Inverter problems

[Lester]

In our bus we have a 3600 Trace inverter model 3624. The shore power comes into the bus first through a transfer switch then into a 120 volt breaker. From the breaker it goes into the inverter. The inverter is then wired to four 8D batteries.There is a 120 volt wire going into a distribution panel from the inverter.One wire from this box goes to a 45 amp converter. This converter supplies everything on 12 volt, lights, radio, etc.We have gone through 3 sets of batteries due to boiling them. Now we are told that this converter should not be there and the 12 volt should come directly from the 8D batteries.The inverter is 24 volt. [The inverter was checked by a Trace rep and was O.K.] I am told the converter draws too much out of the batteries. We could email diagrams of the way it is hooked up. Does anyone have any suggestions as to what the problem with the converter might be?
Thanks
Lester

[ol713]

In our bus we have a 3600 Trace inverter model 3624. The shore power comes into the bus first through a transfer switch then into a 120 volt breaker. From the breaker it goes into the inverter. The inverter is then wired to four 8D batteries.There is a 120 volt wire going into a distribution panel from the inverter.One wire from this box goes to a 45 amp converter. This converter supplies everything on 12 volt, lights, radio, etc.We have gone through 3 sets of batteries due to boiling them. Now we are told that this converter should not be there and the 12 volt should come directly from the 8D batteries.The inverter is 24 volt. [The inverter was checked by a Trace rep and was O.K.] I am told the converter draws too much out of the batteries. We could email diagrams of the way it is hooked up. Does anyone have any suggestions as to what the problem with the converter might be?
Thanks
Lester

Hi;
    I also have a trace and a converter for the 12v system.  The converter should use a 115vac input, which it gets from your
    trace.  Your inverter should have a low voltage sensing system that well shut down atomatically.  Your trace should also
    have it's own transfer switch.  If your batteries are being boiled they are being overcharged.  In my case, my solar panels
    were overcharging my batteries.  Still need to adjust the controller. Are the 8d's being charged while the engine is running?
    Might check the engine regulator.
                                                                   Good luck,   Merle.

[niles500]

Lester - if it's the DR model you have a programmable 3-stage Charger, What's it set at? Did you get the remote temperature sensor?

[Hartley]

Why on earth would someone run a converter off their inverter to make 12 volts?

That is just plain silly if not a stupid way to get 12 volts...
The conversion loss has to be greater than just tapping the battery bank at 12 volts.

Please don't take that as an insult. But somebody has been cleaning their ears with toilet paper. (used!).

If you have a 24 volt battery bank. Tap 12 volts off that, Not try to re-invent it using a secondary and large Leech load off the inverter. Let the Trace handle all battery charging and throw that converter in the trash, They are crappy chargers.. They will foul up the charging from the Trace which is much better.....

If you are smoking batteries, That's the reason...

Sorry Guys, It's these kinds of idiotic hookups that drive me crazy. Some whacked out electrician type who doesn't have a clue about battery systems and Inverter systems gets away with hooking up some of the most rediculous contraptions and calls it a feature.

I am really surprised that these things don't cause fires. It's Just wrong.....

[David Anderson]

It seems having a converter is redundant and not needed when you have such a great unit as the Trace.  The Trace should keep the batteries charged sans the converter.  That is what the Trace is supposed to do and is programmable by the user.  The Trace should have available a remote temp sensor that keeps the batts from boiling.  The plug is on the side of the trace and looks like a phone jack.  The sensor sticks to the side of one battery to get its info. 

You should be able to tap 12 volts from your house bank to go to your lighting fuse block.  The Trace manuals are very comprehensive and should show technical drawings how to make all this work.  At least my SW2412 had all the drawings needed to equip the system.  In the past they had a great website with PDF manuals to download in case you lack the appropriate info.  All my experience is with the SW2412, so yours could be somewhat different. 

good luck
David

[buswarrior]

A cautionary note: unless the 12 volt loads are very light and infrequent, you want to add a  battery equalizer to the bank, if you centre tap it for 12 volts. Otherwise, you will be ruining more batteries.

Using the Trace to power a converter to make 12 volts is counter productive, when we can take the 12 volt directly from half the battery bank and add an equalizer to keep the bank balanced.

Sell the converter and buy a Vanner Equalizer at a suitable amperage for your needs. Good transit take-outs at the transit wreckers near you!

I agree, there are too many "experts" out there fleecing folks with their ignorance.

happy coaching!
buswarrior

[Hartley]

Hi All,

I just wanted to clear up something, I got a message from a poster that apparently thought I was attacking them over the converter - inverter issue.

If anyone was insulted, I am very sorry and didn't intend my response to come out that way, It was only about some genius engineer somewhere and a possible misunderstanding of exactly how a thing is or should be wired for best performance
and reliability..

Here is a copy of the message that I sent back via email, Maybe my explanation will help anyone of whom I may have confused or upset....

****************************************

First, Let me say that I didn't and wasn't directing any ill towards you personally. I apologize if it came out that way.
 
The engineering principle is in general terms, You should not need to convert 24 d.c. volts up to 120 a.c. volts just to reconvert it
back down to 12 volts.
 
