FT AC & DC Power distribution.

Topic: FT AC & DC Power distribution. (Read 1230 times) previous topic - next topic

FT AC & DC Power distribution.

November 07, 2013, 02:12:57 am

I see few skilled & brave DIY members have done quite a bit with solar upgrades & Converter to Inverter upgrades. I am thinking to change from Converter to Inverter. Initially I would like to figure out which and how big of a inverter to purchase along with required parts to install it myself. I say initially because I would like to leave room for possible future growth ... to be able to later on add couple of solar panels and more batteries. Essentially my goal is to be able to later on power at least one of the roof air conditioners with batteries while driving & not use the generator. First I would like to purchase and install the inverter then get use to using the inverter with current set up. After that see if i want to add more batteries and later on possibly few solar panels. Even though I have done some research, I am having difficulty figuring out how involved the Inverter instillation, mostly wiring will be. Is it as simple as disconnect the wires from Converter and connect them to new Inverter? (probably not).

Please see attached drawing i doodled. Do I get the current set up correctly? if not would you please tell me from your own upgrade DIY experience what I am missing.
1-) 50 amp shore AC power comes in to Coach & from there it is connected via transfer box to AC-to-DC Converter box and House (AC) breaker box.
2-) All AC appliances and outlets are wired to House AC breaker box.
3-) All DC appliances and lights are wired to DC fuse panel.
4-) DC fuse panel gets the DC power from batteries.
5-) Batteries are charged by the converter when connected to shore power or when generator is running or when driving by the engine alternator ( House battery connections to Engine Alternator probably does not go through the converter)

When we add an Inverter we need to run cables from Inverter to how many locations. How do we tie in to transfer box?
I am hopping that migrating from Converter to Inverter would make some of the steps easier? If there is no advantage in migrating and everything has to be done from scratch for the inverter installation then be better of leaving the converter also in its place but disconnected (as back up)?

Thank you for your help,
AL

Re: FT AC & DC Power distribution.

Reply #1 – November 07, 2013, 06:30:07 am

Al, sounds like a sizeable undertaking, I know my coach has 2 transfer switches one for shore and generator power and one for the 2000W inverter. It also has 2 AC panels, both are fed through the gen/shorepower switch, only one of the AC panels is powered by the inverter transfer switch. As far as the AC goes it's going to take a lot of solar panels, batteries and a good size inverter to make that work, if my memory serves me correct the AC will draw 10-15 amps on AC so the inverter will be drawing about 150 amps DC or so, that's a big load for continuous operation I'm sure some of the folks on the forum have a lot more electrical knowledge than me.

Re: FT AC & DC Power distribution.

Reply #2 – November 07, 2013, 07:37:04 am

You might consider running your gen we started using ours more often when we found out the service life was 5000hrs, which i think was the same as yours.

I am no expert. I have 900w and 38a from my solar array. Thats at 100%! 2 gels. Running AC is not an option with my setup and the extra bat, pannels,

Re: FT AC & DC Power distribution.

Reply #3 – November 07, 2013, 07:55:31 am

Your welcome to look at my factory set up that is like bbeame as well.

Hopefully Accusticart will chime in with his thoughts on the two inverters he mentioned to me the other day. He said they would power one AC unit, for a while.

But the expense of adding, extra batteries, inverter, solar panels, solar controller, and an additional transfer switch is huge. Compare that to just touching the generator switch for the few hours when actually driving. We used our generator as wanted or needed and in two years, 7,000 miles spent less than $200 on propane. That cost covered the furnaces, hot water, stove, oven, refer. and generator. But we stored inside, with power, and travel "pole to pole", and have yet to have a chance to dry camp.

The replacement cost for the Iota 75 amp converter that I damaged, was more than the propane for those two years. Additionally the full window tint, with limo tint on the sides and the new legal almost clear on the front windshields really killed the solar heat gains, both while parked and driving.

