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How does a 240v system work re normal domestic appliances


Ian_L

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Hi Everyone,

If I could pick your brains once more it would be really helpful. I've learnt such a lot on this site... its brilliant.

 

I have just put an offer on a 2001 NB and things are currently looking good. However, I will have to re-jig the electrics and will probably pay a pro to do this job BUT... here is my situation:

 

The boat will be on a residential mooring with a 32 amps shoreline. The existing system is 12v with a 600w inverter and I want to upgrade this to a 240v/12v system with at least a 2.5kw pure sinewaive inverter. Ideally, I would like to run a domestic 240v fridge, separate 240v counter-top freezer, small size 240v washing machine plus all the other bits and bobs like laptops, TV, lighting, possible a cooker hood/extractor etc.

 

The boat will be used as a liveaboard most of the time but I need the option to up-spikes and chug away for a few days/weeks when the fancy takes me.

 

Questions:

 

do the 240v appliances run direct off the land line when I am in the marina.

will these appliances run off the inverter when I am cruising

will the diesel engine charge the batts?

Will the system switch over to inverter/12v batts automatically?

 

Is it possible to fit this system about 1K or am I being too optimistic?

 

Or to put it simply... how will this concept work? I know I am using a pro electrician but I need to be able to ask the right questions and not be bamboozled.

 

Cheers

 

Ian

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SNIP>>>>>>>>>>>>>>>>>>..

 

Questions:

 

do the 240v appliances run direct off the land line when I am in the marina.

Yes

will these appliances run off the inverter when I am cruising

Yes, proviso some appliances (usually elecronic controled)do not like it if the supply (inverter) is not pure sine wave

will the diesel engine charge the batts?

Yes,

Will the system switch over to inverter/12v batts automatically?

Yes, if the system is put in place but cheaper if manual

 

Is it possible to fit this system about 1K or am I being too optimistic?

Probably optomistic depending on size of inverter a 'big one' could cost over £1,000

 

 

Cheers

 

Ian

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Hi Everyone,

If I could pick your brains once more it would be really helpful. I've learnt such a lot on this site... its brilliant.

 

I have just put an offer on a 2001 NB and things are currently looking good. However, I will have to re-jig the electrics and will probably pay a pro to do this job BUT... here is my situation:

 

The boat will be on a residential mooring with a 32 amps shoreline. The existing system is 12v with a 600w inverter and I want to upgrade this to a 240v/12v system with at least a 2.5kw pure sinewaive inverter. Ideally, I would like to run a domestic 240v fridge, separate 240v counter-top freezer, small size 240v washing machine plus all the other bits and bobs like laptops, TV, lighting, possible a cooker hood/extractor etc.

 

The boat will be used as a liveaboard most of the time but I need the option to up-spikes and chug away for a few days/weeks when the fancy takes me.

 

Questions:

 

do the 240v appliances run direct off the land line when I am in the marina.

Yep

will these appliances run off the inverter when I am cruising

Yes but you will probably have to turn your inverter on or have a auto crossover switch

will the diesel engine charge the batts?

Ye through a alternator so long as you have got one fitted (It should have)

Will the system switch over to inverter/12v batts automatically?

If you have a auto crossover switch or a inverter/charger with this feature built in

 

Is it possible to fit this system about 1K or am I being too optimistic?

It will cost at least that for the inverter

 

Or to put it simply... how will this concept work? I know I am using a pro electrician but I need to be able to ask the right questions and not be bamboozled.

 

Cheers

 

Ian

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Adam

 

You have the answers to your question, but I fear you have ignored a vital one.

 

You should be fine on the shoreline, but when away form it you should have asked : Can I get my batteries recharged by the alternator? That is a very different question to will the engine charge them.

 

Talk of a large inverter implies you intend to have some hefty 240v loads and (assuming a 12V boat system) you need top divide the quoted wattage of mains items by 10 (or there abouts) to find out the current the inverter will draw from the batteries. Once yopu get into Microwaves, washing machines etc the figures get horribly large.

 

Before you jump in, please, PLEASE do a power/energy audit for your boat and then do the charging time calculations - they can be found on my website. This is not an exact science, but having some idea about engine running time is better than just trusting to luck - that way lies ruined batteries and unreliable systems.

 

Email off group if you want more advice/help.

 

Tony Brooks

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You didnt put a link.

 

Or you could look in last months Canal boat and inland waterways and it shows you what to do. If you work out that your alternator can't charge your batteries in time then it opens a hole new can of worms like having a extra alternator wind/solar or a generator. If youre not careful the cost could mount up.

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You didnt put a link.

 

Or you could look in last months Canal boat and inland waterways and it shows you what to do. If you work out that your alternator can't charge your batteries in time then it opens a hole new can of worms like having a extra alternator wind/solar or a generator. If youre not careful the cost could mount up.

 

 

Terrific and very helpful response from everyone (I knew it would be!) Many thanks!

 

Cheers

Ian

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You didnt put a link.

 

Or you could look in last months Canal boat and inland waterways and it shows you what to do. If you work out that your alternator can't charge your batteries in time then it opens a hole new can of worms like having a extra alternator wind/solar or a generator. If youre not careful the cost could mount up.

 

 

Deliberately no link because that looks a bit too much like self advertising to me, but it is in my profile. I am also not sure about the charter.

 

TB

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Deliberately no link because that looks a bit too much like self advertising to me, but it is in my profile. I am also not sure about the charter.

 

TB

 

If it were about advertising your courses, then I might agree.

 

However, as your pages are an absolute mine of useful information, given away free of charge, I can't see the slightest problem with posting a URL if it is relevant to a query.

