume you meant a Chinese made international brand one. Then that must be a Metcal.
I have a Metcal died for no reason, and I'm aware it's not visually appealing on the internals since I've also tried to fix mine.
But people don't buy a Metcal for reliability or quality. They buy a Metcal for the performance

Inductive heating gives superb thermal recovery, better than all stations in the same price range.
I keep three stations for small, medium and large jobs. A $1400 JBC Nano with tips, a $700 Metcal with tips and tweezers, and a $1200 JB Heavy Duty with tips.
That's how I rank Metcal in terms of performance, and you can see the value of the Metcal compared with much more expensive competitors.

As for Keysight, just search the word "Keysight" posted by me, and see how they fail repetitively. Here's a brief list of Keysight fails on my limited collection of Keysight gears:
1. MSOX3104A, failed to boot, NAND corruption, sent to repair once.
2. MSOX6004A, booted fine but randomly crashes, sent to repair once, reflashed by myself twice.
3. MSOX6004A, power supply made hiccup overcurrent noise, sent to repair. This is the fourth fail of the same unit within 2 years.
4. MSOX6004A, came with DOA logic probe, new in box.
5. U1461A, came with two sets of DOA ultra-fine probes.
6. U1461A, tried to kill me with a faulty input mux. Probes were at high voltage, displays 0V, unit replaced.
7. U1620A, CH1 had ~0.2 div bias regardless input range, replaced.

May I remind you that those are not cheapo. The MSRP combined, with software options I have, sums up to $70k.
Putting my tin foil hat on, I even think those are just FUD movements by KS to force their customers to buy warranty extension services.
I know it is not, since the stupid NAND problem is actually under free repair regardless of warranty, but still it's not good impression.
Luckily, Daniel and other kind people from KS are extremely helpful, but that's only in US. I've heard news from India and Saudi Arabia that the service there are not nearly as good as it is in the US. So it's a YMMV thing.

So you had better luck with cheapo stuff?

[floobydust]

It's likely Weller thinks they did nothing wrong.

Weller submits a new soldering station to UL for approvals as they have been doing for decades prior. It gets assessed to UL 499 like all previous North American soldering irons.
Not IEC 60335 for Europe, not UL 60335 (which is IEC 60335 with USA particulars).

Vintage safety standard UL/ANSI 499 (87 years old) is for Electric Heating Appliances. A real mix of products-  up to 15kW steam-bath generators, soap kettles, reptile tank heaters, heat guns, hot glue guns, ceramic kilns and more.

All are directly mains-powered heating elements, no step-down transformer is considered, even in the soldering gun clause. The mains breaker is considered the protective element, as it would be in say a 10kW heater. I would say UL 499 is weak in some areas, like a component (power transformer) burning up. It's not calling for a fuse, or an approved transformer, or a fault test there. The standard says it must be grounded but no spec or test on fault current, wire gauge etc. I could go on, but it seems this standard is full of holes.

An "engineering" boss I had used to say "it's meeting the requirements" and when I demanded to add a fuse he'd say "where is it a requirement, show me".
I put the fuse in anyway as I had to under the code of ethics as an engineer and "good practice". A non-engineer or marketing type for an engineering boss has no rights to command or instruct there.

[cdev]

Where is your proof that it is unsafe?

I didn't say that.

[fsr]

Let's put it this way: it's a 70w station. It will draw like 600 mA at 120v. Instead of putting a fuse, and be safe from any random fault, you don't put a fuse, and just rely on tripping a breaker that could at the very least have 10A on a 220v system, and i assume double of that on a 120v system. WTF kind of engineering is that?

[timelessbeing]

70W won't even toast your bagel.

Assuming the worst case, and the transformer gets the full 2000W, how long do you think the 30AWG wire will last?

[tszaboo]

70W won't even toast your bagel.

Assuming the worst case, and the transformer gets the full 2000W, how long do you think the 30AWG wire will last?

You can blow up stuff with 1W of power with the right conditions.

So melting a PSU is safe and approved?

Should I post it again?

I like the safety stand.

It could be plugged into an IEC plug, so 16A and 240V could go into the box. This is not a USB charger or a clapping monkey. This is a instrument to be used in a professional environment. When they decided that it will get grey color, and not red, they made this statement.
It is for professional environment, where people go to make money. Downtime, fire drill, debugging why your instrument doesnt work > this all cost money. So I damn well expect them to do everything in their power to avoid  AC/DC smoke effects. Especially if they splattered safety a dozen times on their product page.

And they better not just make their station "compliant with standard" but use all reasonable methods to make sure the thing doesnt blow up in my face, or I dont electrocute myself with it.

[timelessbeing]

You can blow up stuff with 1W of power with the right conditions.

That would be a feat. Please explain.

Actually, you can choke on your muffin for 0W.

It could be plugged into an IEC plug, so 16A and 240V could go into the box

You have 3800W available in a standard outlet shape? That's a bit worrisome. At least the iron would suffer a quicker, more humane death.

[eugenenine]

So melting a PSU is safe and approved? mmmm thanks I did not know.

Thats not what I said.  It performed just as the UL test said, it didn't burn down his house.

Anyway that smoke out from the Weller could have triggerd a smoke detector... you know what can happen next.

I know exactly what happens next, someone gets annoyed by the beeping and has to disable the smoke detector

[fsr]

70W won't even toast your bagel.

Assuming the worst case, and the transformer gets the full 2000W, how long do you think the 30AWG wire will last?

Well, that's what Weller says, that this is a 70W station. Here they say 85W, so it seems like the soldering iron is 70W, and the consumption is 85W: https://weller-tools.com/we1010na/

The thing is that the transformer won't die immediately. As you can see in the video, it will start burning itself from excess power dissipation, and while it burns it will short it's windings, until someone notices and pulls the plug, or it trips a breaker.

The breaker has like 20 times the current rating of the fuse that the soldering station should have. Do we really need to discuss what is safer and why?

[Muttley Snickers]

Anyway that smoke out from the Weller could have triggerd a smoke detector... you know what can happen next.

I know exactly what happens next, someone gets annoyed by the beeping and has to disable the smoke detector

More than that, in a commercial environment it could cost you thousands of dollars for a fire brigade attendance, the adjoining businesses would also be required to evacuate the building losing time and money as well and no doubt giving you a bad reputation with the neighbours, and for what?, the lack a ten cent fuse.   

https://www.eevblog.com/forum/blog/eevblog-1160-weller-responds/msg2048764/#msg2048764
https://www.eevblog.com/forum/chat/pull-in-case-of-fire!/msg707589/#msg707589

[timelessbeing]

that this is a 70W station. Here they say 85W,

Oh well that changes everything!

As you can see in the video, it will start burning itself

The video I watched showed some crusty wires.

it will short it's windings, until someone notices and pulls the plug, or it trips a breaker.

Or it goes pop. Have you ever pumped a bunch of current into a thin copper wire? I don't think you have.

. Do we really need to discuss what is safer and why?

I don't know. Aren't you discussing it right now?

Personally I think the station would have been more dangerous if it was working.

[timelessbeing]

and for what?, the lack a ten cent fuse.   

For some ding dong who doesn't know what he is doing. The fuse didn't cause it.

[jonovid]

before Dave's shocking discovery, I trusted the Weller name. 
having seen it, in electronics magazines for yrs. as a sign of safety , reliability & quality used by the professionals.
sad to see this is no longer true!