Author Topic: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix  (Read 51105 times)

0 Members and 1 Guest are viewing this topic.

Online amyk

  • Super Contributor
  • ***
  • Posts: 8240
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #25 on: November 24, 2013, 06:19:15 am »
It could be considered bad design, but is this really a safety issue? This is a grounded equipment so if it has been properly grounded any shorts will just divert current into ground and not present a shocking potential to the operator.

0.3mm is enough to withstand ~900V in free air between two conductors, let alone one which has been covered in soldermask. So I wouldn't say this is particularly worrying (compared to e.g. certain Chinese mains adapters where a fault can be hazardous.)
 

Offline Towger

  • Super Contributor
  • ***
  • Posts: 1645
  • Country: ie
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #26 on: November 24, 2013, 09:12:30 am »
The French love their electronics, but French electronics come with a French attitude. I wish you luck getting much of a response from them. 
For instance look at Renault, they pack their cars with electronics as standard, but refuse to believe that very common hardware faults are design faults. They will just sell you expensive replacement modules which last a couple years before failing. Even after years of coil, window regulator, key card, dash display problems they don't learn. One popular model got such a bad name it is no longer sold into UK and Ireland. All for the sake of listening to feedback and fixing a few small problem in otherwise reliable cars.
 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #27 on: November 24, 2013, 12:57:29 pm »
It could be considered bad design, but is this really a safety issue? This is a grounded equipment so if it has been properly grounded any shorts will just divert current into ground and not present a shocking potential to the operator.

0.3mm is enough to withstand ~900V in free air between two conductors, let alone one which has been covered in soldermask. So I wouldn't say this is particularly worrying (compared to e.g. certain Chinese mains adapters where a fault can be hazardous.)

There in no silkscreen covering the ground plane on the right side of the pads. Any moisture will cause arcing. About safety, not always sockets are properly grounded. In my flat there is no ground at all. I use central heating radiator as the  grounding source as it is best I can get.
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 26755
  • Country: nl
    • NCT Developments
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #28 on: November 24, 2013, 01:45:08 pm »
That little bit of visible copper is a problem. If they had the solder mask continue up to the pad everything would have been OK with a very thin margin. I'd also fix the grounded outlet problem in your flat. Pulling in an extra wire may be less work then you'd expect.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #29 on: November 24, 2013, 02:23:27 pm »
I'd also fix the grounded outlet problem in your flat. Pulling in an extra wire may be less work then you'd expect.
If there would be a place where to connect it. Whole building should be rewired and I only rent this flat. I "fixed" it in one room, but that is more for the ESD purposes. Actually it should be pretty good ground. But whatever, it is not about my problems but how CIF screwed up.
 

Offline megajocke

  • Regular Contributor
  • *
  • Posts: 191
  • Country: 00
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #30 on: November 24, 2013, 04:52:10 pm »
I hope you are only using it to discharge ESD, otherwise faults in your equipment could be very dangerous to people working on the pipes or people in other apartments. The grounding impedance may not be low enough to ensure protective devices (fuses/breakers) cut off power quickly enough.

I don't know what is common in Latvia, but here in Sweden you always have usable ground in your fuse box/breaker box even if there are no grounded outlets anywhere. The feed to the fuse box is commonly done with ground and neutral on a shared "PEN" conductor plus one or three phases of 230 V to ground/netural. Newer installations may use a grounding conductor separate from the neutral, but it is quite uncommon. After the fuse box, ground and neutral is always separated.
 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #31 on: November 24, 2013, 05:24:19 pm »
This building was built in Soviet times with ensuing consequences. I do understand really well that this is bad thing to do. I have put there resistor in series. As much as I know, real ground is aviable only on the first floor and I live on fifth. Fuse box have only neutral and it can be easily swapped with live if not smart enough electrician will do something there as all wires are the same white color. And even this fuse box is about 30m 20m away from the door of my apartment.
« Last Edit: November 25, 2013, 02:00:45 pm by wraper »
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 16272
  • Country: za
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #32 on: November 24, 2013, 05:48:31 pm »
You mean with the bolt fuses as well?
 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #33 on: November 24, 2013, 06:00:36 pm »
Took a photo.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 16272
  • Country: za
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #34 on: November 24, 2013, 06:42:43 pm »
Almost as bad as Jondolo wiring here, at least you have fuses, and insulation. When you have track lighting from the glow of the bare wires threaded through trees, walls, whatever with earth return you know there is a problem.
 

Offline M. András

  • Super Contributor
  • ***
  • Posts: 1014
  • Country: hu
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #35 on: November 24, 2013, 07:16:41 pm »
i counted 2 burned wires, and seems like there is a third under a fuseholder, these installation should be replaced by the utility company to prevent electrical fires ffs
 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #36 on: November 24, 2013, 07:35:11 pm »
Those wires are aluminium, don't know if burned wires are actually used but likely are. There are 3 fuse holders for each apartment but for my apartment third is broken but yet I have voltage in all sockets. Frankly I try to not think about wiring as it makes me sad. If I owned apartment then I likely would invest in it. I have an idea, I'll check with my Flir i7 what's going on there.
« Last Edit: November 24, 2013, 07:45:44 pm by wraper »
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 16272
  • Country: za
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #37 on: November 24, 2013, 07:45:03 pm »
Public rental housing often had very minimal electrical ( often none or only when what is visibly broken inside the unit is eventually repaired as cheap as possible) maintenance and this is likely to be left until it either fails totally or causes a fire.
 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #38 on: November 24, 2013, 07:54:08 pm »
Nothing incredibly hot (max 26 C) but I'm concerned about warm fuse holder and wire from it on the right side as it is mine. And I consume less than 500W right now.
 