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In your situation i would go for a inveter/charger combi unit, which works just like a computer/server UPS system if you familuar with that.

- With mains, it runs the 240 things of the main, and charges the batterys.

- Then when the mains drops, it seamlessly switches over to inverter mode. Till your batterys are flat...

- Many of them can also 'mix' the mains input, with the inveter output allowing you to draw peak currents the exceed your shorline rating.

 

Which also brings me to the point that no normal shorline will be more than 16amps, and most are fused at much less (8/6 even as little as 2/4amp)

 

 

Daniel

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In your situation i would go for a inveter/charger combi unit, which works just like a computer/server UPS system if you familuar with that.

- With mains, it runs the 240 things of the main, and charges the batterys.

- Then when the mains drops, it seamlessly switches over to inverter mode. Till your batterys are flat...

 

Isn't this seamless switching actually a disadvantage of combis? Unless you regularly check your supply while on shore power, if the RCD trips on the bollard for some reason or if you just run out of prepaid credit on the meter, the first you might know about it is when your batteries die? I suppose a battery monitor with a low voltage alarm would solve this.

Edited by blackrose
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Isn't this seamless switching actually a disadvantage of combis? Unless you regularly check your supply while on shore power, if the RCD trips on the bollard for some reason or if you just run out of prepaid credit on the meter, the first you might know about it is when your batteries die? I suppose a battery monitor with a low voltage alarm would solve this.

 

Or switch the inverter off.

 

Gibbo

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Or switch the inverter off.

 

Gibbo

 

I thought if you were charging from mains with some of these combis, the inverter automatically cut in if there was any drop in mains and you can't stop that happening without turning the whole thing off. That's what I thought but perhaps I misunderstood. Anyway, I have separate charger & inverter

Edited by blackrose
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I thought if you were charging from mains with some of these combis, the inverter automatically cut in if there was any drop in mains and you can't stop that happening without turning the whole thing off. That's what I thought but perhaps I misunderstood.

 

I've never seen one where you can't switch the inverter off separately from the charger/transfer (crossover) function.

 

Anyway, I have separate charger & inverter

 

 

Me too :)

 

Gibbo

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In your situation i would go for a inveter/charger combi unit, which works just like a computer/server UPS system if you familuar with that.

- With mains, it runs the 240 things of the main, and charges the batterys.

- Then when the mains drops, it seamlessly switches over to inverter mode. Till your batterys are flat...

- Many of them can also 'mix' the mains input, with the inveter output allowing you to draw peak currents the exceed your shorline rating.

 

Which also brings me to the point that no normal shorline will be more than 16amps, and most are fused at much less (8/6 even as little as 2/4amp)

Daniel

 

Hi Daniel,

The shoreline has a 32 amp supply. It's a new marina.

 

Ian

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Hi Daniel,

The shoreline has a 32 amp supply. It's a new marina.

Blimey, that is a bit extreme. Never seen that before.

- I just you have to have 32amp ceeform plug on the side of your NB to match that then.

- And then a good old 32 -> 16amp unfused addapater for 99% of the narrowboat on the system.

 

 

 

Hey hoo, demand prevokes supply and all that!

 

 

Daniel

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I thought if you were charging from mains with some of these combis, the inverter automatically cut in if there was any drop in mains and you can't stop that happening without turning the whole thing off. That's what I thought but perhaps I misunderstood. Anyway, I have separate charger & inverter
As Gibbo says Mike, that is not how combis work. I have a Victron combi which includes the auto changeover feature. There is a three position switch on the unit. Off, Charger, Inverter.

 

Off is obvious. "Inverter" means that when on a shore line, power is used to both charge batteries and supply other usage, automatically balancing between the two according to the demand for the latter and in the very unlikely situation that other usage become higher than shore power can deliver, the unit will augment shore power with battery power though clearly one wouldn't want to do that for long. If shore power is disconnected, this is where the auto changeover comes in, with very rapid switching to battery supplied inverter power so that virtually uninterrupted supply continues to whatever appliances were in use.

 

"Charger" means that the unit is charging batteries only, when on shore power, and not supplying mains power to the outlets on the boat. This position is generally for use when away from the boat, precisely so that no battery drain can occur should shore power cease for any reason. All that would happen is that the charger would stop charging. Also, with the switch in this position the unit delivers a straight through mode for mains on the boat so that the outlets are supplied direct from shore power.

 

As far as I can see a combi inverter/generator/auto changeover like this is the ideal solution for those who want mains inverter power whilst off a shore line and also use shore power at times. Similarly the incoming mains can be supplied from a small generator too when not on a shore line, simply by plugging it into the same mains inlet socket on the boat though internal switches on the Victron have to be altered in order to accommodate the lower amperage of a generator or alternatively an add-on manually adjustable input controller can be purchased.

 

However for anyone contemplating using a generator with a Victron combi, note that it works only with top quality generator output like that from Honda inverter/generators in the "suitcase" range, not with cheaper clones that superficially appear similar or other inferior quality output models.

 

I can't see much point in having a separate inverter and charger these days, given the availability of high quality combi units from the likes of Victron or Mastervolt, the only two brands that I would ever consider. The only reason to have separate units as far as I know is that if one fails you don't need to replace the whole thing and thus it would probably be cheaper in such circumstances. But given the quality of modern equipment from manufacturers like these, how likely is failure? In my opinion any potential advantage like that is outweighed by the versatility of a combi, which in addition provides the auto changeover device too.

 

regards

Steve

Edited by anhar
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