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Newby questions about eleccy


Jason Pay
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Good Day!

Hopefully a liveaboard by the summer, I have a question regarding eleccy on board.

 

The boat I'm hopefully buying, I will be firstly living on the hard for a year while I ponder and fit out to my requirements and then onto a permanent mooring.

So eleccy will always be available, am I right in thinking I can run the shore power lead to a trip box and then from the trip box, wire the boat as you would a house with 240v sockets in and around the place.

If say for holidays and weekends I want to go wondering on the river these would need to be fed by a 12v battery bank and suitable inverter?

Correct me if I'm wrong so far...

My question is... how many plugs can shore power supply? How much output can I expect to be handled in a boat or is it limitless? Say of an evening I had me and my girlfriend had our laptops charging, a tv running and some mains lights. Then the kettle every half hour for a healthy distraction from university...

 

Thanks Jason

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Good Day!

 

Hopefully a liveaboard by the summer, I have a question regarding eleccy on board.

 

The boat I'm hopefully buying, I will be firstly living on the hard for a year while I ponder and fit out to my requirements and then onto a permanent mooring.

 

So eleccy will always be available, am I right in thinking I can run the shore power lead to a trip box and then from the trip box, wire the boat as you would a house with 240v sockets in and around the place.

 

If say for holidays and weekends I want to go wondering on the river these would need to be fed by a 12v battery bank and suitable inverter?

 

Correct me if I'm wrong so far...

 

My question is... how many plugs can shore power supply? How much output can I expect to be handled in a boat or is it limitless? Say of an evening I had me and my girlfriend had our laptops charging, a tv running and some mains lights. Then the kettle every half hour for a healthy distraction from university...

 

Thanks Jason

 

 

Electric lead to trip box:

 

Effectively "yes" but to qualify what's in the trip box: mains inlet socket --> galvanic isolator --> RCD + MCB (or RCBO(s)) --> sockets and other mains electric devices.

 

Yes if you wanted to continue to access/use the mains (230V) sockets for appliances etc, whilst not connected to an external electrical source, you'll need an inverter. But boats tend to have either mostly 12V devices, or a mix of 230V and 12V devices eg fridge, lights, TV, laptop charger, phone charger, vacuum cleaner, etc can all be 12V items. And you'd have a battery charger (which also supplies 12V current for the 12V devices while connected to the external mains power) to supply these and charge the batteries while you're connected.

 

Electricity isn't measured in number of plugs, but in either power (watts) or current at a nominal voltage (eg amps), and of course the two are related by P = V x I. Typically shoreline supplies 13A at 230V, and typically a TV and laptop (charger) are less than 1 amp each (but check on your particular one). A kettle is probably 2kw so that's around 8 amps.

 

PS regarding the number of sockets, just make sure they're in sensible places and there's enough of them to not need constant plugging and unplugging of various stuff etc. For example our boat had 2 sockets when we bought it (one for TV and one in the kitchen) but I've added 2 more towards the rear of the boat and 2 on the other side, which should do us for a while with the few mains items we use.

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Electric lead to trip box:

 

Effectively "yes" but to qualify what's in the trip box: mains inlet socket --> galvanic isolator --> RCD + MCB (or RCBO(s)) --> sockets and other mains electric devices.

 

This bit has completely confused me, is there any complete set ups I available online for me to see?

 

I understand the 12v thing and didn't think of that as the moving around is more for fun than purpose, my yacht works on that principle although much smaller. Do you mean that the tv is optional 12v or 230 and that you change the plug or that it is wired 12v and the batteries are constantly being topped up by the shorepower through a battery charger??

 

How many batteries (what size) would you put into a bank and what size (an example would be great) inverter would they need to power said drawage?

A kettle is a huge drain then!! WOW

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I can't speak for others but effectively yes, our TV can run off 12V or 230V. It has one of those power bricks, which by chance steps down mains (230V) voltage to 12V. Someone put a plug on this after the step down, and 2 sockets, one connected to the power brick and the other connected to a 12V plug which can be plugged into a 12V socket on the boat.

 

How many batteries? How long do you want the electrical items to last, without charging the batteries eg by shoreline, running engine, solar power etc etc.

 

Remind me of the items you want to power and for how long (have you changed your mind on electric kettle - 99.9% of boaters use a kettle on the hob of a gas cooker).

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Hi Jason, A good help for you to start with would be to have a study on Tony Brookes website WWW.TB-training.co.uk this will cover everything regarding how to set up your boat correctly. The general battery set up would be a single starter type and 3 to 4 leisure and gas for cooking and heating a kettle whilst on the move (electric kettle is big draw on an inverter!). The more simple the set up can be kept the cheaper it would be as far as how much you want to pay for the equipment to run it all.

Hope this helps.

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Thank You both, I will go browse that website.

I think the normal average would be 2 laptops, a tv and lighting.
Apart from that... the only thing I can think of is her straightners and hairdryer which is of no consequence apart from earache to me.

  • Greenie 1
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Thank You both, I will go browse that website.

 

I think the normal average would be 2 laptops, a tv and lighting.

Apart from that... the only thing I can think of is her straightners and hairdryer which is of no consequence apart from earache to me.

Some shore power supplies are as little as 3 or 5 amps. Our first marina was only barely 5 Amos. Some BWML widebeam berths are 32 amps.

