Current through the soldering iron tip
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Greg Smith
Larry Puckett had a item in the DCC Corner of the newest Model Railroader magazine about current being passed through the soldering iron tip which caused problems with some of his decoder installations. Is there an easy way to check this?
Greg ps - be kind - my electronics knowledge is limited:)
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Don Vollrath
With the soldering iron heating up measure for any AC or DC voltage from the iron tip to the grounding prong at a grounded outlet. If any voltage is detected there is a current leakage problem. Replace the iron.
DonV
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Put your AC Voltmeter between the tip and ground and see if you measure anything. It is really the voltage that could cause your decoders to blow.
You should check for DC voltage as well but this is less likely. Ken Harstine
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Denny Anspach
I am the person who alerted Larry to this issue, an issue notably prevalent in non-grounded irons, especially those with ceramic insulation. It becomes a potential lethal problem when soldering fine electronics (read: DCC decoders). An authoritative standard industry text book on electronic soldering strongly warns against using ungrounded irons on such circuitry.
This came to my attention when I sequentially fried the audio circuitry of three new sound decoders, and neither I nor the manufacturer had a clue as to what was happening (although -in frustration- not without some mutual polite finger pointing in the process). A model railroad EE engineer colleague (whose day job is industrial trouble shooting chip problems) -by elimination- discovered the problem: my faithful super-reliable non-grounded red Weller WLC100 soldering station was leaking a measured 28V through the hot iron (the cold iron had no leakage). I banished this iron, and a bunch of other ungrounded irons immediately from all electronic work, switched to a better grounded Weller station specifically qualified for electronic work ("ESD SAFE") and all problems disappeared like the snow in the midday sun. I have been installing decoders for almost 20 years, so this internal breakdown occurred somewhere along the way, or the decoder circuitry became more vulnerable. The WLC100 is a very popular work horse model, still very much on the market, and notably has not been sold by Weller as safe for electronics. Denny Denny S. Anspach MD Okoboji, IA
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Richard Gagnon
That came a a surprise to me as my station has the tree prong plug. Must be the internal wiring. I never did see any voltage issue though. Rich
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Greg Smith
Thank you for the heads up. I will test my Weller ( a 51 if memory
serves – or fails) tomorrow.
If it fails, I will continue to use for general soldering – ie working on
turnouts and general wiring, but will have to find a substitute for decoder
work.
Greg
From: Denny
Anspach
Sent: Tuesday, June 11, 2019 11:09 AM
To: w4dccqa@groups.io
Subject: Re: [w4dccqa] Current through the soldering iron
tip I
am the person who alerted Larry to this issue, an issue notably prevalent in
non-grounded irons, especially those with ceramic insulation. It
becomes a potential lethal problem when soldering fine electronics (read: DCC
decoders). An authoritative standard industry text book on electronic soldering
strongly warns against using ungrounded irons on such circuitry.
This came to my attention when I sequentially fried the audio circuitry of
three new sound decoders, and neither I nor the manufacturer had a clue as to
what was happening (although -in frustration- not without some mutual polite
finger pointing in the process). A model railroad EE engineer
colleague (whose day job is industrial trouble shooting chip problems) -by
elimination- discovered the problem: my faithful super-reliable
non-grounded red Weller WLC100 soldering station was leaking a measured
28V through the hot iron (the cold iron had no leakage). I banished this
iron, and a bunch of other ungrounded irons immediately from all electronic
work, switched to a better grounded Weller station specifically qualified
for electronic work ("ESD SAFE") and all problems disappeared like
the snow in the midday sun.
I have been installing decoders for almost 20 years, so this internal
breakdown occurred somewhere along the way, or the decoder circuitry became more
vulnerable.
The WLC100 is a very popular work horse model, still very much on the
market, and notably has not been sold by Weller as safe for
electronics.
Denny
Denny S. Anspach MD
Okoboji, IA
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Greg Smith
Denny
I checked and I have a WES 51. It is marked ESD Safe on the front of
the case. Do you know what “ESD Safe” means?
Greg
From: Denny
Anspach
Sent: Tuesday, June 11, 2019 11:09 AM
To: w4dccqa@groups.io
Subject: Re: [w4dccqa] Current through the soldering iron
tip I
am the person who alerted Larry to this issue, an issue notably prevalent in
non-grounded irons, especially those with ceramic insulation. It
becomes a potential lethal problem when soldering fine electronics (read: DCC
decoders). An authoritative standard industry text book on electronic soldering
strongly warns against using ungrounded irons on such circuitry.
This came to my attention when I sequentially fried the audio circuitry of
three new sound decoders, and neither I nor the manufacturer had a clue as to
what was happening (although -in frustration- not without some mutual polite
finger pointing in the process). A model railroad EE engineer
colleague (whose day job is industrial trouble shooting chip problems) -by
elimination- discovered the problem: my faithful super-reliable
non-grounded red Weller WLC100 soldering station was leaking a measured
28V through the hot iron (the cold iron had no leakage). I banished this
iron, and a bunch of other ungrounded irons immediately from all electronic
work, switched to a better grounded Weller station specifically qualified
for electronic work ("ESD SAFE") and all problems disappeared like
the snow in the midday sun.
I have been installing decoders for almost 20 years, so this internal
breakdown occurred somewhere along the way, or the decoder circuitry became more
vulnerable.
The WLC100 is a very popular work horse model, still very much on the
market, and notably has not been sold by Weller as safe for
electronics.
