Hi all,

While I was operating my trains today, I noticed a small tingling feeling when touching the track rails.
You know, the little feeling which you get if you place a 12v battery on your tongue.
I have never noticed this before, but today I was standing barefoot on the ground.
I wondered whether there was an earth leakage somewhere.

So, I hauled out my Multimeter, and measured the electrical potential difference between rail tracks and myself standing barefoot on the ground.
I was touching the Red needle to the Multimeter, while the Black needle was touching the rail.
Sure enough, there was about 8v AC current conducting through my body to the ground.
(Note that the locomotive lights are ON in the following picture)


I then went to switch my Central Station 2 onto the "Stop" position.
And I measured the electrical potential difference again.
This time it registered about 2v AC current conducting through my body to the ground.
(Note that the locomotive lights are OFF in the following picture)


This obviously puzzles me.
Maybe one of the electrical engineers on the forum can explain what is happening.
All the locomotives and all the s88 and all of the accessories were working perfectly.

Regards
John

I have always felt the tingle from my track and due to the low voltage have never worried about it. To avoid this I usually just push the Stop bar on the CS2 whenever I am doing any work on my layout that requires my arms or hands to be on top of the track. The tingle gets very annoying.

In my opinion the power supply to the CS2 does not transfer the household ground to the CS2 and the CS2 then supplies the B and O to the track with the O at a floating potential compared to actual ground. Therefore, the potential difference you are measuring.

Peter

Hi John,

Yes see previous post and results.

To get more accurate result try and measure ground potential between your rail and e.g. a radiator pipe or water copper pipe that has solid connection with earth (instead of your finger).

Then after this testing try and rotate your main plug for the power pack (if you have a eu plug you simple rotate the plug).

My test results were around 170V and then dropping to 60V (which Iam unable to feel when touching the rails). Even though voltage seems high there is hardly any amperage or flow or current.

My research into this matter indicated it’s a known issue with switch mode powerpacks and unless you get a power supply with earth pin fitted you will have this type of ground leakages.

I did inform Marklin about my result and they did testing, but would not acknowledge any faults or design issues, all though I did see some time ago a technical advise (in German) posted by one forum member here that seems to acknowledge the issue.

Best Regards
Lasse

Hello Peter,

On some occasions I have noticed this also, but felt it no big deal. My impression was that my body provided a conduit between the centre studs and the outer rails (rather than a conduit to "ground")

I noted from the Märklin stuff that there is a constant voltage across the track (centre stud to outer rail, that is). I understand that it is not classic constant DC nor classic AC sine wave but rather a complex composite of various square wave modulations (from the digital signal) of DC and as such is not amenable to accurate measurement by the standard multimeter as "AC" nor "DC", but it is + to - about 20 -22 v. I suspect my sensation of it varies with the climate conditions and my own conductivity(?)

Now, this was no problem for me but one day the layout assistant (image below) whilst pursuing his duties (an alternative "track-cleaner" as has had much recent discussion on this forum) happened to place his Cocker Spaniel snout on the live track (usually this is "happy moist" and thus has a thin layer of saline-rich, highly conductive, mucus) . There was a quick yelp and rapid withdrawal !!

Have fun,

PJ



(checkout the happy moist nose ! )