Decentralising a narrowboats electrical system

[GSer]

Just thinking about the fit out of my next boat and was just pondering over the electrical system.

 

The new boat is 70ft long, the Galley will be at the front of the cabin, in my present boat I have had some issues in the past with the volts drop to the fridge this was cured by heavier cables and being a bit sneaky with battery location.

 

Initially i was thinking of using a can bus system in the boat but that is getting a little pricey for any advantages gained.

 

So i was wondering if I could

 

1, At the stern, run a bank of batteries, combo inverter, generator, dc-dc transformer ?(i want to fit led lighting and I think this gives a stable 12vDC) Then at the front for the Galley either run 240v up to the galley to a 240AC/12vDC transformer to run the 12v galley and fore end 12v equipment

 

or 2, same as above but at the front have a separate battery bank, charged by a 240/12v charger

 

or 3, run the boat at 24v (can you get led's at 24v?) this would also mean changing the starter and alternator to 24v.

 

Or am I worrying to much and I should just get on with it

 

Paul

[nb Innisfree]

We fitted a couple of bowthruster batts at the front and a 230v/12 charger run from a Victron and while BW was working batts charged up nicely. I think batts+charger at the front would be more efficient than a 230v/12v transformer given that they are not very efficient at differing loads? at least a 3 stage charger would be more efficient even taking into account inverter losses. Just switch charger on when running engine though if front batts are down and rear ones up you could do some charging with engine off, an extra facility as it were. Surely the inefficiencies of a DC to DC transformer outweighs the advantages of low power LEDs especially if you tend to run just a few at a time?

 

Stand to be corrected

[Chris Pink]

My recommendation would be to run fat (10-16mm²) 12V cables up to the galley then either have a fuse box there or run fused spurs to equipment.

 

A 12V bus running the whole length of the boat with say 4 take off points gives you one of the main advantages of canbus without the expense or reliability worries.

[sentinel]

Just thinking about the fit out of my next boat and was just pondering over the electrical system.

 

The new boat is 70ft long, the Galley will be at the front of the cabin, in my present boat I have had some issues in the past with the volts drop to the fridge this was cured by heavier cables and being a bit sneaky with battery location.

 

Initially i was thinking of using a can bus system in the boat but that is getting a little pricey for any advantages gained.

 

So i was wondering if I could

 

1, At the stern, run a bank of batteries, combo inverter, generator, dc-dc transformer ?(i want to fit led lighting and I think this gives a stable 12vDC) Then at the front for the Galley either run 240v up to the galley to a 240AC/12vDC transformer to run the 12v galley and fore end 12v equipment

 

or 2, same as above but at the front have a separate battery bank, charged by a 240/12v charger

 

or 3, run the boat at 24v (can you get led's at 24v?) this would also mean changing the starter and alternator to 24v.

 

Or am I worrying to much and I should just get on with it

 

Paul

 

Paul;

 

I dont feel that there is a need to run any form of LED lighting off a DC-DC converter as the light output (to the human eye) of an LED or LED cluster is fairly constant over the likely range of supply voltage (and hence current throught the LED's) that you are likely to encounter. Whilst switch-mode DC-DC converters are fairly efficient these days such a scheme just adds complexity, cost and does introduce losses. Well thats my thoughts anyway!

 

Actually incandescent lighting would have been another matter given the dramatic effect voltage has on lamp life, but this is generally ignored on a cost/benefit basis and the fact that "x" hours at over-voltage is sort of offset by "y" hours undervoltage - maybe.

 

Regards

 

Ian

[GSer]

Paul;

 

I dont feel that there is a need to run any form of LED lighting off a DC-DC converter as the light output (to the human eye) of an LED or LED cluster is fairly constant over the likely range of supply voltage (and hence current throught the LED's) that you are likely to encounter. Whilst switch-mode DC-DC converters are fairly efficient these days such a scheme just adds complexity, cost and does introduce losses. Well thats my thoughts anyway!

 

Actually incandescent lighting would have been another matter given the dramatic effect voltage has on lamp life, but this is generally ignored on a cost/benefit basis and the fact that "x" hours at over-voltage is sort of offset by "y" hours undervoltage - maybe.

 

Regards

 

Ian

 

 

Thats interesting, I thought LED lighting was very voltage sensitive unless it had the built in transformers(?) to cope with 'Auto' use.

 

Still, lots of interesting ideas to consider

[GUMPY]

Although my barge is 24v I have done a similar thing and have a fuse board in the kitchen.

However its fed with 25mm cable...............If I was doing similar for 12v I would use 35mm cable as a minimum.

 

IMO 10-16mm is not anywhere near heavy enough, I use 10mm just for the fridge and that only 5ft from the board.

 

If you are really concerned that there will be to much volt drop just run a 240v fridge on an inverter that's what I do with the main fridge/freezer there is no point going 12>240>12 at all

 

My 24v fridge is just for beer no food allowed in that

[Amicus]

If yer gonna run a 230v fridge off an inverter there's an intresting gizmo here

 

http://mtbest.net/chest_fridge_1.pdf

shuts everything down when the compressor is not running, allows the inverter to go to sleep

[steelaway]

Just thinking about the fit out of my next boat and was just pondering over the electrical system.

 

The new boat is 70ft long, the Galley will be at the front of the cabin, in my present boat I have had some issues in the past with the volts drop to the fridge this was cured by heavier cables and being a bit sneaky with battery location.

 

Initially i was thinking of using a can bus system in the boat but that is getting a little pricey for any advantages gained.

 

So i was wondering if I could

 

1, At the stern, run a bank of batteries, combo inverter, generator, dc-dc transformer ?(i want to fit led lighting and I think this gives a stable 12vDC) Then at the front for the Galley either run 240v up to the galley to a 240AC/12vDC transformer to run the 12v galley and fore end 12v equipment

 

or 2, same as above but at the front have a separate battery bank, charged by a 240/12v charger

 

or 3, run the boat at 24v (can you get led's at 24v?) this would also mean changing the starter and alternator to 24v.

 

Or am I worrying to much and I should just get on with it

 

Paul

 

 

Hi Paul

 

Why not just have a 240v fridge there isn't that much saving in efficiency and a definet saving on the purchase price.( and choice)

 

Alex