Would seem the only upside to spending all that money is not hearing the generator run. At a 5000 hour serve life, I doubt many would ever rebuild one. I sold my 20 year old coach with the generator at 350 hours showing. My newer 15 year old coach is showing 445 total hours. If anything I am hard on my generators for not using it more often.

Re: FT AC & DC Power distribution.

Reply #4 – November 07, 2013, 09:02:49 am

Sorry to throw cold water on your proposal, but running roof A/C on your engine alternator to battery to inverter to A/C is not practical.

Few OE alternators will even put out the needed amps. And were they asked to put out max output they would run very hot and cause early failure.

I have upgraded a number of marine and RV electrical systems, but this one, while it can be done, is not practical.

Your propane generator is good for thousands of hours-- use it.

Re: FT AC & DC Power distribution.

Reply #5 – November 07, 2013, 09:19:05 am

Thanks Brett, I had not thought about the alternator trying to keep up.

There was a new boat owner/engineer, that figured out everything to the 3rd decimal point. He figured with all the extra batteries in the new boat, and the inverter, he could run the Cruise Air over night at anchor on Lake Texoma. On paper with worked, but not all night on the lake it turned out. He spent lots of time running his engine, or plugged into shore power. He sold it during that first year.

Another client and engineer added batteries. He called a couple months later to say his new boat was listing 3 degrees to port. We found his extra batteries mounted in the port side cockpit hatch. We suggested he might split them up, or add weight on the other side.

Re: FT AC & DC Power distribution.

Reply #6 – November 07, 2013, 10:08:44 am

Yup, as long as the main engine is running and you are drawing large loads from the battery, the alternator will do (or try to do) its job of keeping voltage around 14 VDC.

If you have a 400 amp alternator (preferably water or oil cooled), that may be possible (with large HP demand from engine). With a Cummins B and smaller alternator, just not reasonable.

Re: FT AC & DC Power distribution.

Reply #7 – November 07, 2013, 10:09:56 am

With enuff money and a good shop, you can install an alternator up to 425 Amp @ 14 VDC, frequently used on firetrucks etc. If your determined to run a/c on roof while saving the generator, yes it can work, but doubt your budget would like it much. Too much $$$ for my taste, $30.00 a day fuel for genset seems like a bargain. No free lunch using the main engine, it will use more fuel too.
For free energy, pull a 24' trailer loaded with a solar setup. No end to what is possible or reasonable ? Of course the reduced mpg towing The trailer needs figured too.
Looks like it costs a lot of money to be Energy smart.

Re: FT AC & DC Power distribution.

Reply #8 – November 07, 2013, 10:29:09 am

Quote from: Dave M – November 07, 2013, 10:09:56 am

For free energy, pull a 24' trailer loaded with a solar setup. No end to what is possible or reasonable ? Of course the reduced mpg towing The trailer needs figured too.
Looks like it costs a lot of money to be Energy smart.

There is a guy doing just that. Is he on this forum, or the Wanderlodge forum? His trailer is completely covered on top with solar, and then he has a huge bank of batteries on the floor of the trailer. He puts his car in the trailer. He boondocks, huge storage, lots of reserve battery power. But as you said, drop your mileage some for the trailer weight.

I towed my 8' wide 18' toy hauler home the weekend we bought our old U225, and I was amazed how little it seemed to matter being back there at cruising speed. Once the GV opened the hole in the wind, the trailer just followed along. Getting everything going was slower of course.

Re: FT AC & DC Power distribution.

Reply #9 – November 07, 2013, 01:56:51 pm

Ok then

It looks like it is going to be Converter upgrade to Iota converter for me; just to replace the older inefficient buzzing, noisy Converter for me. I was only looking to not use the Generator while driving. I am not sure but we don't suppose to operate a LP Gen while driving? ( i know to shut it off before pulling in to a Gas station) but here in TX during summer it is almost impossible to drive 4-5 hours without the roof air running. I was not trying to save the Gen. I will read the instructions but when upgrading a 45amp converter to Iota 75 or 90 amp converter is it just remove the old and connect the new (plug & play) or is it also involved with new cables, etc?