When whrking you are not permitted to use the cable used in house wiring with solid conductors. They will fracture in time due to constant movement. Multi strand wires are required. Even though you may never take the boat away from mains power you will at some stage want to sell the boat or your heirs will. So the boat should be capable if running off 12v batteries as well. I recommend an inverter too

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Thank You both, I will go browse that website.

 

I think the normal average would be 2 laptops, a tv and lighting.

Apart from that... the only thing I can think of is her straightners and hairdryer which is of no consequence apart from earache to me.

 

Dont be too hard on your dear lady,get a 12volt hairdryer and gas cartridge hair straighteners!!!

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Dont be too hard on your dear lady,get a 12volt hairdryer and gas cartridge hair straighteners!!!

Even better suggestion, Jason, - buy her a hair trimmer, set it on grade 6, and save all the fuss, bother and expense of expensive hair dressing systems

 

 

 

( wink.png )

 

Edited to add: Jason - here's an authoritative document on boat/off-grid energy - Victron's Energy Unlimited

Edited by Grace & Favour
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Joking aside, you need to take a look around your surroundings, look at the back of every electrical item you have, and gain an awareness of how much power various appliances consume. Anything that heats something, especially water, consumes a lot of power. When you're on a boat (well....on it not connected to shoreline) power costs approximately 10x as much on dry land to generate, and you are responsible for the reliability and maintenance of the thing that generates it. So its worth saving power! Its also very worthwhile knowing how much energy your electrical system has in reserve, and being able to manage it easily. So, think monitoring devices, etc Doesn't need to be complicated - gaining an understanding of how batteries work, and how to use a simple multimeter can go a long way.

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It is a boat so think 12v. You don't need 240v for most of the things you mention. My laptop runs on 12v as does the lights. Water can be boiled on gas. If you can't do without 240v think about a static mobile home and save yourself a lot of problems.

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Probably well worth a trawl of previous posts using the forum search, then ask more questions smile.png

 

Some thinks to look into are:

 

Use of stranded cable instead of twin and earth, and why to use ferrules on the stranded cable ends.

Fitting a galvanic isolator, possibly with status monitor, for shoreline installations.

Why a ring main isn't likely to be essential on a boat.

 

If you do end up doing it yourself it'd be well worth getting a registered spark or someone similarly competent to check it all over before you use it. Maybe best to get a decent basic shoreline install first then look at doing a proper install of the inverter later on.

 

cheers, Pete.

~smpt~

Edited by smileypete
  • Greenie 1
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It is a boat so think 12v. You don't need 240v for most of the things you mention. My laptop runs on 12v as does the lights. Water can be boiled on gas. If you can't do without 240v think about a static mobile home and save yourself a lot of problems.

Do you have that sentence saved somewhere so that you can just copy and paste is as and when the need arises?

  • Greenie 2
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Do you have that sentence saved somewhere so that you can just copy and paste is as and when the need arises?

 

Well, if she does - it makes good sense (the sentence, not possibly the content).

These questions are asked time and time and time again. Nobody seems to bother to research the question(s) nowadays.

Just as long as there are nice folks around who don't get irritated.

 

FWIW

on my boat I have:-

3 pairs of double sockets along one side spread out - bedroom, corridor, lounge

2 pairs of double sockets in the kitchen

2 double sockets in the engine room

Each group has 2 x 5amp 3 pin sockets wired for 24 and 12V

 

I hate trailing leads........

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Do you have that sentence saved somewhere so that you can just copy and paste is as and when the need arises?

Same questions get same answers. Pump out v cassette brings out same replies from usual suspects.

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Why do people get upset about newbies asking questions?....it doesn't mean they haven't searched the forum or other sources for answers first.....isn't a forum about interaction with other members?

 

I put "electricity" in the search and nothing comes up (apart from this post)

 

Anyway, I've found this post quite helpful myself....thanks icecream.gif

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Why do people get upset about newbies asking questions?....it doesn't mean they haven't searched the forum or other sources for answers first.....isn't a forum about interaction with other members?

 

I put "electricity" in the search and nothing comes up (apart from this post)

 

Anyway, I've found this post quite helpful myself....thanks icecream.gif

Sara and Dean

 

I just put 'Electricity' into the search facility (Link) - and it came up with 60 posts

(Just check that you set the correct fields when you use 'Search' - although folks decry it - - it works quite effectively!

 

Of course - if you also did similar searches using 'Power' or 'Battery' - you'd also find a great many more posts

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Sara and Dean

 

I just put 'Electricity' into the search facility (Link) - and it came up with 60 posts

(Just check that you set the correct fields when you use 'Search' - although folks decry it - - it works quite effectively!

 

Of course - if you also did similar searches using 'Power' or 'Battery' - you'd also find a great many more posts

 

Ahhhh thank you G&F have found a massive list now! See you in about 3 days hahahahaa wink.png

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A 1000W at 220V is 4.5A

A 1000W at 12V is 83A

 

20 times more!!!

 

A standard domestic 6A switch at 220V will handle 1300W

A standard domestic 6A switch at 12V will handle 72W.

 

Alex

 

 

For long term survival you should de rate it even further.

 

DC will arc as the contact is broken & wear the contacts so either they weld shut or get dirty & go high resistance causing lots of heat.

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