12v appliances when on shore power

[nb Innisfree]

1 hour ago, Dr Bob said:

How about 4? Quadrouple the back up.

Space

 

The nb final frontier

Edited September 16, 2018 by nb Innisfree

[Phil Ambrose]

10 hours ago, nicknorman said:

I disagree. I am a wise person and I don’t have separates. Most boats have alternate means of 12v charging such as engine or solar. If an inverter or Combi fails, you lose ac power when off shore power, doesn’t matter whether it is a separate or a Combi. If you have a Combi and it fails, yes you lose the charger too but then you have alternate means of keeping the batteries charged so it isn’t a big deal.

 

What is gained from a Combi is seamless switching between shore power and inverter, much less wiring faff, no need for manual changeover switches etc and an ability for the AC system to provide more power than the shore breaker or generator limit.

 

Therefore I consider this “must have separates” argument to be ill conceived and generally just a parroting of something someone else said, without actually having done any analysis of the facts.

Spent 20 years living aboard and analysing the facts and have concluded separates are better. Just saying.

Phil 

[nicknorman]

4 minutes ago, Phil Ambrose said:

Spent 20 years living aboard and analysing the facts and have concluded separates are better. Just saying.

Phil 

Can you show your working?

[Phil Ambrose]

10 minutes ago, nicknorman said:

Can you show your working?

Show your working? Nah I'm retired.

Phil 

[nicknorman]

28 minutes ago, Sea Dog said:

Mastervolt also do separates, so it seems reasonable that their similar quality kit is similarly reliable. Doesn't it therefore follow that each element in one box containing a charger and an inverter is approximately as likely to go wrong as a charger and inverter pair in separate boxes? So  the inverter/charger gets 2 bites of the unreliability cherry and a catastrophic failure of either element is likely to be fatal to the combined unit. Whilst perhaps no less likely, such a failure would affect only one element of the separates. That's the real issue with Combi V Separates: inherently similar reliability per element, but it's the eggs in the same basket thing.  There is, however, other stuff in a Combi which, convenient though it may be, is another link in the chain. In my case (you may recall) it was the transfer circuitry, so my Inverter worked but on only the one of the 2 outputs and the charger didn't work at all.  A quick shuffle of the wiring and a stand alone Ctek charger kept me going, so it certainly wasn't the doomsday scenario some foresee. 

 

I was very happy with my Mastervolt Combi until what I believe was a shore power issue took it out and I was considering replacing like for like.  What I was less keen on was zero technical support from Mastervolt and the diagnosis (let alone repair) procedure being return to the Netherlands with an uncertain outcome thereafter.  Them writing it off, scrapping it and offering a 20% discount on full RRP of a new one didn't seem a good deal. The worst a shore power issue could do to my new Victron set up is damage the charger at about 1/20th the cost of that Combi, although I suspect the stand alone charger is more robust.  The cost in terms of convenience is a hand changeover switch and a lack of a battery support in the case of an inadequate shore power facility (which I never used), so although it's no longer a single switch operation as it was with he Combi I don't feel I have lost out too much.  

 

I certainly don't want to place my flag in the die-hard separates camp, and I don't lament the demise of wind up windows in cars either, but when faced with enforced Combi replacement the appraisal came out in favour of separates for me, and not just because the price was halved.  I expect, in similar circumstances, you'd do a similar appraisal and possibly even reach a similar conclusion. 

 

I don’t think you can say that a Combi, containing as it does the circuitry for a charger and an inverter, is therefore twice as likely to go wrong as each individual separate item (charger and inverter). I’m not quite sure if you are saying that or not.

 

Obviously is annoying if an expensive device like that fails, I can’t remember how old yours was but ultimately things do fail and that needs to be factored into the cost of boating. If your house automatic washing machine failed, would it be a good justification to go back to a separate washer and spin dryer? I think not.

 

Of course there are arguments both ways, but I object to the earlier assertions that (by implication) only stupid people would have a Combi. In reality there is no clear cut best solution, which is why the proportion of newish boats having Combis vs separates are I suspect at best equalish, and most probably Combis predominate. 

Just now, Phil Ambrose said:

Show your working? Nah I'm retired.

Phil 

Show your working as in what it says in maths exams! In other words, describe how you arrived at your conclusion rather than just stating what the conclusion is.