Dave you are right, thanks to you, the 3M Crystalline clear automotive window films we installed on windshield, passenger and driver side windows made the biggest improvement, expensive ($800) but for sure a must here in TX. I will soon do the rest of the windows. In fact I spoke with a window tinting company for our west facing windows for our home and we are thinking to do the same for them. For home windows they use different material and it is a bit cheaper.
Thank you all,
AL

Re: FT AC & DC Power distribution.

Reply #10 – November 07, 2013, 02:07:14 pm

Driving with the generator running is just fine.

Yes, turn off generator and all propane appliances when refueling.

Re: FT AC & DC Power distribution.

Reply #11 – November 07, 2013, 02:28:23 pm

Quote

is it just remove the old and connect the new (plug & play) or is it also involved with new cables, et

It's a straight swap except you will likely have to replace your 15 amp 120v receptacle with a 20 amp (horizontal blade on one side). Here's what it looks like in a 225.
jor

Re: FT AC & DC Power distribution.

Reply #12 – November 07, 2013, 02:32:10 pm

Quote from: Dave and Dolly Cobb – November 07, 2013, 07:55:31 am

Hopefully Accusticart will chime in with his thoughts on the two inverters he mentioned to me the other day. He said they would power one AC unit, for a while....

Dave,
I have no particular expertise in this matter, just what I read on the Internet... There are some folks with a bus Technomadia | Chris Dunphy & Cherie Ve Ard are 'technology enabled nomads' since who went the lithium-ion route for their batteries and are using a Victron inverter. Even if the inverter has enough capacity to power a roof air, of course the battery bank must be up to the task as well... And even the biggest battery bank probably wouldn't work well for long. To do it while driving without drawing down the batteries would require a larger alternator. I don't know if there would even be enough room for solar panels on the roof to provide the necessary charging capacity To keep the house batteries up while running the roof A/C.

However, it occurs to me that if you have the house batteries isolated from the chassis batteries and are not using the alternator to charge them (perhaps via a heavy duty switch or relay), you may be able to use the roof air on the inverter while drawing down the batteries while driving. I don't know how much practical use that is, but it is an interesting thought. There are a couple of links below to the technomad site where they have done the lithium iron phosphate battery conversion and installed a Victron 3 kW inverter. The Victron inverter has some other advantages as regards the charging profiles for the lithium iron phosphate batteries and features power sharing as well. The new Magnum hybrid inverters also have that feature... I am considering both options at this point. The ability to use the batteries (via a power sharing inverter) to supplement a 15 amp shore power connection to provide start up current for the air conditioner or microwave has some valuable practical consideration if you're staying at a friends house without the 30 amp or better hook ups.

There are several threads on the forum regarding lithium iron phosphate batteries and the upshot is that they're fairly expensive, not usually considered ready for mainstream, but are much more power dense for the weight than lead acid wet cell, AGM, or Gel batteries. One of the main attractive features for me is that they can be safely drawn down to a state of discharge of 80% versus the 40 or 50% with the other types of batteries, so you have much more usable capacity as regards the amp hours of the batteries than with the other types. If you could afford it, you could theoretically have a 1000AH of lithium iron phosphate batteries with a usable capacity of 800 amp hours for the same weight as a 500AH AGM battery bank that has a usable capacity of 250 amp hours. is that likely to be in my future? I don't know yet... It's always a matter of competing priorities. I do plan to change out the inverter for one of the two above-mentioned units, and when the house batteries have lost enough capacity then I will certainly look at the then current lithium iron phosphate battery offerings.
Boosted Electrons: The Victron MultiPlus Inverter | Technomadia
Lithium Ion Batteries for RV Motorhome House System - LFP / LiFePO4 |

Don

Re: FT AC & DC Power distribution.

