24V-12V changeover

[Sean]

I knew Sean would have all the answers, ...

Well, for the past two years it has actually been my job to have all the answers (on coach electrical systems), so I do my best to keep current and research everything I write here.

... but personally for my conversion I don't need all the extras 24v would give me.
...

Geoff, you seem very defensive about the choice you've made.  I'm not trying to say you were wrong -- absolutely every coach is different and everyone needs to evaluate their own situation.  Lots of factors can change the balance in one direction or another, including what your own capabilities are (vs. work you will have to contract out) and what pieces and parts you start with.

... I think my setup is cheaper, ...

Here again, this depends on what you start with.  While you are entitled to your own opinion, you are not entitled to your own facts, and what things cost is a matter of fact, not opinion.  Yes, it is possible that certain small 12v systems can be less expensive to install than 24v systems when starting from scratch.  But for most installations, 24v will be less expensive, overall, than 12v when starting with a 24v coach.  There is no substitute, however, for actually pricing out the BOM and doing the math, which is what I recommend everyone should do before making this decision.

...  And those 50DN's are great when they work, but are a hand-grenade waiting to go off and take your engine gear train with them..  I'm glad to be rid of mine. ...

Well, this is a fair point, but I need to point out that it has absolutely nothing to do whatsoever with the choice of 12v or 24v for your house system (or chassis system, for that matter).  A 12v gear-driven 50DN is just as likely to grenade your engine as a 24v model.  So if your argument is that people should remove their gear-driven alternators and replace them with belt-driven ones, that's a whole separate discussion.  Belt-drive alternators are readily available in 24v in a variety of sizes, including, I might add, the belt-drive version of the 50DN, so this really has no bearing on the choice of voltage.

Again, Geoff, I am not trying to argue that the choices you made were wrong for you personally.  Every situation is different.  My role here is to present the facts so that people can make an informed decision.  If I have stated something in this thread that is not factual (without clearly identifying it as my opinion), I'd like to hear about it.  Merely saying that the choice is a "debate" (I believe that's the word you used, even though I disagree with the characterization) does not serve to inform anyone's decision.

FWIW, I have recommended 12v systems on more than one occasion.  Sometimes, that's what the circumstances warrant.  This is a simple matter of math and engineering, and it is very rare, indeed, for the numbers to come out so close together as to make the choice unclear.  I have no bias either way.

-Sean
http://OurOdyssey.BlogSpot.com

[Geoff]

Ha!-- This is getting funny.  I take absolutely no offense when discussing Sean's opinion vs. mine.  I hope Sean has a sense of humor so we can all get along.

That being said, I think that cost wins with going over to a conventional 12v house system over the highly complex 24V system and all the trouble, money, and labor to go to 24v.  This makes 24v a loser unless you are trying to run a hotel out of your bus conversion.

--Geoff
'82 RTS AZ

[bemcadam]

Gentlemen;
I didn't intend to open a large can of worms with this post.  I have read  the posts and believe Sean is right as far as my particular situation is concerned.  I am going to stay with the 24V system that is on the bus now, and put in an inverter for an 18 CF house refrig. and the 2 roof AC units.  Being a heavy equipment mechanic gives me access to plenty of 24V accessories and equipment that can be worked into the conversion.  I want to thank you all for the time and especially for the info you were willing to share.
Thanks again,  all.
Mac

[Sean]

..I hope Sean has a sense of humor so we can all get along.

I try to take nothing said on this board personally.  I do also have a sense of humor; I think many would describe it as "twisted."  

... a conventional 12v house system over the highly complex 24V system and all the trouble, money, and labor to go to 24v.

This is exactly the myth that I am trying to dispel -- that 24v is somehow more complex and involves more trouble, money, or labor.  In fact it is my contention that exactly the opposite is true.  But I think I have bloviated on the subject long enough now, and it would appear that the OP has his answer in any case.

-Sean
http://OurOdyssey.BlogSpot.com

[Geoff]

Bump

[Ed Hackenbruch]

Seems to me that i read something in Popular Science a year or so ago, that because of all of the electronics that they keep adding, new car manufacturers were going to be coming out with 36 volt systems soon.

[Oonrahnjay]

Seems to me that i read something in Popular Science a year or so ago, that because of all of the electronics that they keep adding, new car manufacturers were going to be coming out with 36 volt systems soon.   

      Yes, Ed, I read the same thing ... about a year ago, and in 1999 and 1983 and 1976 and ....

[Jeremy]

Actually I've read about the 36v (42v alternators) idea recently too, along the lines that the automakers want to go in this direction because it would enable them to build simpler and cheaper engines with electrical (rather than mechanical) valve trains. Given the amount of cable in every car built nowadays, a change to 36/42v would probably also mean an enormous reduction in the manufacturers' annual expenditure on copper.

Jeremy