I have scoured the search items on the board about this, and there's some wonderful bits and pieces of info, but I just need a simple baby talk explanation of what to do with my Vanner. Was just given a 60-50 equalizer today and want to install it in my coach. I know it keeps the batteries charge/draw equal, but how does it relate to me hooking up an inverter to power my coach's 110 system? In other words, is this how I do it:
1. Install Vanner exactly according to directions (connecting wires in order being sure to connect ground last...or first. Can't remember)
2. Install a 5000 watt inverter onto 12 volt source from Vanner?
3. Connect my coach 110 breaker panel to inverter?
4. Viola, I have enough juice to power coach whilst on the road?
This isn't for sensitive electronics, but the roof air, lights, etc. So not going to spend the $$$ on pure sine wave yet.
A 60 amp vanner will not power a 5000 watt inverter . You need 12 volt house batteries for the inverter and hook the vanner up so when you start the bus a relay will energize and put the 50 amps into the batteries. It will not be enough to run the air conditioners while driving down the road. Gerry
Yes, if the question is how to connect a large 12v inverter to the 24v chassis batteries, that's probably not the right approach to take. Unless perhaps you are 100% confident that you'll only ever be running the inverter when the engine is also running - but in that case the proper answer would probably be to start by getting a 24v inverter instead.
Jeremy
Interesting. I knew I didn't know anything about this. Gerry, 50 amps isn't enough for my a/c's? I run them now on 50 amp...or am I confused about 50amp from the inverter
Jeremy, yes our plan is to use the inverter only when driving down the road, but I think I'll message you to get some more info on this. Sounds like I'm approaching it wrong...
Quote from: Scott Bennett on March 26, 2012, 10:30:55 AM
Interesting. I knew I didn't know anything about this. Gerry, 50 amps isn't enough for my a/c's? I run them now on 50 amp...or am I confused about 50amp from the inverter
Jeremy, yes our plan is to use the inverter only when driving down the road, but I think I'll message you to get some more info on this. Sounds like I'm approaching it wrong...
Scott the 50A vanner will not be near big enough to supply an inverter that large.
I'm not an electrical guru so I'll leave that up to one of them to explain.
;D BK ;D
Scott,
A 5000 watt inverter fully loaded is going to pull well over 400 amps at 12 volts, not something you can do with any equalizer.
As simple rule of thumb is to multiply the 120 volt amps by 10 to get the 12 volt amps. Or, divide the watts by the volts to get the amps.
Thus a 1500 watt air conditioner will be 12.5 amps at 120 volts but 125 amps from the battery at 12 volts. The add another 10-15% for inverter losses and other factors.
Got it...so, is there no way to run my fridge and 1 rooftop a/c off the coach alternator/generator?
I installed a 100 Amp Vanner and was trying to run 12v loads such as refrigerator and lights I found the the vanner would go into fault. I ended up putting a 12 volt battery between the vanner and the 12 volt loads all has work well since.
John
Something I will definitely do...the battery as a buffer seems to be a great idea.
Ok, so if I ran a 24 volt inverter off the batteries, I would get a max of 2400 watts? Any way to get more? I would think the alternator/generator of the coach without the load of the original coach climate control would provide enough power for at least 30 amp service???
The limiting factor in the original scenario was the Vanner - do away with this (ie, switch to a 24v inverter) and the world's your oyster. I've no idea how much juice the OEM alternator on your bus can produce - I expect the answer is 'plenty', but someone else will have more knowledge about that.
But be very careful about flattening the batteries by having the inverter turned-on when the engine isn't running. Detroits are quite hard to hand-crank I believe.
Jeremy
I have my bus set up with 24v inverters. I have two 8d start batteries and two house batteries. My front AC is switched to either run off of the inverter or shore power. When going down the road, I switch it over to the inverter and go. Never have a problem with everything keeping up.
