Grounded soldering Iron or Ungrounded? (EU Plug) - Page 1
Forum section: electronics / beginners

author: 22khz
author_rank: Newbie
timestamp: January 26, 2018, 12:50:08 am
content: Hello, I need your advice yet again.I was Browsing Amazon UK, I stumbled across a few wonderful soldering iron kits under the 25 EUR range, Including Magneto's Soldering pack, FIXKIT, and more.Naturally, this being a UK based store, it has most of the time the UK plugs, however it also has the grounded German "schuko" plugs, which are also present in my country.And, there are also ungrounded european plugs, having just line and neutral.Buying with an intent for electronic use, I'm deeply concerned about the discharge of static electricity, it could or will damage the electronic components that I'm working on.I have bought an anti-static mat, along with anti-static wrist strap, greatly reducing the risk of ESD, I also keep in mind about the environment and my clothing to further be safer from ESD.I have few Ideas:Buy a UK-plugged soldering iron, then use a UK-EU travel adapter.Look for a grounded European soldering iron, greatly reducing product availability.Look for an ungrounded European soldering iron, greatly reducing product availability,and probably increasing risk of static discharge.Buy a UK- Plugged soldering iron, then modify it to a European plug. (Should be possible because both use 240V 50hz)You could ask me, Why don't you buy from a local store?Well, there are few issues I'm having;They're more expensive, None of them has a toolkit, which is very convenient for mobility. And none of them has any handy tools, not even soldering tips.My sources are Amazon.co.uk, Amazon.de and last on the priority Ebay.Yes I'm not an idiot, ungrounded also means safety concerns about the user.

author: Ian.M
author_rank: Super Contributor
timestamp: January 26, 2018, 02:20:00 am
content: If you want to avoid damaging sensitive components like MOSFETs or any CMOS IC, and the iron has a mains voltage element, then a properly grounded bit is *ESSENTIAL*.If the bit isn't grounded the leakage current through the element's insulation when hot can be enough for you to be able to measure more than half the supply voltage on the bit with respect to ground, and if there is any ground connection to the board you are working on that *WILL* destroy any unprotected MOSFET gate.

author: 22khz
author_rank: Newbie
timestamp: January 26, 2018, 02:28:40 am
content: Quote from: Ian.M on January 26, 2018, 02:20:00 amHow can you tell if the tip is grounded by looking the images?

author: Monkeh
author_rank: Super Contributor
timestamp: January 26, 2018, 02:32:14 am
content: Quote from: 22khz on January 26, 2018, 02:28:40 amYou can't.Buy a known quantity, not a cheapy.

author: 22khz
author_rank: Newbie
timestamp: January 26, 2018, 02:38:38 am
content: There is one that markets itself as ESD Free, what's your opinion about it?click hereBy the way, if anyone has suggestions forelectronic useto avoid static damage, please let me know.

author: AllTheGearNoIdea
author_rank: Unknown
timestamp: January 27, 2018, 10:39:44 pm
content: I’m not sure if your working in a production environment but if your not just ignore all the ESD crap. I have worked in electronicss for +25 years and have yet to damage anything. Note I do take basic precautions but this is really not down to any particular type of equipment. If your working on mains powered equipment or mains powered soldering iron it should be Earthed.

author: tooki
author_rank: Super Contributor
timestamp: January 29, 2018, 12:01:44 pm
content: No, all you know is that you don’t know whether you damaged anything or not. Lots of ESD damage is subtle, like reduced longevity or reduced performance, but not immediate failure. This has been extensively studied. It’s almost guaranteed that you have caused subtle damage if you’ve been ignoring ESD measures.So to everyone else: no, it’s not “ESD crap”. You don’t have to go crazy, but ESD basics are a must even for the hobbyist, especially nowadays where everything is ICs.

author: jewelie
author_rank: Regular Contributor
timestamp: January 29, 2018, 12:55:06 pm
content: Quote from: Ian.M on January 26, 2018, 02:20:00 amDidn't know about this! Just jumped up and tested my old Antex XS25W and M12 irons. Both earthed. Phew!

