Quote:
Originally Posted by ben
All my series 15 units came with 3-core leads. I have a series 12, of roughly similar vintage, bought in Europe which has a 2-core mains lead and moulded plug. So it clearly depends on country of origin.
In Europe you can still find unearthed schuko-style mains sockets in vast numbers of properties. In our place the schukos are unearthed apart from in the kitchen.
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I think it varies both depending on country and time frame. I've had a few series 15's over the years, all manufactured for and sold for the Swedish market, and the mains leads were 2-core up to some point, after which they went to 3-core, but even on the 2-core machines there is an obvious earth terminal intended for a 3-core connection.
Earthing in Europe varies between countries. In Germany, eathing is mandatory, in fact, it is not legal to operate unearthed equipment that is not double insulated (i.e. has an unearthed schuko, it is safe and legal to operate double insulated equipment which has a 'flat' two-pin Euro connector). In Sweden where I live, up to some point, I think in the late 1990's or so, earthing was only mandatory in kitchens, bathrooms, and other locations exposed to water. Some premises have an additional room with earthed outlets, intended for operating computers and other equipment where one is expected be in contact with them for long periods of time. Today I think earthing is mandatory in all newly built premises in this country.
Regarding earthing and exposed metalwork, as I understand it, the safety of such equipment is partly based on the fact that it is operated in a room in which there is no exposed grounding points, ergo, you can't get an electric shock from touching said equipment because there is no exposed ground for the current to flow to. Radiators are grounded, but also covered in paint, i.e. isolated (yes, I know that is debatable). The question of an electrical fault in two pieces of equipment is another issue, I think it is considered a 'double fault', i.e. much more unlikely than a 'single fault'.
The dubious nature of this 'isolated room' concept is one of the reasons earthing is becoming mandatory in more and more countries.
Finally, I'm not sure this point was clear to everyone in this thread, ground loops are not a problem when operating equipment in isolation, but when connecting together several pieces of equipment, i.e. a sound system with audio interconnects between the components, an electrical loop will be formed between the ground wire of the audio and the earth wire in the mains wiring. The loop will be susceptible to the mains magnetic field, and will induce hum into the audio channels of said equipment due to the small but sufficient potential difference that is created due to the current flowing in the loop. Often, this effect ground loops can be minimized by relocating cables so that the area of the loop is minimized.