[Phil Ambrose]

5 minutes ago, nicknorman said:

I don’t think you can say that a Combi, containing as it does the circuitry for a charger and an inverter, is therefore twice as likely to go wrong as each individual separate item (charger and inverter). I’m not quite sure if you are saying that or not.

 

Obviously is annoying if an expensive device like that fails, I can’t remember how old yours was but ultimately things do fail and that needs to be factored into the cost of boating. If your house automatic washing machine failed, would it be a good justification to go back to a separate washer and spin dryer? I think not.

 

Of course there are arguments both ways, but I object to the earlier assertions that (by implication) only stupid people would have a Combi. In reality there is no clear cut best solution, which is why the proportion of newish boats having Combis vs separates are I suspect at best equalish, and most probably Combis predominate. 

Show your working as in what it says in maths exams! In other words, describe how you arrived at your conclusion rather than just stating what the conclusion is.

Er isn't that what you did with your assertion that combis are best?

Phil 

[nicknorman]

10 minutes ago, Phil Ambrose said:

Er isn't that what you did with your assertion that combis are best?

Phil 

Well I didn’t exactly say they were the best. But I did say quite a lot about the pros and cons and discussed the issues. In other words, I showed my working!

[Phil Ambrose]

16 minutes ago, nicknorman said:

Well I didn’t exactly say they were the best. But I did say quite a lot about the pros and cons and discussed the issues. In other words, I showed my working!

To be honest Nick, I can't be arsed to fanny around nit picking about what is best and what isn't. Let's face it, no matter what anybody said to you , your opinions are so entrenched that nobody would ever sway you.......a bit like me really.

Phil 

[blackrose]

18 hours ago, Alan de Enfield said:

In effect your battery charger is powering your 12v appliances 

I've always thought of it as the mains powering my 12v appliances. Bit pedantic I know, but the battery charger doesn't create power by itself. 

 

It's a bit like when people talk about their inverter powering mains appliances. No, that's the batteries. All the inverter does is invert. 

[WotEver]

2 hours ago, blackrose said:

I've always thought of it as the mains powering my 12v appliances. Bit pedantic I know, but the battery charger doesn't create power by itself. 

 

It's a bit like when people talk about their inverter powering mains appliances. No, that's the batteries. All the inverter does is invert. 

My pet niggle is when someone says “The cable goes from the isolator to the battery”. No it doesn’t, it goes from the battery to the isolator

 

 

I have a sound engineer mate who insists that the speaker cables go from the speakers to the amps; no they don’t...

Edited September 17, 2018 by WotEver

[Tony Brooks]

10 minutes ago, WotEver said:

My pet niggle is when someone says “The cable goes from the isolator to the battery”. No it doesn’t, it goes from the battery to the isolator

 

 

I have a sound engineer mate who insists that the speaker cables go from the speakers to the amps; no they don’t...

 Er - electron or conventional flow?

[WotEver]

Just now, Tony Brooks said:

 Er - electron or conventional flow?

Source to consumer

[nb Innisfree]

1 hour ago, WotEver said:

My pet niggle is when someone says “The cable goes from the isolator to the battery”. No it doesn’t, it goes from the battery to the isolator

Unless the battery is being charged

[Sea Dog]

10 hours ago, nicknorman said:

I don’t think you can say that a Combi, containing as it does the circuitry for a charger and an inverter, is therefore twice as likely to go wrong as each individual separate item (charger and inverter). I’m not quite sure if you are saying that or not.

 

...

 

Of course there are arguments both ways, but I object to the earlier assertions that (by implication) only stupid people would have a Combi. 

 

No, that's not what I'm saying. Rather that each individual item is roughly equally reliable whether combined or separate, but a box with a dozen similar items in it is more likely to have a failure than any individual item. Of course, a box of very reliable units in it might suffer very few failures. I think that's what others are not necessarily accounting for. 

 

I'm definitely not agreeing with those who make those assertions!

 

 

[Sea Dog]

1 hour ago, WotEver said:

 

I have a sound engineer mate who insists that the speaker cables go from the speakers to the amps; no they don’t...

I'd tend to agree with him because, regardless of which way the wigglies flow, wiring from the load to the supply is good practice where there's any chance of the source becoming live. This is why boaters should always connect shore leads at the boat first then the bollard: this way they're carrying dead cables rather than potentially live ones. Disconnect at the bollard first for the same reason.