author: Ian.M
author_rank: Super Contributor
timestamp: January 29, 2018, 01:19:59 pm
content: Seehttps://www.eevblog.com/forum/beginners/simple-fet-circuit-for-onewire-protocol-doesn't-work-as-expected/for a case of tip leakage current repeatedly blowing 2N7000 MOSFETs. You can skim down to reply #8 to get to the diagnosis.Its possible for a linear transformer isolated low voltage iron to have low enough leakage for an ungrounded tip not to be an issue, but anything with a SMPSU and an ungrounded tip should be regarded with deep suspicion.Another pitfall for the unwary: A grounded tip can cause major problems when working on boards with soldered in batteries - if you need to work on the battery circuit, remove *ALL* other connections to the board that could introduce a ground before touching it with the grounded iron tip.ESD precautions are *NOT* ignorable crap - ESD frequently degrades the performance of (and occasionally kills) CMOS ICs and other sensitive devices handled without due care. The key to avoiding damage is to avoid any discharge through the device, which, as the human body has a significant capacitance to ground, if you don't have the right equipment, is all too easy to cause when initially touching, picking up or putting down a part or board, or when passing it to someone else.

author: Tepe
author_rank: Frequent Contributor
timestamp: January 29, 2018, 02:04:09 pm
content: Quote from: tooki on January 29, 2018, 12:01:44 pmI don't disagree with this.Unfortunately, some of us hobbyists happen to only have outlets like this:

author: tooki
author_rank: Super Contributor
timestamp: January 29, 2018, 07:06:21 pm
content: Quote from: Tepe on January 29, 2018, 02:04:09 pmAside from the fact that I would argue that any ungrounded outlets need to be upgraded, grounding is not the only thing done for ESD protection. For example, making sure to use antistatic foam for IC storage, or even foam with aluminum foil on it in a pinch. Increasing humidity. Removing carpet.Besides, if you don’t have a ground wire, you still might have a radiator pipe or something to connect to?

author: Monkeh
author_rank: Super Contributor
timestamp: January 29, 2018, 07:29:27 pm
content: Quote from: tooki on January 29, 2018, 07:06:21 pmAnd you assume a radiator pipe will have a viable connection to earth why?

author: james_s
author_rank: Super Contributor
timestamp: January 29, 2018, 07:30:50 pm
content: Quote from: AllTheGearNoIdea on January 27, 2018, 10:39:44 pmThat's like saying just ignore seatbelts because you've been driving around without one for 25 years and haven't been killed yet.You don't have to go overboard with ESD protections but grounding the soldering iron is a pretty basic thing. I do actually know someone who was cursing junky Chinese ICs for a while, then realized there was a significant potential between his soldering iron tip and the ground of the power supply connected to the board he was working on. It was frying inputs on ICs he was soldering, power supply was off but it was still providing a return path.I have also damaged RAM modules presumably due to ESD. RAM was working, removed it and set it aside, then reinstalled it and RAM was defective. I cannot prove it was ESD, but if not then what else was it?

author: edgelog
author_rank: Regular Contributor
timestamp: January 29, 2018, 08:34:13 pm
content: Quote from: Monkeh on January 29, 2018, 07:29:27 pmExactly. Many years ago, a friend's wife got almost electrocuted when touching a water tap in the kitchen. After many hours of searching, we found that a neighbour had used a shared water feed pipe to ground a faulty light circuit.

author: Zero999
author_rank: Super Contributor
timestamp: January 30, 2018, 10:56:44 am
content: As far as I'm aware, the default for a soldering iron is for the tip to be earthed.If you don't have access to a grounded mains socket, then that's no problem for ESD. No earth connection is required for protection against static discharge. It's a myth. All that's needed is for everything to be at the same potential. Connect the earth conductor to an ESD safe mat and wrist strap. Wear the wrist strap and sit the board on the ESD mat and you won't have and ESD problems.