Reply #13 – November 07, 2013, 03:19:48 pm

Don,

For an experiment, you could charge a used but working roof ac with butane R600a and see what the starting and running load is. A lot of cars have done the conversion as well as commercial refrigeration. It only takes very few ounces and the compressor load is much less as the pressure is much lower. Here is a YouTube video of a fellow recharging his system with it. Don't recommend putting all the tools on top of the battery like he does. Recharging The Cars AC With Butane R600a Edit Did a Google search but didn't find anything about fires from using butane.

Pierce

Re: FT AC & DC Power distribution.

Reply #14 – November 07, 2013, 05:10:54 pm

It may be more practical to not use integrated charger/inverters. It will be simpler and cheaper to buy a good 3-stage battery charger and a separate inverter as it will be more in line with what you currently have in place. And can work the same or better than what is found in newer RVs.

Converters by definition have a job to supply power to RV loads, like water pump, lights, refrigerator, fans, etc. Converters are not known to be good battery chargers. A good battery charger will keep batteries charged at the correct voltage without damaging them and will also do a great job supplying power to 12-volt loads.

Mount inverter near house battery bank, maybe in a nearby dry compartment. Connect it to house batteries. Long 12-volt cables should be avoided as they have a higher voltage drop than long 120-volt cables. Run the inverter's 120-volt cable to a place near your current 120-volt breaker box or maybe run the cable to near your TV etc. Or run several AC cables to important places where inverter power is needed.

We do not think it practical to ever run high amp appliances on inverter as they quickly drain battery, which then has to be recharged with generator. So it is better to just start generator to run these items. While driving, some smaller appliances can be run on inverter as battery is not being drained, but pull over and turn RV engine off, batteries will be quickly drained. High amp devices have drains of hundreds of watts, like heaters, microwave, hair dryer, iron, coffee maker refrigerator electric heating element, roof air, etc. Good inexpensive 120-volt cables are AWG-12 Romex 2-wire + ground, from Lowes, etc.

Find a way to switch appliances from shore/generator to inverter. Could be unplugging from one and plugging into other. Or could be a manual switch, like a home stair 3-way switch. Or could be an automatic transfer switch.

Inverter needs to have a remote on/off switch. Since many inverters only have a switch on the unit, some have run a wire from inverter to inside coach connected in series with built-in switch.

Re: FT AC & DC Power distribution.

Reply #15 – November 07, 2013, 06:04:06 pm

The only reason I can see to use a separate inverter and smart charger vs an inverter/charger in one unit is to turn "dirty AC" into "clean AC".

Example: In Mexico, voltage ranges from 102-135 VAC. Too wide a range for most appliances. But within the tolerance of most smart chargers. So, a smart charger can be used to charge the battery and then a PSW inverter used to make quality VAC.

That is the only reason I can think of to have separate units. Were I shopping for one, I would determine the max amp draw I would want to be able to run from the inverter (batteries)-- likely the microwave INPUT. Using a 125% factor, that is the size PSW inverter/charger I would go with.

Features would be smart (3 stage) charging, programming for different battery technologies, battery size and temperatures. A pass through feature (basically a built in transfer switch) is another must have (or you would need to add an additional ATS).

Brett

Re: FT AC & DC Power distribution.

Reply #16 – November 07, 2013, 08:31:18 pm

My thoughts center around the use of the LP Gas generator, they are not designed for 24/7 (My opinion), not to mention it wil burn real close to 1.1 gph on LP, Diesel is closer to .42 gph doing the exact same load and loves 24/7.

Re: FT AC & DC Power distribution.

Reply #17 – November 07, 2013, 08:55:08 pm

Dave,

I agree. But he is asking for recommendation for running the roof A/C while driving. And he has the 230 HP Cummins B engine. Not really practical to put on a high output alternator and huge battery bank. And, no room for a diesel generator.

Re: FT AC & DC Power distribution.

Reply #18 – November 07, 2013, 09:06:52 pm

I installed a 1600-watt pure-sine inverter and a separate charger/converter (Progressive Dynamics 45-A) in our motor home. The charger/converter installed where the old buzz-box went and the inverter is mounted on the aft bulkhead in the little vacuum cleaner compartment under the fridge. Both places have a direct route into the battery compartment on the U225 GV.

