[aprssig] slightly OT:recessed male twist and lock

Andre PE1RDW aprs at pe1rdw.demon.nl
Sun Feb 5 17:19:28 EST 2006

Dale Blanchard schreef:

> Joe Della Barba wrote:
>>  >>>
>> Or to put it another way a 240V center tapped system like the stupid 
>> USA uses.
>>  >>>
>> Why is this stupid? Is there a better idea? I have always wondered 
>> about the European 220v system. Is one side grounded or is it floating?
>> 73
>> Joe
> __________________________
> Floating.
> You do not get shocked unless you touch both wires.
> US way was a cheap way to get two circuits from only three wires.
> I have worked in areas were the grounds were lifted do to problems
> with weird current paths..

To be acurate, European system has 3 phases, a zero or return wire and a 
earth wire.
In a typical house instalation only one phase is used (the used phase 
alternates every house) this gives a 230 v ac potential to the zero 
wire, a very fast safety breaker is installed in the fuse box that will 
trip if there is a current difference between the phase  and the zero, 
the earth wire is only used as a safety to ground the metal case of 
apliences and normaly would not cary any current, if it does then the 
current between phase and zero is not equal and the safety switch will trip.

In case more power is needed then can be applied with just one phase all 
three phases can be used to power 3phase 380v motors and heaters, it´s 
called 380v because the potential difference between two phases is 380 
volts, this system does not use the zero wire.

There are 4 types of plugs in use, unearthed plugs for living room etc, 
earthed plugs for kitchen and laundry room etc, blue weather sealed plug 
with 3 pins for outside use and red weather sealed plug with 4 pins for 
the 3 phase 380 v systems.

At least that is the system used on mainland europe, there might be some 
detailed variation in the UK system but the basics are the same.

73 de Andre PE1RDW

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