A shocking discovery?

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I can sense a very mild "tickle" effect when I touch the telescope or mounting with my fingertips. Best described as if the metal is slightly "sticky" to the touch. At first I thought it was low level vibration but I'm getting a very slight, neon, orange glow on the electrical test screwdriver. The screwdriver has to be very well shielded from the light, or dark in the dome, to register any glow at all.

It is not normal for the 2-pin mains sockets to be earthed here in Denmark, except in brand new installation work where 3-pin sockets are presumably fitted. We had some new sockets fitted and they used all 2-pin to match the rest of the house. The Danish mains plugs are obviously 2-pin too. So reversing them in the socket, each time something is plugged in, is completely normal behaviour here.

Most mains appliances bought here have a 2-pin, moulded-on plug from new. Hi-fi components, TVs, kettles. toasters, lamps, lawnmowers, hair driers, power tools, etc. are all 2-pin, mains devices. The consumer unit has a sensing device to protect the occupants. While a 10A fuse in the consumer unit protects devices from the consumers.

My observatory is fed by a 30 meter, 2-core extension lead. My home made mounting only ever sees the 12V, two core, 2 pin plug, power supply for the AWR stepper motor drives. Which are intimately connected metal-to-metal to the mounting.

Green earth leads are provided on the various AWR motor connecting cables but I have never bothered to connect them. [Yet.] I always presumed these were only for use in UK, earthed, 3-pin systems. Which are usually protected by a dedicated RCD socket adapter for outdoor use. As is recommended for lawn mowers and other mains power tools in the UK.

There never seemed any point in earthing my 12V connecting cables unless I actually provided a local earth spike. Which would then have to be connected to the mounting with a hefty [lightning?] conductor.

The mounting is presently well isolated, by the well protected, dry timber construction for the 14 odd feet pier supporting it. The feet of the pier are bolted to pre-cast, concrete foundations blocks but these are within the dry building area. Above the mounting is the insulating plywood dome.

Should I give the mounting a direct route to ground? That might raise the potential for shorting to 250V for any other mains driven service in the observatory. Things like my LED light bulbs run on mains. Do I increase the risk of a lethal shock if I am touching the [newly] earthed metalwork? I really have no idea.

Perhaps I should simply reverse the 2-pin mains plug in the 12V power supply? We soon discovered, on arrival in Denmark, that our imported [UK] home appliances lost their shock potential when we did that. The "British" metal sewing machine was a case in point. A tickle of electricity when touched was confirmed by a bright glow from the test screwdriver! We reversed the 2-pin plug and there were no more shocks and no more neon glow.

Danish bought washing machines can give a shock when the 2-pin plug is put in the "wrong way" around. No shock the other way. So I routinely mark the plugs green and red. Now they always go in orientated correctly without any problem. There is the German Schugo system of earthing but I'm not sure it offers any protection unless used with 3-pin plugs and sockets.

What I could do is run a hefty 3-core extension lead out to the observatory and use 3-pin sockets instead of 2-pin. Perhaps what I really need is a "tame," Danish electrician to advise me. Without getting into a full mains system with consumer unit and multiple outlets in the observatory.

Readers in the US may wonder at the amateur way I am dealing with the electricity supply. They have countless rules governing all aspects of building. If I really was breaking all the Danish installation rules then I'd simply revert to a rechargeable battery. To provide a 12V DC supply for the drives and matching LED lights.

Saturday: Cloud again. Lots of high cloud making the sky milky and the sunlight soft. Checked the effect of plug reversal. Zero effect. Identical, dull, neon glow from both plug orientations. My camera wouldn't register the neon glow so you'll just have to imagine it.

I bought some more of the nested, snap-on lid, plastic storage box/tub sets. I needed more of the small ones rather than the larger. Now I could separate accessories between regular and occasional. No point in repeatedly handling items which are only rarely needed. Nor unnecessarily exposing them to dust and dew. Small boxes leave less room for confusion since it reduces choice in the dark. A red light over the top shelf would be useful but I don't want anything projecting just there. The height of the tops shelf was chosen to allow clearance for the boxes.

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