Denny
Denny S. Anspach MD
Okoboji, IA
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Electrostatic discharge... Craig Zeni Cary, NC Despatched from my infernal Android
On Tue, Jun 11, 2019, 21:11 Greg Smith <gcscls@...> wrote:
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Dennis Cherry
No matter how good your soldering is and has all the safety features needed, if you use a 3 prong to 2 prong adapter then it is no better than a cheap soldering iron.
The Safety ground has a purpose, your house wiring has to have the 3rd wire (Ground) also and have a copper stake in the ground connected to the third wire. The White wire is called neutral and is only used as the return wire for 110/120 VAC not a safety ground. Dennis
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JBJudy
This comment causes me to ask for a clarification ............
"Thank you for the heads up. I will test my Weller ( a 51 if memory serves – or fails) tomorrow. If it fails, I will continue to use for general soldering – ie working on turnouts and general wiring, but will have to find a substitute for decoder work. Greg" Very interesting topic. Sounds like the issue is only when soldering the decoders. Is the "leaking voltage" not harming an engine on the track when soldering feeders? JB Morrow
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Charles Brumbelow
An older house, originally wired with two rather than two plus ground, may have some/all outlets with three prongs where inside the box the ground terminal is connected to the white (neutral) wire. And the three to two adapter which fastens to the screw holding the cover on is worse than useless unless metal conduit was used throughout the building.
toggle quoted messageShow quoted text
On Wednesday, June 12, 2019, 7:27 AM, Dennis Cherry <dbcherry@...> wrote:
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Denny Anspach
ESD SAFE reportedly is the sign that the iron is grounded and labeled to be safe for CMOS and similar electronic work. My current Weller is so labeled, and apparently it is the same iron also commonly used in the nearby gigantic Intel plant (California location).
Denny Denny S. Anspach MD Okoboji, IA
Denny S. Anspach MD
Sacramento CA
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Greg Smith
Thank you for the info. Still, I will test it the next time I fire it
up. Has generated some conversation on the forum. My shop, wired by
myself, does have a separate ground wire and all receptacles are new three prong
plugs. So that should not be an issue.
From: Denny
Anspach
Sent: Wednesday, June 12, 2019 3:31 PM
To: w4dccqa@groups.io
Subject: Re: [w4dccqa] Current through the soldering iron
tip ESD
SAFE reportedly is the sign that the iron is grounded and labeled to be safe
for CMOS and similar electronic work. My current Weller is so labeled, and
apparently it is the same iron also commonly used in the nearby gigantic
Intel plant (California location).
Denny
Denny S. Anspach MD
Okoboji, IA Denny S. Anspach MD
Sacramento CA
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As from a previous thread...(deleted by management)
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Max Maginness
I did a census of soldering irons on hand
All were two wire except the WES D51 In no case was the leakage current to ground more than 20 microamps. There is no personal shock hazard but you might not want to touch a hot tip for other reasons anyway.
Max
From: w4dccqa@groups.io <w4dccqa@groups.io> On Behalf Of Greg Smith
Sent: Wednesday, June 12, 2019 1:18 PM To: w4dccqa@groups.io Subject: Re: [w4dccqa] Current through the soldering iron tip
Thank you for the info. Still, I will test it the next time I fire it up. Has generated some conversation on the forum. My shop, wired by myself, does have a separate ground wire and all receptacles are new three prong plugs. So that should not be an issue.
From: Denny Anspach Sent: Wednesday, June 12, 2019 3:31 PM Subject: Re: [w4dccqa] Current through the soldering iron tip
ESD SAFE reportedly is the sign that the iron is grounded and labeled to be safe for CMOS and similar electronic work. My current Weller is so labeled, and apparently it is the same iron also commonly used in the nearby gigantic Intel plant (California location).
Denny
Denny S. Anspach MD Okoboji, IA
Denny S. Anspach MD
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When soldering feeders on you layout and large circuit boards there is enough leakage to ground to take care of the problem. Also the track connections of the decoder is the least susceptible to this problem because of the power capacitor that is on the board. The smaller the decoder the greater the risk.
Best Regards, Ken Harstine
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JBJudy
I am looking for clarification as I have this Weller unit & it is NOT MARKED ESD SAFE!
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On Jun 13, 2019, at 9:33 AM, JBJudy wrote:
I am looking for clarification as I have this Weller unit & it is NOT MARKED ESD SAFE!Then don't do decoder or electronic work with it. I wouldn't risk smoking a decoder with a non-ESD safe iron. Craig Zeni Cary NC
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Don Vollrath
ESD Safe is not the exactly the same as current leakage or as simply grounding the tip of a soldering iron. There is as special spec and requirements for it to protect sensitive electronic equipment.... like microprocessors and amplifiers used inside decoders. Remember seeing sparks from your fingers when handling wool sweaters in dry humidity conditions? See https://en.wikipedia.org/wiki/Electrostatic_discharge.
BTW - When you use a grounded soldering iron make sure that whatever thing you are soldering to is NOT energized. Otherwise you are creating a direct path for current to flow from whatever source it is connected to by touching it with a grounded soldering iron. DonV
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Michael Rozeboom
On 2019-06-13 9:33 a.m., JBJudy wrote:
I am looking for clarification as I have this Weller unit & it is NOT MARKED ESD SAFE!
Then it is not. ESD safe units are identified with the ESD safe
symbols. Older units have the three prong plug, and they are not
ESD safe.
--
Michael Rozeboom
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