Electrics

For starters, like a lot of narrowboats these days we would like the convenience of 240V whilst maintaining the use of 12V where practical. For those of you who have no idea about electricity, a couple of useful facts

  1. You can't get a shock off 12V (Well not unless you connect the electrodes to particular moist tissues - like ... your tongue!) Therefore it is difficult to kill yourself with 12V - This is a good thing
  2. You can get one doozy of a shock of 240V - it can really spoil your day if not end your life - so please take care!

As we are not contemplating living aboard we shall restrict ourselves to inverter driven 240V and the use of a landline at the marina. Many private moorings have 240V available to plug into (for a price of course!) - excellent to keep the batteries topped up and for working on the boat.

12V

As stated 12V is great because its nice and safe - so why don't we use it everywhere? - well in a nutshell we would need great big thick wires to carry the current. Time for lesson 1.

For those of you who can't wait - here's the wiring schematic for The Cat's Whiskers

240V

Those of you who have perused the wiring schematic might have noticed that it's a bit odd in that we have two inverters supplying 240V. Well its not as mad as it seems (well I don't think so!) The one inverter is a 600W inverter/charger by Sterling which is specifically designed to run 240V fridges - its big advantages are it very high surge capability (needed to handle the high surge currents required to start a fridge) and a very low quiescent current (the amount of current used by the inverter whether the fridge is on or off - without this the system would be very inefficient when the fridge thermostat switched it off). This inverter is capable of running the fridge and a small accessory as well. When you consider the cost of a 12V fridge compared to a 240V one, you can save the £200 cost of the inverter and have a much larger choice of fridges.

But why the second inverter? - well we want a microwave - why? - because we like scrambled eggs but hate cleaning the saucepan! Now we only need this inverter part of the day (unlike the fridge) so we are not so worried about the quiescent current - a 1200W inverter will run the microwave, tv, video, small hairdryer etc at a reasonable cost.

So why don't we have one big inverter - well apart from the quiescent current savings on the fridge - its actually cheaper to buy two smaller ones and if one breaks, its cheaper to replace/fix. Also I now have a system exhibiting 'redundancy' - I don't need both - I can have 240V for essentials (ie fridge), if the one breaks I can reconfigure the wiring to run everything off the other(you just have to be careful what you switch on together!!)

So there you have it The Cat's Whiskers electrics - I will write more on landlines etc. later