Sent from my GT-I9100 using Xparent Green Tapatalk
I highly recommend (particularly for refrigerators and roof-top AC's) a pure sine inverter. "Sensitive electronics" almost always have an internal power supply that could care less about input power, it converts it back to DC and into a switching power supply anyway - what really needs clean power are the motors in your Fridge and air conditioner, so they drive the need for the pure sine. A pure sine will be a lot more efficient running those as well, saving battery power.
I highly recommend a 24 volt inverter for your application - half the DC current means smaller wiring, less fuss and muss. I have a 3000 watt pure sine Samlex inverter to run my roof air from my alternator while driving, it works great.
Brian
Scott I am running the stock 24V alternator, around 270amps I believe. I have a 100 amp Vanner. When I start the bus it switches a 150 amp relay allowing the 100amps of 12volts to go to my 8 golf cart batteries. When cruising down the road, I can run 1 AC unit and the fridge. The fridge does not run all the time so the vanner will keep up with the AC load. Keeping in mind I have lots of house batteries. I am using a SW2412 Xantrex. If the load is to much or the batteries loose too much chargre the gen automatically starts to charge the batteries. This seems to work fine.
Gerry
One of the problems with the pure-sine vs modified-sine choice is that there's no definition of how 'good' the modified-sine output may be.
I've pulled these two charts off the internet at random; both show modified-sine waves, but the bottom one is clearly going to be much nicer to your motors than the top one.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fphysics.usask.ca%2F%7Eangie%2Fep311%2Fimages%2Fclip_image002_0001.jpg&hash=11608f8d584f09ec2f9a312d4268ab5cf678b1ab)
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.min.at%2Fprinz%2Foe1rib%2FDDS%2FImages%2FSineDDS-Chart2.gif&hash=a59eac9f00aa90edfc6d55d05f3b4d5334afbed8)
But, short of hooking it up an an oscilloscope, I'm not sure how you can know how good or bad the output of any given modified-sine inverter might be. In fact, with the possible exception of a small handful of makes, inverters are probably right at the top of my "Don't believe anything that's written on the box" list.
Jeremy
All of these responses are great! The fog is clearing quickly. Thanks SO much guys. Ok, so ditch the Vanner, direct connect a healthy pure sine wave inverter (would love 5000 watts if I can afford it) and go. This of course starts to beg the question, would a quiet diesel genset cost about the same and be less drama? Probably...but on long trips, it would eat fuel....the Detroit is already spinning that big alternator so why not harness right?
The Vanner is great for running all the smaller 12v loads in your bus if you have a 24v house bank to support your giant inverter that you are about to buy...
I run all my 12v loads using the Vanner to equalize the load on the batteries.
Brian
Quote from: Scott Bennett on March 26, 2012, 02:21:24 PM
....the Detroit is already spinning that big alternator so why not harness right?
Partly right...but of course an alternator that's loaded-up driving a big inverter is going to burn much more diesel, comparatively speaking, than one that's not doing much more than float-charging the batteries as you're running down the road.
Jeremy
Quote from: Jeremy on March 26, 2012, 03:05:15 PM
Quote from: Scott Bennett on March 26, 2012, 02:21:24 PM
....the Detroit is already spinning that big alternator so why not harness right?
Partly right...but of course an alternator that's loaded-up driving a big inverter is going to burn much more diesel, comparatively speaking, than one that's not doing much more than float-charging the batteries as you're running down the road.
Jeremy
True dat, but isn't there something I've heard about a big diesel (namely detroit) that pretty much gets around the same MPG even with a loaded alternator? Not sure it would burn more fuel than a genset...but truth be told, I'm beginning to wonder if a good quiet diesel genset is the way to go. Plenty of juice, don't have to idle coach on short truckstop overnight stays...less wear on engine...
I wouldn't ditch the Vanner in any case. (unless you wanna send it to a friend who needs one for one of his charter buses that keeps going thru them)
Now for the question of "just hooking the inverter direct" to the start batteries is also not a "good" idea.
You should have a separate "house" bank for stuff like this. That way if there is ever a problem with inverter/battery set up it won't leave you stranded.
