ASR-33 conversion to 220V

Chuck Guzis cclist at
Thu Dec 7 19:39:50 CST 2006

On 8 Dec 2006 at 0:32, Tony Duell wrote:

> AFAIK no equipment, either US or European can assume that one side of the 
> mains is grounds (and safe to touch). 

I own a Toshiba microwave oven (with 3-prong grounding plug) that 
will not power up if the mains socket is wired up with the feed 
reversed.  Drove me crazy the first time I tried to use it until I 
discovered that the idiot who wired the kitchen receptacles swapped 
black and white at one socket in the string.  The same refusal to 
work may be true of some ground-fault interrupter receptacles (i.e., 
they always stay "tripped" if wired backwards).

The local Cheap Chinese tool place regularly has a special on 
receptacle testers that make sure that the wide blade in the 
receptacle is at ground potential.

> [For those who wonder what on earth I am talking about, portable 
> industrial power tools -- electric drills, for example -- in the UK are 
> 110V devices. 

At what level does this not hold true?  For example, I've got a nice 
big router (portable) that draws a full 15 amps at 120v at startup.  
That would be a pretty large transformer.

Nowadays, however, most portable tools are simply constructed as 
"double insulated".


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