Re: Intermittent nips when soldering

[alan alan]

As an aside, a lot of equipment uses electronic transformers and the "floating" outputs are at 'half line voltage' as if fed from a full wave bridge rectifier and capacitivly coupled across the transformer winding.  It fully meets to safety specifications but is a  noticeable nip by hand and an intolerable one on the lips.  Any unexpected light contact will cause a jump.
 
I now connect powered USB etc devices first and plug in the power lead second. I have caused a reboot of the PC connecting the other way round risking lost data and a failed USB card/device.  Despite that it is all supposedly fully compliant.
 
That is not, of course, to detract from Don's safety warning; we have 240V phase to neutral. 440V phase to phase is not available in domestic premises.
 
Regards  73  Alan
 

>Subject: Elecraft Digest, Vol 88, Issue 17
>________________________________
>From: Don Wilhelm <[hidden email]>
>To: David Dietrich <[hidden email]>
>Cc: "[hidden email]" <[hidden email]>
>Sent: Wednesday, August 10, 2011 2:30 PM
>Subject: Re: [Elecraft] (Slightly O/T) Intermittent nips when soldering
>
>David,
>
>I would take an AC voltmeter to that iron (right after you turn it on so it is not yet hot).? Measure between the iron tip and the AC safety ground wire (round hole in the receptacle).? If you measure *any* AC voltage at all, replace or repair that iron for your own safety's sake.
>
>If you are unsure of whether the AC receptacle's "green wire safety ground" is actually in-place and working, use one of the inexpensive electrical receptacle testers at the receptacle - if you do not have one, they are available at hardware and DIY stores.
>
>If the AC safety ground is not intact and you have your ESD mat and wrist strap connected to that ground, you may indeed have an ESD zap, particularly if your work area is carpeted or the humidity is reduced due to AC.
>
>IMHO, that is something that must be investigated immediately before it gets any worse and you end up with a good electrical shock - that could be fatal.
>
>73,
>Don W3FPR
>
>On 8/10/2011 3:15 PM, David Dietrich wrote:
>> Hi Dale,
>>
>> I find it hard to believe it is ESD because my soldering station is grounded and ESD safe.? I wear a strap whenever I need to.? I work in my ham shack that is my unfinished basement where the temp and humidity stay pretty constant year round.? I wear clothes made mostly of cotton.? My only guess is that a wire in the cord from the main unit to the pencil is shorting or something, however my soldering station has never been abused or mistreated in any way.? Also, one would hope that the actual wired in the cord are insulated from each other.? This has only started to happen over the last week or so.

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html