Topics

Current through the soldering iron tip

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:)

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

 

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

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



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

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
 
 
 

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
 
 
 

Craig Zeni
 

Electrostatic discharge...

Craig Zeni
Cary, NC
Despatched from my infernal Android

On Tue, Jun 11, 2019, 21:11 Greg Smith <gcscls@...> wrote:
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
 
 
 

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

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

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. 

Charles 




On Wednesday, June 12, 2019, 7:27 AM, Dennis Cherry <dbcherry@...> wrote:

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

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 




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



 

Mark Cartwright
 

As from a previous thread...(deleted by management)
>>> I am a big proponent of a properly wired AND Grounded (with pound in ground 10' spikes) 
BEFORE 
Beginning any phase of DCC ...
be it wiring the layout.
plugging in the DCC controller..
And YES...
Using a Three Prong Ground Receptacle which has Not just been hung on the wall for looks
> Even for soldering.
====
In this old house...I found many an outlet which was out of phase (and out of gauge).
:)) Mark

OT...
I just spent more than three grueling days running a new line out to the AC Compressor in 100+ heat.
The wire to that location ?
I don't know....I had cut it previously as I began to simply rip out what I saw as a potential fire hazard.
Since my last posting however...I found a hidden Circuit Breaker Box hidden behind a built in cabinet...only accessible by removing a drawer.
Whose to know?
The wires leading to it...were under gauged and aluminum.  Didn't bother to figure out what it went to...
I removed it immediately.
Oops! It may have connected to the AC Compressor.
I only became seriously motivated when the heat was about to top 99 degrees.
All now successfully replaced. I got AC Again !

Max Maginness
 

I did a census of soldering irons on hand

 

Type     

Tip voltage relative to ground

WLC 100 

26 volts

Weller WES D51  ESD

<0.1 volts   (3 wire)     

Archer (Radio Shack )

3 volts

Ungar (about 40 watts)  

6 volts

Weller (35 watts)

40 volts

 

 

 

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
Sacramento CA


 

 

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

JBJudy
 

I am looking for clarification as I have this Weller unit & it is NOT MARKED ESD SAFE!

Craig Zeni
 

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

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 
  

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