As far as skipping the inverter and just getting a quiet diesel genset goes I'm not qualified the answer that question either. There are many doing it both ways and probable just as many that have both too.
Now clear as mud?
;D BK ;D
Clear as mud :) Definitely will use a separate battery bank....don't need to ruin my two new 8D's and be dead in Flying J.
To summarize:
If I decide to hook up a 24v 5000 watt inverter directly to coach alternator (of course through a separate house battery bank) I'm ok?
I think the answer to the question you are really asking is: Yes, you can charge the house batteries using the alternator while driving down the road by using a continuous duty solenoid.
This is probably a subject for a different topic, but I recommend installing house batteries, and eventually planning and budgeting for a separate method of charging them, whether solar or the quiet generator or both.
To summarize ;D
Yes, you can do that. 5000 watts is a LOT of inverter, the potential surge current can be high, so pay attention to cable sizes and lengths. Like I said before, look for a pure sine inverter.
Brian
You need to evaluate if you really need 5,000 watts of power for your inverter. That is some serious amperage at 24 volts. You're talking 200+ amps of power at full output. The inverter will need to be as close to the alternator and your house batteries as possible. Even with 4/0 cable you're still in danger of voltage loss.
Boy oh boy, what a mess.
Try this: There are two camps, with several sub parties, but here we go...
While under way:
First, those that run the AC via a generator, and second, those that run the AC via a hefty inverter powered by the coach alternator.
The further question is: How do you intend to power the AC when camping?
Typically, we all have a shore cord for campground power.
However, when boondocking,
The first camp simply continues running the generator.
The second camp need to have another way to power the AC other than the coach engine and aternator/inverter set-up. Nobody will be your friend if you have designed your system such that you run the coach engine.
But, the first camp need a way to charge their battery bank, that the second camp have built in to a good inverter.
Additionally, the second crowd may enjoy a load sharing inverter that lets you do magical things with only a 15 amp shore cord that the first camp generator only folks can only dream about.
Everything is a compromise, and each method can be justified by cost and other practical matters by each supporter.
It all depends how you want to be able to manipulate your hardware to be happy and functional. And how you want to spend your ca$h.
Don't bother with the fuel consumption comparison, waste of time.
The Vanner Equalizer doesn't enter into it, as you need to use the coach alternator voltage for these hefty electrical loads. The Vanner has a place to supply your 12 volt needs, however, you have to decide whether to deploy it on the coach chassis or the house banks, depending on how you intend to use 12 volt and whether you will have a fail safe way to be sure you don't drain the chassis batteries while camping... I'd put it on the house side myself.
My bias is to have the house bank voltage match the coach alternator. Why do you want to add a third significant voltage to the already confusing mess?
You need a little electrical primer regarding the relationship of voltage and amperage in order to keep all your apples and oranges lined up.
5 amps at 120 volts, is the same as 25 amps at 24 volts, is the same as 50 amps at 12 volts. So it is no lightweight game powering household items from our DC coach systems.
Wiring is sized to accommodate amperage, so the higher the amps, the thicker the wiring needs to be.
For instance, my Trace 4024 inverter, capable of making 4000 watts of 120V ac power from a 24 volt DC power source takes 0000 cable, or "4 ought" to feed it properly. Bigger than your thumb around the jacket. And some serious circuit protection devices, bigger than the one protecting the bricks and mortar residence.
And to further complicate things on the way to making them easier, it can help to think in terms of watts, since most of your 120V loads will have that kind of rating, and you can compare watts across voltages for the purpose of designing your system big or small enough.
Your big coach alternator, 270 amps at 24 volts, can make almost 6500 watts.
Also, for thinking purposes, in rough terms, your stock coach AC, those two big fans, consumes about the same power from the coach alternator as two roof airs via a good inverter.