Offline Paul Moir

  • Frequent Contributor
  • **
  • Posts: 926
  • Country: ca
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #39 on: November 24, 2013, 08:01:33 pm »
It could be considered bad design, but is this really a safety issue?

You're not supposed to rely on your safety system in a safe design, your principal design should be inherently safe.  It's there for when unlikely things go wrong.  A 0.3mm space of air presents a not unlikely current path to the case:  you get a small power line spike and now what's the voltage needed to sustain an arc?

I am not an EE, but I don't think one would ever intentionally rely on solder mask for safety.  It seems like there is too much to go wrong there easily.
 

Offline NiHaoMike

  • Super Contributor
  • ***
  • Posts: 8973
  • Country: us
  • "Don't turn it on - Take it apart!"
    • Facebook Page
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #40 on: November 24, 2013, 09:35:11 pm »
You're not supposed to rely on your safety system in a safe design, your principal design should be inherently safe.  It's there for when unlikely things go wrong.  A 0.3mm space of air presents a not unlikely current path to the case:  you get a small power line spike and now what's the voltage needed to sustain an arc?
How is that any different from a MOV or other surge protector device from hot to ground?
Cryptocurrency has taught me to love math and at the same time be baffled by it.

Cryptocurrency lesson 0: Altcoins and Bitcoin are not the same thing.
 

Offline tom66

  • Super Contributor
  • ***
  • Posts: 6680
  • Country: gb
  • Electronics Hobbyist & FPGA/Embedded Systems EE
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #41 on: November 25, 2013, 10:57:12 am »
Those devices are designed to fail open, not short. Class Y rated capacitors too.
 

Online amyk

  • Super Contributor
  • ***
  • Posts: 8240
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #42 on: November 25, 2013, 12:39:25 pm »
Schematic (block) in the manual is dated 2005. The most recent date on the parts in my unit 12 44. So it might be selling 7-8 years.
And, all this time, has anyone managed to find reports of sudden failure, shock, etc. ...? Unless they changed the PCB (or the board house messed up somehow)...

But you should definitely fix the grounding in your house. This is a very good example of why grounded equipment should be used with a grounded supply.
 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #43 on: November 25, 2013, 01:06:45 pm »
Schematic (block) in the manual is dated 2005. The most recent date on the parts in my unit 12 44. So it might be selling 7-8 years.
And, all this time, has anyone managed to find reports of sudden failure, shock, etc. ...? Unless they changed the PCB (or the board house messed up somehow)...
Don't know how such situations were handled if they occured. What I know that I have seen about 1 mm gaps shoot through under about 300V voltage. For example between pads of primary electrolytic capacitor in phone chargers. I checked that fuse box actually have in it what supposed to be earth (with white cables again as all of the wiring). But this barely makes wiring job any easier. Nobody will allow me to put earth cable on the wall in the public corridor therefore that means it needs to be mounted in the concrete wall 20m long until it reaches my apartment at all.
« Last Edit: November 25, 2013, 01:23:56 pm by wraper »
 

Offline dfmischler

  • Frequent Contributor
  • **
  • Posts: 548
  • Country: us
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #44 on: November 25, 2013, 01:43:11 pm »
An MC68hc908 is an 8/16 bit 6809 family not 68K so even earlier than mid 80's.
Um, that processor has the 6805 architecture.  So it is far less capable than the 6809.
 

Offline ElectroIrradiator

  • Frequent Contributor
  • **
  • Posts: 614
  • Country: dk
  • More analog than digital.
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #45 on: November 25, 2013, 06:36:32 pm »
Newer version in my manual.
...and that is the 'China Exports' symbol, not the CE mark from the EU. 'Amazingly' similar, except for a slight geometric difference. On the genuine CE mark, the circumference of the C just intersects the leftmost point on the E.

 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #46 on: November 25, 2013, 09:58:36 pm »
Don't think that this CE mark on HD6950 graphics card is fake. AMD unlikely would fake it. Actually amazingly high product count (from reputable manufacturers) have CE mark applied with wrong gap and gemetry.
 

Offline Monkeh

  • Super Contributor
  • ***
  • Posts: 7990
  • Country: gb
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #47 on: November 25, 2013, 10:03:26 pm »
Newer version in my manual.
...and that is the 'China Exports' symbol, not the CE mark from the EU. 'Amazingly' similar, except for a slight geometric difference. On the genuine CE mark, the circumference of the C just intersects the leftmost point on the E.

ffs, will this stupid myth never die?
 

Offline wraperTopic starter

  • Supporter
  • ****
  • Posts: 16796
  • Country: lv
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #48 on: November 25, 2013, 10:07:17 pm »
Wrong CE from Tefal. So ugly CE mark means almost nothing itself.
 

Offline Bored@Work

  • Super Contributor
  • ***
  • Posts: 3932
  • Country: 00
Re: Deadly insane design (CIF FT 02 reflow oven) Teardown - rant - safety fix
« Reply #49 on: November 25, 2013, 10:53:31 pm »
Wrong CE from Tefal. So ugly CE mark means almost nothing itself.

How could it? The CE mark as such means nothing, ugly version or not.
I delete PMs unread. If you have something to say, say it in public.
For all else: Profile->[Modify Profile]Buddies/Ignore List->Edit Ignore List
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf