23 Nov
2014
23 Nov
'14
3:12 p.m.
But if you'd ask any utilities manager why not
move to 3-phase
residential distribution, you'd get the response that residential
distribution was, in fact, 3 phase--one phase per household.
Over here that is often the case. The distribution cable is 3 phase and
different houses along the road get one of the phases brought in. For
some reason (read : because they can get away with it), having all 3
phases brought into one house is difficult to get and expensive.
To answer Tony's question about power tools,
almost all hand/portable
power tools are rated for 15A or less. My router (Bosch, if it
matters), claims a rating of 3 hp and maximum current of 15A at 120V.
Over here, a motor rating in W refers to the electical input power, one in hp
to the mechanical output power. At least from reputable companies.
Yes, I know that 3 hp is about 2200W and therefore
almost 19A at 120V.
Such is the nonsense that goes for nameplate ratings in the US. Vacuum
cleaners are rated at the motor's "locked rotor" current draw, as
another example.
I guess the ratings of audio power amplifiers is another. I am still wondering
why the world has an energy problem given I can get a 360W PC speaker system
that runs off a 12V 1A PSU.
Wasn't the UK slow to standardize on receptacles
and plugs? I seem to
Strictly it still hasn't. While you are very likely to find the BS1363 13A socket
outlet just about everywhere, the BS546 round pin sockets are still allowed
even on new wiring (AFAIK, they certainly were a few years ago). And there
are other permitted sockets too.
recall a mention that some appliances long ago were
supplied without
plugs altogether; the customer was supposed to install whatever was
suitable.
Yes. Now it is a legal requirement that portable equiment is supplied with a
fitted BS1363 plug. I am sure there are exceptions, e.g. for 110V power tools,
etc. In many ways I wish things still came with no plug. It would mean I wouldn't
have to cut off the possibly dangerous moulded plug first...
In the 1950s/1960s all sorts of plugs were common over here. Repair workshops for
radios, etc, often had an array of different mains sockets at each bench. Of course there
were also 'suicide leads' (mains plug to croc clips) which you hid from the safety
inspector.
Field service engineers (for domestic TVs, kichen appliances, etc) would have a problem
plugging in their soldering iron, etc. There were a variety of universal plugs made, some
safer than others.
I bought a second-hand slide projector over here and it came with about 10 mains leads
ending in assorted main plugs 2 and 3 pin, even a bayonet lampholder plug. The old owner
had
used it for illustrating his lectures and he never knew what socket he would find in the
lecture hall...
-tony
--Chuck