Yup, the mud gets murkier and murkier...
happy coaching!
buswarrior
In follow up to what BW has posted. You really need to be clear about how you are going to use your bus, and what you expect it to do for you. You imply overnighting at truck stops while leaving your engine idling. This is a bad idea for many reasons. Personally, I can not see skipping the flexibility that a generator gives you. If a good diesel is in your budget-- fine. If not, use gas or propane until you can get what you really want. If you go with a 24v house bank, then that could be charged on the road through the alternator. The Vanner would then be used to supply your 12v loads while equalizing the bank. If you go with a 12v system, the Vanner could be connected to charge the 12v house bank from the alternator.
A large sine wave inverter capable of running your AC on the road is expensive; probably in the range of buying a generator. A smaller inverter, in the 2500 watt range is a lot cheaper and will run all your normal 120v loads from microwave on down. Sine wave would be nice here, but would not be essential. The inverter can be an inverter/charger or just an inverter. If the latter, you will need a separate charger and some sort of controls for it. Are you cooking with propane or electric? Is your fridge propane or electric? I really think that all the details have to be pinned down before you, or anyone else, can give meaningful solutions.
Yes, in answer to the questions, coach is all electric with the exception of the oven/stove. All electric coaches need juice...mine certainly does. We manage well, but I have a 26 cubic foot digital house fridge. We love our setup, everything is simple, 110 but just need a safe/reliable way to get power to coach when heading down the road. We do not dry camp so we merely need the power for the occasional road trips moving from hookup to hookup. Genset works great, but it's loud and needs me to feed it oil every 10 hours. :-(
Scotty: Like others have pointed out it's a math thing. Fuel for gen set vs cost of batt bank and inverter. Or in your case taking chance on bus battery keeping up on road. Just think a Ideling detroit can burn at least 6 gal a hr deisel while most gen sets run less than 1 gallon of any fuel. Sorry we missed you in florida(had back prob). Best of luck-do it your way. Bob
Um, please, what idling Detroit is using 6 gallons an hour? Not far from 1 gallon an hour for the main engine idling, and the genset will be some fraction of a gallon per hour, unless some over-sized unit with a load on.
My friend Robert has mixed up his typing.
Now, what was I thinking... oh...
A modest battery bank and a good sine inverter will keep that refrigerator going all night silently while you sleep on the road.
A big advantage to a good inverter is being able to use modest electrical loads without having to fire up an engine.
The generator folks have to short run the generator to make popcorn in the microwave.
The inverter folks just do it.
It all depends how you want to spend your ca$h...
happy coaching!
buswarrior
thought I'd get a stirr out of that. Have told by truck friends that is a fair figure on fast idle. so what is it for a two stroke? If travel 60 miles and use 12 gallon that is 5 mile per gallon when traveling. ????? Bob
Government testing and documents I read indicate 0.8-1.5 gallons per hour for most semi trucks. Detroit might be a little worse?? In any case, you think our fridge could run all night on a battery bank? That would be cool :)
Quote from: Scott Bennett on March 28, 2012, 07:14:15 AMGovernment testing and documents I read indicate 0.8-1.5 gallons per hour for most semi trucks. Detroit might be a little worse?? In any case, you think our fridge could run all night on a battery bank? That would be cool :)
Call it 1 gallon/ hour, for 8 hours that's 8 gallons @ $4 gallon or $32. Good points idling (or on a generator)- you park where you want to and go to sleep; using a motel - you find a place to park, go in and check in and give them a credit card, go back, get your bag out of the truck, get into the room, have a shower in the AM (no additional cost), then you check out, carry your things back to the truck, etc., start up, drive back over to the truck stop fuel up and get ready to go. Seems lots of factors.
Do some math for yourself,
Don't go on my word, but to give you an idea of whether you want to go this way, 4 golf cart batteries, a good quality inverter, 24 volt system, and a house frig on 110AC that is already cold, and not being heat soaked by the interior of the coach being at elevated temps, will not harm a battery bank of that size.
Also, I know a busnut madman that could keep a purpose built bedroom cool all night with a roof AC with 8 golfcart batteries.
So, if you get your head wrapped around the electrical, you can decide for yourself what you want to accomplish with the funds you have available, and not follow the crowd.
Try the extensive educational opportunities at this place, as well as a wide array of products and prices:
http://www.altestore.com/learn/ (http://www.altestore.com/learn/)
You can't move any further forward by way of the bus board, you have several evenings of trying to wrap your head around all these electrical concepts. Battery health, sizing the battery bank to run the intended loads, inverter, charger, state of charge meter, and how you might tie all of this together in a system that functions for you, and the rest of those who use the coach without being a monster of a pain in the @$$.
If it ain't simple to operate at the end, you've failed.
Anyway, get reading, see you in a few days!
happy coaching!
buswarrior
A rough estimate is it would take 10 gallons of fuel to go 60 miles which is about an hour of travel. If it takes 10 gallons an hour while moving 5 to 6 gallons an hour idling seems really high. I know that 4 strokes don't take anywhere near that much fuel to idle.
If a truck engine has to run 24 hours a day to provide HVAC for the driver, only a maximum of 11 of those hours can be driving hours to stay legal. There are probably 10 to 12 hours a day when an APU could be used instead. If the APU saved around 5 gallons of fuel per day it would pay for itself in 350 days by my estimate at $4 a gallon. Presumably all fuel used by the APU could qualify for a fuel tax rebate for even more savings.
Some states don't allow idling more than 5 or 10 minutes so an APU is a must if one wants HVAC in the vehicle.
buswarrior. reading.....
I do agree there are a lot of factors. As we travel across the country, we don't stay at camp grounds. We stop overnight at truck stops. Some people hate them, but I've never understood why. I choose a well-lit Flying J, Loves, or T/A and snuggle in somewhere out of the way and we're always treated so nice. But, running a genset during the night disturbs truckers. It's a much more obnoxious noise than the gentle rumble of large diesels idling all night. So in those situations, I'd run battery bank or idle the coach all night. I've done it...we've super-sealed our bedroom area and also included fire-rock sheet rock with a 90 minute fireblock time, so no fumes, and very little heat end up in the bedroom, but we still use a CO sensor and can really fall asleep well to the noise of a DD idling. Love it. Genset is more efficient of course and can be used in other situations. Battery bank of course would be great, but need to learn more about it...will be spending some time to do that...
Scott don
t fool yerself! A ginny running ain't no worse than most refer units.
But on the other hand you are staying in their truck stops as a guest so a noisy ginny may not be tolerated quite as much as a refer unit.
;D BK ;D
Just an update...haven't done much on this yet, but decided to sell the vanners, and put the $$ towards an inverter. That being said, we also this week purchased an 8700 watt surge/7000 watt continuous generator from Horror....I mean Harbor Freight. The thing is much quieter than I thought it would be (76db) and sips fuel....really nice little unit. Very impressed. I read through this thread from top to bottom and really appreciate all of you taking the time to explain things to me so clearly. I know you have to do it 100 times every time some newbie joins the board, but we appreciate it so much. Buswarrior really took some serious time to write his carefully planned responses and I appreciate that...I am intrigued by the concept of a battery bank that can run our energy efficient digital fridge for a 12 hour stint. Already cold, running watts around 170. I understand the amp hours concept and will be shopping around for some golf cart batteries to make this work. Any reason a set of deep cycle 12 volt batteries couldn't work for this purpose?
I believe the 12v deep cycles will work, but it is generally felt the the 6v golf cart batteries will give you more bang for the dollar. AGM are more expensive, but if you can find some used ones, they become more reasonable. Once you have AGM, you will be so happy with the easy care, and lack of gasing that you will not want anything else.
The thing I don't personally like about truck stops is the noise from the trucks idling. I can't sleep to that noise for some reason. Some truck stops do have areas for RVs. I like Walmarts for overnight stops.
I bought a bunch of used 12 volt AGM batteries for my bus off Craigslist for $100 each. They were supposedly for some demonstration project for the state that was dismantled once the demo was over. They are UPS batteries and they seem to work very well. They still hold a charge very well after 4 years.