Well holiday time finally came
around! I woke up one morning and my Commanding Officer was doing a final kit
inspection of our suitcases and making sure that there was no way any air from
Oxford was getting in those cases. We usually take so much that I manage to
hurt my back lifting cases to go on holiday. Anyway this time we were able to
split the load a little by going on a cruise where they let us take two
suitcases each. So we loaded up the old four-wheeled chariot and set off for
Southampton and our appointment with the Queen Mary II. We had the Sat-Nag on to get us to
the docks but my god, it’s a wonder we couldn’t see the ship from Oxford – it
is massive. Without going into loads of figures, from the keel to the top of
the funnel is higher that Big Ben (I didn’t actually measure it to check). And
you don’t have a cabin, you have a “Stateroom” – don’t you just love it
already. To show how my mind works though, I
was pleased to see 13 Amp outlets throughout the ship as well as that
namby-pamby 110v stuff. Now, with regard to US/UK voltages I have a theory –
would you like to hear it? Of course you would! First off though, Tesla was the
father of AC, Edison was promoting a DC system which was only any use for small
scale transmission. Tesla realised that for long-haul transmission and
distribution Alternating Current was the only way to go (although recent
breakthroughs may make DC transmission attractive in the near future). There
are many books and papers on Tesla and without doubt the man was a bloody genius
and there are many things he worked on that remain a mystery to us today.
However, my theory is that when the Americans were trying to decide on what to
set as their working voltage level they jumped too soon. Now we know that 50
volts is the line that we draw in the sand for safe working, in other words
above 50V is dangerous. But on the other hand we know that Power (Watts) has an
inverse relationship with Voltage and Current. So if we lower the voltage
current is increased, so we reach a point where we have to decide a reasonable
supply voltage at a reasonable current (to keep wire size down) to deliver a
reasonable amount of work done (Power, in Watts). I would have loved to have been a fly
on the wall in the design office at Tesla/Westinghouse at this time and intend
to do some more research on this, but it must have gone along the lines of
“Well Boss, 100V single phase voltage would be peachy, but with losses takes
the current to above 10Amps for a 1kW load, If we increase that to just 110V
per phase we get the line current down to 9.3 Amps” says guy with
bottle-bottomed glasses, braces and a voice like Kermit the frog as the rays of
a NY sunset shine through the smoke-filled room (come on, where’s your sense of
theatre).”That means we can use a 12 AWG instead of a 11AWG size cable for a
1kW circuit boss” he continued. “Okay” says big fat, cigar chewing
boss “Let’s do it”. And so 110V single phase distribution was born in the US
(At least that’s the Ted Barrett *temporary version). And now back to my comment on
“jumping too soon”. Although most US domestic installations are 110V, what most
of us Brits don’t realise (and probably most US non-sparks) is that US premises
have another phase brought in. So they have 110V for lighting, TV and most small
appliances but cookers and washing machines are wired phase to phase which
gives them a pressure of around 190 Volts. This in turn reminds us of the
problems with a lower voltage single phase voltage and makes me think that the
110V delivery system was born purely to serve lighting and the phase to phase
solution brought in as advances were made in electrical appliance technology. I
believe though, the bottom line is that we in the UK benefitted from the US
experience and set our single phase voltage higher to avoid bi-phase
distribution. Although, it is not impossible that Tesla and the guys only ever
envisaged a multi-phase distribution system anyway. As time allows, I will try
to follow up on this subject or if any reader can enlighten me I would be very grateful. Another thing I must say about a
cruise is that you want for nothing. It is very relaxing and you can just spend
your time resting eating and drinking. If on the other hand you have a guilty
conscience you can spend your time power-walking around deck, attending
lectures and eating salad. For my part, I think enjoyment lays somewhere
between the two camps. Anyway, we were somewhere off the
coast of Newfoundland when my CO informed me that her hair-straighteners
weren’t working. Now, to those of you that think this is just a trifle, you are
very much mistaken. This at least made me open one eye and engage the major
part of my cerebral cortex in a repair plan. A quick examination confirmed
suspicion number #1 – continual flexing of cable causing cable damage at plug
end. If I were a super hero “Repairman”, I could have welded the damaged
strands inside the flex with my heat-vision. Sadly, I didn’t even have a pair
of cutters. In the course of my married life I
have got used to taking a First-Aid kit and various potions in order to repair
my wife as she frequently breaks down or malfunctions while away. To the same
extent I usually pack a few screwdrivers etc to repair the things she breaks
“It came off in my hand”. However, as we were on a transatlantic trip and I
knew customs to be very tight, and we were being pampered by Cunard, I didn’t
think I would need to pack a toolbox. So, back to the straighteners. On
closer examination the cord was actually terminated in a 2-pin plug that
snapped into a receptacle ending in a 13A plug. So the conundrum was: No tools
and no 13A plug to re-terminate in. Nonetheless, using a nail file, manicure
scissors and a Band-Aid, I managed to effect a repair that returned the item to
working order thus earning a mention in despatches from my CO. It must though
be said that my repair was definitely against the requirements of BS7671, EAWR,
NEC (US Regs) and I would certainly imagine Marine Engineering Instructions.
However, I can say that the equipment was only operated under my supervision
and a full repair was made on return to base. I should also imagine that while
I was doing this, a handful of poor sods in yellow galoshes and whatever were
being thrown from one end to the other of a small fishing trawler in minus 100
degree temperatures with their eyebrows and ears snapping off in the cold. Or
do I have too much of a vivid imagination? But back home and back to reality, a
mountain of post, the next round of home maintenance and courses to schedule
in. I’m thinking of developing a “Domestic Installer” course with my good chum
Ian Griffiths to run at OEA in 2017 so will start to flesh this out very soon.
I know that a lot of electrical contractors don’t approve of this but let’s be
honest, if we don’t do it somebody else will. And I would rather be doing the
training and assessment to ensure only candidates who are competent and SAFE
get through the process. I also think that this course could
fill the gap that is no longer offered by local colleges of providing a way into the
electrical trade as it could be offered as evidence in application for
employment. As a training professional and an industry insider, I firmly
believe that a major re-hash is needed in the field of electrical
installation work. I think we need to restructure the grading system as we have
too high a technical content required for those who simply want to be
electrical installers. For those that think otherwise, you want to try teaching
power factor to apprentices that only want to (and only ever will) install
conduit and trunking. I will explore this further in future and list my
proposals in more detail. *With regard to the detail of
the “Jumping too soon” story, I can see I need to do some serious research. I
had thought to build a time-machine and travel back in time to find out more,
but you know how it is with this time travel stuff. I’d probably bump into
myself coming back and then have to go back again and stop myself going back
again or drop a bus-ticket and cause a huge timequake through the space-time
wotsit. So I’ll just have to find out the old-fashioned way. |
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