[cuthound]

7 hours ago, Tony Brooks said:

 Er - electron or conventional flow?

 

Sound waves (and the electrical impulses from amp to speaker) are sinusoidal, so technically ac, hence the go both ways ??

7 hours ago, WotEver said:

Source to consumer

 

Input to output ?

[WotEver]

4 hours ago, cuthound said:

Input to output ?

Au contraire...

[Bod]

On 16/09/2018 at 12:44, alexmh1985 said:

Thanks guys I thought that was the case but just wanted to make sure! Getting some cables in today

Use trunking, not cable ties to support the wires.

Once the wires are covered, by trim / furniture / e.t.c, then any changes will be impossible!

In 6 months time when you come to fit the hooter, only to find the planned item is not available, the only one that is, requires bigger cables......

I've got to replace a length of cable tied cable, running under the gunnel, thru galley, bedroom, bathroom, engine room, I can only see  the cable in parts of the saloon.  When I feel brave/stupid enough, till then I've got a 3/4 volt drop over 200 foot run.

 

Bod

 

[Alan de Enfield]

23 minutes ago, Bod said:

Use trunking, not cable ties to support the wires.

Once the wires are covered, by trim / furniture / e.t.c, then any changes will be impossible!

In 6 months time when you come to fit the hooter, only to find the planned item is not available, the only one that is, requires bigger cables......

I've got to replace a length of cable tied cable, running under the gunnel, thru galley, bedroom, bathroom, engine room, I can only see  the cable in parts of the saloon.  When I feel brave/stupid enough, till then I've got a 3/4 volt drop over 200 foot run.

 

Bod

 

And once you have installed the trunking include a couple of 'draw-strings' to enable you to pull additional cables (or the ones you forgot).

You cannot 'pull' additional cables if the are cable tied in place.

[Slim]

On 16/09/2018 at 11:43, b0atman said:

A wise person has separates. Separate inverter if needed and a separate battery charger.All eggs in one basket is not a good idea when one has a problem.

A really wise man (or is it one who believes in reduñdancy) has a 100/2000 combi, a seperate 150 amp (actually 2x75 amp) charger, a 1800 w inverter  , a 20 amp charger all on the boat and a 1000w inverter at home. 

Sad really. ??

[cuthound]

12 hours ago, WotEver said:

Au contraire...

 

Depends  where you start, but typically for a power distribution drawing for a building it will stsrt with the incoming supply to the building, then generators, UPS & DC  plant, to the batteries.

[cuthound]

9 hours ago, Slim said:

A really wise man (or is it one who believes in reduñdancy) has a 100/2000 combi, a seperate 150 amp (actually 2x75 amp) charger, a 1800 w inverter  , a 20 amp charger all on the boat and a 1000w inverter at home. 

Sad really. ??

 

Surely you mean a really rich man ?

[TheBiscuits]

25 minutes ago, cuthound said:

 

Surely you mean a really rich man ?

Not after buying that lot! 

[WotEver]

33 minutes ago, cuthound said:

 

Depends  where you start, but typically for a power distribution drawing for a building it will stsrt with the incoming supply to the building, then generators, UPS & DC  plant, to the batteries.

Yeah... it starts with the source and travels to the consumers

[Tony Brooks]

12 hours ago, Bod said:

Use trunking, not cable ties to support the wires.

Once the wires are covered, by trim / furniture / e.t.c, then any changes will be impossible!

In 6 months time when you come to fit the hooter, only to find the planned item is not available, the only one that is, requires bigger cables......

I've got to replace a length of cable tied cable, running under the gunnel, thru galley, bedroom, bathroom, engine room, I can only see  the cable in parts of the saloon.  When I feel brave/stupid enough, till then I've got a 3/4 volt drop over 200 foot run.

 

Bod

 

I agree with the above BUT I usually use loose cable ties when running the cables to keep them all in line and more or less in the correct position but the all get cut off before the trunking cap goes on. I also use plenty of cable ties on my own boat when adding cables to existing VISIBLE wiring looms. It makes  a far neater job one the tails have been cut off that trying to tape clip or wrap the new cable around the loom.

 

Just in case the OP gets the idea cable ties are a no-no.