Free floating soldering iron - Page 1
Forum section: electronics / testgear

author: iceisfun
author_rank: Regular Contributor
timestamp: December 11, 2013, 06:14:45 pm
content: I have a Hakko 888 digital and love the iron, its the best I've ever worked with.However I noticed (by accident) that it isn't floating, are higher end irons floating or is it normal for the iron to go to earth?

author: Dave
author_rank: Super Contributor
timestamp: December 11, 2013, 06:40:30 pm
content: AFAIK the tips are connected to mains earth through a high resistance.I'd have to check my Ersa with a multimeter to say for sure.

author: Neilm
author_rank: Super Contributor
timestamp: December 11, 2013, 06:47:08 pm
content: Most are connected to earth - it helps protect against ESD damage when you touch the pins on the IC.

author: uoficowboy
author_rank: Regular Contributor
timestamp: December 11, 2013, 06:51:54 pm
content: I definitely learned a number of years ago that the tip on a Weller WD1 station was grounded with very low resistance. That was a nice spark

author: Rufus
author_rank: Super Contributor
timestamp: December 11, 2013, 07:06:56 pm
content: Most standards require a low resistance between the iron tip and ground connection. MIL-STD-2000A for example states"Resistance between the tip of the hot soldering iron and the workstation ground shallnot exceed 5.0 ohms. The potential difference between the workstation ground and the tip of thehot soldering iron shall not exceed 2 millivolts RMS."A low resistance is most likely what you will get by default. Options to float or tie through a resistance may be provided.

author: AndersAnd
author_rank: Frequent Contributor
timestamp: December 11, 2013, 09:07:45 pm
content: Quote from: iceisfun on December 11, 2013, 06:14:45 pmThat feeling will only last until you try high end soldering stations from Metcal (and JBC I've heard too). So don't try these unless you can afford them.Quote from: iceisfun on December 11, 2013, 06:14:45 pmThe newer high end Metcal soldering stations with LCD display (MX-5000, MX-5200 and the new MX-500 coming out later this month) won't even heat up if the earth connection is missing. This is done as to avoid damaging components with EDS, if the earth wire is missing. You can't really tell this without measuring, so MEtcal decided to build in a fuction that automatically checks for this.New MX-500:http://www.metcal.com/Hand_Soldering_Systems/id-MX-500P/New_MX-500P_Power_SupplyQuoteNew MX-500 User's Manual:New MX-500 Soldering, Desoldering and Rework System User manual - Multi LanguageQuoteNotice the new MX-500 coming out this month is basically a MX-5000 including LCD and everything, but with half the output power (40 W vs. 80 W).The original MX-500 had no display but was also 40 W and this will run without earth connection.

author: M. András
author_rank: Super Contributor
timestamp: December 11, 2013, 10:26:18 pm
content: Quote from: uoficowboy on December 11, 2013, 06:51:54 pmi measured my wd1m with a wrmp iron once. somewhere between 1k and 100k dont really remember the exact number. but if plug is in it will be floating or connected to whatever you solder the plug

author: aargee
author_rank: Frequent Contributor
timestamp: December 11, 2013, 10:32:28 pm
content: If it is really important, you could use an isolating transformer with un-earthed output for the iron?

author: con-f-use
author_rank: Unknown
timestamp: December 12, 2013, 10:00:15 am
content: Higher end irons give the possibility to choose at what potential the tip is (e.g. via a jack at the backside):- Iron floating (increasing possibility of static shock)- Iron hard grounded (directly connected to ground - bad for soldering in life-circuits as you can easily short stuff)- Iron soft grounded (connected to ground via an 1MOhm+ resistor - reduced shortciruit damage, static electricity fades slowly)- Iron referenced to some other potential via jack (not sure when you'd want that)They also warn you if ground connection is missing.Most common in cheap irons is hard grounding without check.

author: eV1Te
author_rank: Regular Contributor
timestamp: December 12, 2013, 02:00:23 pm
content: I am surprised that most standards require hard grounded tip, I mean all the ESD mats/tools we use, have 10 Mohm+ just so that a charged component cant short to ground and become damaged.The soldering iron seems to be an exception to that rule?

author: Kjelt
author_rank: Super Contributor
timestamp: December 12, 2013, 02:10:39 pm
content: On the new Weller Dx station I got you could choose which you wanted, floating, softgrounded or hardgrounded. Very nice.I think if you have an ESD safe table with a tabletop (mat) with 1M to earth you should also softground your solderiron so it has the same reference as the ESD safe environment.Floating would not be recommended. Hard ground could be done but don't forget it if soldering life circuits, the same as a hardgrounded scope probe on a life circuit.