author: Ian.M
author_rank: Super Contributor
timestamp: January 30, 2018, 01:47:49 pm
content: However if you don't have a grounded wall outlet, your testbench and any nearby fixed metal objects need equipotential bonding, with all outlets on the bench 'grounded' to the equipotential bonding conductor, otherwise leakage currents from soldering iron elements and testgear with SMPSUs *WILL* blow sensitive components as I mentioned above in reply#9. Unfortunately, the permitted leakage currents from all the testgear and other equipment on you bench add together and if you have a lot of equipment, the total could be lethal, or if there is a fault elsewhere in the building, the metalwork you are bonding to could go live, so an equipotential bonding system or supplementary grounding should only be installed under the supervision of a fully qualified electrician familiar with the local regulations.

author: tooki
author_rank: Super Contributor
timestamp: January 31, 2018, 12:37:25 pm
content: Quote from: Monkeh on January 29, 2018, 07:29:27 pmBecause it’s better than nothing? We are talking about grounding a soldering iron tip here, not a light fitting...

author: Tepe
author_rank: Frequent Contributor
timestamp: January 31, 2018, 01:04:33 pm
content: Quote from: tooki on January 31, 2018, 12:37:25 pmIsn't it enough that your soldering tip and wristband are at the same potential?

author: Cliff Matthews
author_rank: Unknown
timestamp: January 31, 2018, 03:21:05 pm
content: Quote from: AllTheGearNoIdea on January 27, 2018, 10:39:44 pmFor the record, I still like his YouTube channelI saw him working with an ESD strap... So are you re-thinking ESD lately?https://youtu.be/mNsLj6gleQs?t=1447

author: Monkeh
author_rank: Super Contributor
timestamp: January 31, 2018, 03:34:25 pm
content: Quote from: tooki on January 31, 2018, 12:37:25 pmIt may literally be nothing. It also may introduce a dangerous potential.

author: AllTheGearNoIdea
author_rank: Unknown
timestamp: January 31, 2018, 04:36:11 pm
content: OK Cliff You got me there LOL!!!!In fairness this was a work project, so I take more care of other peoples IC investment than my own stuff. Anyway I promise to man-up in the future and not to bother with any of that ESD Bull Crap!Im still Laughing! Im a FAKE (Watch the Video)Regards Chris - AllTheGearNoIdeahttps://youtu.be/mNsLj6gleQs

author: johnkenyon
author_rank: Regular Contributor
timestamp: February 01, 2018, 10:34:53 am
content: Back in the day (about 30 years ago) I bought a 50v AC "electronic" soldering iron from RS, fed from the mains (240v with an earth at the outlet) via a 25-0-25 transformer.The soldering iron lead had an earth wire, and it was connected to the mains earth via a 1M resistor. (The metal case was connected directly to the mains earth)If I was wiring it today on a supply without an earth, I would connect the soldering iron earth via a 1M resistor to a isolated 4mm socket on the PSU case so that I could connect it the rest of my "equipotential ESD protected" area, whilst reducing the chance that a power supply fault could end up feeding 240v to my antistatic mat.You need the 1M resistor because "ESD protection" means electrostaticdischargeprotection - the 1M resistor means the charge is dissipated over milliseconds, rather than being discharged in a flash.By the way, the iron and PSU box are still working, with the only modification being the installation of a fused IEC inlet instead of the permanent flex.

author: Ian.M
author_rank: Super Contributor
timestamp: February 01, 2018, 05:54:20 pm
content: The problem is the element insulation resistance when hot can be expected to be significantly lower than 1Meg. If the tip isn't hard-grounded, the leakage current will build up enough voltage across your ESD discharge resistor to damage sensitive devices. *IF* its a low voltage iron, with a fully floating low leakage supply, you can get away with an ungrounded tip or even one with a 1Meg ESD resistor in series with its ground connection, but many PSUs have far too much leakage current for that to be practical.

author: Prehistoricman
author_rank: Regular Contributor
timestamp: February 02, 2018, 03:14:55 pm
content: Quote from: tooki on January 29, 2018, 07:06:21 pmmikeselectricstuff recently mentioned in a video that putting ICs in foil-wrapped polystyrene is a bad idea because... 31:23