This is a loss + loss way of getting 12 volts d.c. , Now although if I dug through all the technical reasons and formulas I could prove that without a doubt.
 
If your 24 volt battery bank is grounded to the chassis of your rig so that the Negative battery terminal goes to ground.
 
And if your battery bank is also / or charged by the engine electrical system ( ie: 24 volt coach )  when the engine is running..
 
Then you have a 12 volt supply already available. This would be available at the 1/2 way point from ground of your battery bank.
 
This is assuming that your battery bank is made up of 6 volt batteries or 12 volt batteries. ( series - parallel )
 
(-) Neg of first group of batteries... in a 6 volt arrangement you may have 4 each 6 volt batteries hooked in series
with the last POS (+) terminal being the 24 volt Tap... In that case you go to the jumper between battery 2 and 3 to get (+) 12 volts.
 
You may have 4 batteries or 8 batteries which would be 2 strings of 24 volts in parallel. (best if you have 8 )
 
Or you may have 12 volt batteries. So 2 12 volt batteries in series = 24 volts. or 2 sets of 2 in parallel is 24 volts
You would get 12 volts from the link between battery 1 and 2 in a string. 12 volts on the (+) POS terminal.
 
Now this establishes that you have batteries to pull the 24 volts from and where to find the 12 volt point of your
battery bank.
 
The next issue is your converter. If it is one of the RV type that includes a built in charger and IF you have a 12 volt
line feeding back to a 12 volt battery somewhere ( like tapped off the 24 volt bank ) You risk the built in charger
trying to charge whenever the converter is powered by 120 volt a.c. power ( including if it is powered by the Inverter ).
 
This was the point that I was concerned with. But in reflection I suppose it is possible that a wire may not have been
installed between the CHARGER output and the battery bank.
 
However..... One of my points is that if your Inverter goes offline due to low batteries you will also lose all 12 volt
accessories that are powered by the converter that is getting its power from the inverter. LOSS+LOSS...
 
It cost's more battery power to convert up to 120 and then down to 12 volts to run 12 volt Lighting and accessories.
 
I prefer a system wired so that even if you do not have enough power to run your inverter, You would still have
12 volts available for lighting, radios and accessory use. ( Lights to see what you are doing until you get power restored.)
 
It isn't rocket science, But it sounds like it. Many people will argue the merits of both ways of doing things.
 
There is another element that gets confused into these things and those are called equalizers (ie; Vanner ) that takes
24 volts and balances the charge at the 12 volt point on a battery bank by using a portion of the overall voltage
of a 24 volt system. MCI uses them as do most other 24 volt coaches. Some have them some don't.
 
I run a 12 volt system with a Heart\Xantrex 458 series 3,000 watt Inverter with 150 amp built in charger.
My lights and 12 volt accessories are tapped directly from the same battery bank as the inverter uses.
I have a 150 watt Solar system that also adds power to the battery bank when the sun is shining.
My battery bank is 8 ea 6-volt deep cycle golf cart batteries.
 
I have run the batteries down to the point that the inverter shuts down automatically. However my lighting
all continued to operate although at about 10.5 volts rather than 12.5 which they normally get.
 
If I leave everything off that needs 12 volts all day and don't have shore power or have not used the generator
I still have power after 8 or more hours of solar charging to turn things back on at night. I can stretch power
by letting the solar handle trickle charging and at times running my vent fans on thermostat mode when I am
not using the coach. I don't have to worry about flat batteries or lack of lights in a pinch.
 
I also have a 24 volt Inverter that will be a backup if I need it, But I will still tap at the 12 volt level for lights.
 
The only difference is that you have  a 24 volt system, With that the only addition might be a Vanner equalizer
to keep the batteries balanced. No more "converter" and the inherant problems it can cause...
 
I don't know exactly what you have so saying simply what is happening is difficult at best.
 
Like I said, I apologize if you thought I directed that at you, It was about "genius" engineers...
 
Dave.....

"The DOCTOR is losing his MIND....  ::)DrDave
 

[JohnEd]

Dr. Dave,

It sure wasn't me.

You are very gracious.  Too much so, in fact.  You only sounded exasperated at the hook-up he had described.  As it was going to cost him money and???, I think he is basically grateful for your information.  I would be myself ..... long as it didn't involve my getting hit.

Thank you for posting info I found interesting and informative.

John

[Lin]

I have always been a bit confused by the converter thing.  My first RV had one, but there was only one house battery.  When I put together my first bus, I used a battery bank of 6 golf cart batteries (since changed to 5 glass, 12 volt (whatever they call them) batteries) and ran 12 volt off the battery bank.  I have an independent 3-stage charger that keeps them up.  It has always worked just fine.  I suppose there is a bit of fine tuning of the system that would be good, but the first set of batteries lasted a good nine years, so I don't think I can complain.  Incidentally, the bus I just bought has an converter that runs directly off shore power but does not charge the batteries.  I don't have an inverter or a quality charger yet either.  In due course, I would have thought that I would not be too far off from duplicating the former system.  I suppose an inverter/charger like Trace would be one to consider.