1600-watts corresponds closely enough to a 15-a outlet for my purposes. I also have a transfer switch that has not yet been installed. I use smaller inverters around the coach for various purposes. One for the forward TV/BluRay and one for the aft TV/BluRay; both 180-watt pure sine inverters I bought from Amazon. Small, light, but still about 300ma idle current.

I have 600 watts of solar panels (also not yet installed) and I figure my two 8D batteries (plus the start batt) will soak that up... any more solar and I'll have it off more than on. I don't mind running a generator but I am sensitive to the annoyance factor for neighbors. Besides, solar is everywhere. You can't throw $100 bills at the ground and come up with more propane.

Craig

Re: FT AC & DC Power distribution.

Reply #19 – November 07, 2013, 10:01:23 pm

The RoadTrek and EarthRoamer Class B and Class C campers use high output engine mounted generators to provide 110v power and battery charging. The Roadtrek generator puts out 3.5kw at idle nd 5.5kw while driving. It has 8 6v AGM batteries and a 5000 watt inverter. They claim it will run 110v AC overnight. They claim the batteries will charge to full in only an hour or so.

The argument for this concept is that you can run the diesel engine for about 1/2 gal per hour at idle with less noise and polution and weight than a genset.

So is there an engine mounted generator that you can add to the ISM 11 engine or one of the other engines?

Re: FT AC & DC Power distribution.

Reply #20 – November 08, 2013, 01:29:03 am

*** The RV Battery Charging Puzzle « HandyBob's Blog

This is a long read but it appears to be good information.
So far I gave it a quick read until section "SOLAR POWER: Now, if you do decide to spend the money for a solar system" under the (The RV Battery Charging Puzzle.)
I will have to read the rest and then go back and take some notes. I like what this guy is talking about & it is in line with some other stuff i come to know about 6v batteries and key element is to figure out scientifically (literally) charge the batteries to full capacity. This is going to take me some time to figure out and make a shopping list, order & then get my father-in-laws help

(he is the smart one with electric in the family)

Re: FT AC & DC Power distribution.

Reply #21 – November 08, 2013, 02:23:50 pm

Talk to the factory. They offered a "Front AC on inverter option" a year or two back on the Phenix. Included a 300 amp alternator.

Re: FT AC & DC Power distribution.

Reply #22 – November 08, 2013, 04:06:49 pm

Quote from: propman – November 08, 2013, 01:29:03 am

*** The RV Battery Charging Puzzle « HandyBob's Blog

This is a long read but it appears to be good information.
So far I gave it a quick read until section "SOLAR POWER: Now, if you do decide to spend the money for a solar system" under the (The RV Battery Charging Puzzle.)
I will have to read the rest and then go back and take some notes. I like what this guy is talking about & it is in line with some other stuff i come to know about 6v batteries and key element is to figure out scientifically (literally) charge the batteries to full capacity. This is going to take me some time to figure out and make a shopping list, order & then get my father-in-laws help (he is the smart one with electric in the family)

Best to take notice that he is talking about the standard 12 volt wet cell battery, and not GEL or AGM batteries!!

Re: FT AC & DC Power distribution.

Reply #23 – November 08, 2013, 04:11:16 pm

Quote from: PatC – November 08, 2013, 04:06:49 pm

Best to take notice that he is talking about the standard 12 volt wet cell battery, and not GEL or AGM batteries!!

I haven't read all of it yet but I'm not at all sure I agree with everything he writes. Particularly when it comes to MPPT and setpoints. Even for wet cells.

Craig

Re: FT AC & DC Power distribution.

Reply #24 – November 08, 2013, 06:50:38 pm

I read it all. It is important to read it all & then his "inverter Issues 2013" ( I did not finish that yet)
I think he is sharing his experience honestly.
Those who have the equipment installed already can use his experience and check to see if there are issues.
For me it is a good guidance as I am getting ready to find out more about what to purchase and how to install.

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