| Author |
Message |
Henry van de Graaf (Hcvdg) (65.138.119.221)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 28, 2001 - 11:40 pm: | |
I'm updating the electrical system of my 4106 and would like some data.
50A of 240V (12KW of 120) seems to be enough for most (if not all) but I would guess that the full 50A isn't needed at all times. I am interested in the KWHs used per day by those that "suck" 50A juice.
I'd like to size my battery bank/inverter(s) to provide 50A power when only 30A power is available (most times).
Thanks, Henry |
DrivingMissLazy (65.207.109.111)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 29, 2001 - 9:47 am: | |
Henry,
First you have to understand that you only "suck" out of the service the power you need to operate the appliances that are turned on. However, the 50 amp service permits you to operate just about anything in the bus at one time such as two or three A/Cs, the microwave/convection oven, toaster, hair dryer and all the other small convenience items. If you are in a campground with only 30-amp service, then you have to practice energy conservation.
Many of the newer campgrounds, especially west of the Mississippi have 50-amp service available. However, non of that really has anything to do with your battery bank. You can not operate A/Cs on batteries unless you have a truckload of them.
The main purpose of the batteries is to permit you to boondock for a few days without the necessity of having to run the genset. If you are in a climate where A/C is required, then you have to run your genset.
INVERTER SIZING. Unless you are maintaining the bus A/C system, the inverter should be sized to operate a couple of A/Cs while you are on the road. This eliminates having to run the genset while driving. A 4000-watt, true sine wave inverter such as the Trace SW-4012 is ideal. You also need a 300-amp alternator on the bus engine.
BATTERY SIZING. If you plan on doing some boondocking, then my suggestion is to put in as many (within reason) as space and funds permit. I have four 8-D’s and wish I had a couple more, but no room for them. I would recommend going to the 6-volt gulf cart style deep cycle battery. A recent post indicated that the Sam’s club battery carries a three-year, free replacement warranty and a seven-year pro-rated warranty. I would recommend a minimum of eight and preferably twelve of these.
In addition I would recommend a digital battery tester from NAPA for about $100. I have found it to be 100% accurate after testing thousands of batteries and it will pay for its self the first time you are really trying to determine if a battery is bad or not. And they do go bad. I have found several brand new batteries that are bad. The equipment I manufacture (uninterruptible power supplies) typically uses from fifty to a couple of hundred batteries, so I have a lot of experience testing for bad batteries.
I hope that this long winded dissertation will prove of some benefit to you and others on the board.
Richard |
Steve Fessenden (63.27.88.79)
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Votes: 0 (Vote!) | | Posted on Saturday, December 29, 2001 - 10:23 am: | |
You won't want to run an actual 50 Amp service from a battery bank and inerter. The advantage to what you propose is that you will never have to switch off one circuit before switiching on another. Your Inverter will help with the occasional simultaneous operation of loads that exceed the park's 30 Amp service. Your wife will love it.
You will want to put all your inverter run devices on one leg of the 240 volt service. |
DrivingMissLazy (65.207.109.111)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 29, 2001 - 11:00 am: | |
My recommendation is that nothing in the bus be wired for 240 volts including the generator.
The 120 volt wiring should consist of two separate 120 volt circuit breaker boxes. The inverter would be connected to one of these boxes with any loads on that box that need to operate from the inverter. Typically kitchen outlets as well as bathroom, bedroom and living area outlets on their own breaker in that one breaker box.
Each A/C should be on separate breaker boxes.
The 120 volt generator output should connect to the inputs of both breaker boxes.
The 240 volt shore power would have each 120 volt leg connected to separate breaker boxes.
The dogbone 50 amp to 30 amp adapter connects both of the 240 volt shore cord legs together so that you have power on both breaker boxes when connncted to a 30 amp or lower shore power connector.
This configuration requires a transfer switch that automatically re-configures the the internal wiring so that the genset or shore cord are never connected at the same time. BTY, I think RONTHEBUSNUT has some low cost automatic transfer switches.
As you indicate, the load sharing capabilities of the inverter is great when you only have a 30 amp or lower shore cord service.
It also would be great while driving at low speeds and the engine alternator is not putting out sufficient amps to operate the A/Cs from the inverter.
Richard |
Henry van de Graaf (Hcvdg) (172.183.73.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 30, 2001 - 2:05 am: | |
Thanks for all the words so far. Though it may not seem so- I have looked into this. [Bus Jock, Poop sheets, living on 12V, Ample Power, et al] The equipment costs a bunch so I welcome all input.
The plan as it stands is to...
Remove:
(2) La Marche 40A converters
(2) 8D House
(2) 8D Start
Stock Regulator
7.5 Kohler gas genset (when diesel is ready)
Install:
Heart Interface 2000R (monitor/regulator) $370 used
Heart Marine 3000W (hooked to 12V bank) also has 15A charger for start bank. ($500 used)
Vanner (or other fine brand) equalizer 60A (or more)to link 12V and 24V house batts. (still looking for good price)
Trace SW4024 hooked to 24V house bank (still looking for a deal, don't want to spend >$1800 used)12) Concorde GPL-4C AGM batteries for 24V house bank. 660 AH, 24V at 20hr rate.
(4) Concorde GPL-4C AGM batteries for 12V house bank. 440 AH, 12V at 20hr rate.
(2) Excide Red Top AGM start batteries, 800 Cold Cranking Amps
(2) Two cyl. Kubota diesel ZB600-C driven 125A 24V alternators (Army surplus)
Needs: a charge controller/regulator to regulate the two 24V alternators and the output from the Vanner.
May install: A 4KW belt driven generator to one of the Kubotas (about $400)
Design intent: A "no worries" design
1) Be able to maintain a comfortable temp (say 75) when in the Deep South at 90° and 90%, with four people, and hooked to a 30A "power hose" (I have two 14 KBtu roof airs).
2) Use bus alternator to charge (3 stage) batteries.
3) Don't want to (ever) water batteries (not required with AGM)
Current configuration:
Factory Conversion wired for 50A
(4) position 50A switch in cockpit (Off, Shore, Gen, not used)
Bus is wired with (2) 120 legs and (2) 50A DC (house) legs. with a roof air on each leg.
Still need help on:
1) I plan to hook an inverter to each of the two 120V legs (one roof air on each). Is this a good plan?
2) I'm not sure how the equalizer current is regulated (I need to read Jock's stuff again). |
DrivingMissLazy (65.207.109.130)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 30, 2001 - 10:47 am: | |
Two cyl. Kubota diesel ZB600-C driven 125A 24V alternators (Army surplus)
I would caution you to be extremely careful about using military surplus equipment.
My forty years in dealing with different gensets that I have purchased from military surplus is that they typically contain many unique parts that are not available from the commercial market place. The controls are typically built to serve a multitude of requirements, difficult at best to understand and trouble shoot of course no factory service is available. Simple components such as voltage regulators, control relays and other control components are generally not available anywhere.
Replacement engine components and controls may also be very difficult to obtain. On a military contract for large numbers of engines, the engine manufacturer has to meet certain mil specs and general contractor requirements and the components are generally not standard OTS (off the shelf). Even the generator itself will probably not be standard and it is next to impossible to get it re-wound or find replacement brushes.
I once purchased about forty surplus military engine gensets. I eventually got about six working by cannibalizing the other units and never was able to sell more than one or two due to the complexity of the controls and the unavailability of repair parts.
Believe me, if you are out in the boonies somewhere and you have problems, the ability to get it repaired are nil and none. Even with all my years’ experience on all types of gensets, I would run, not walk away from these units.
It appears that you are planning on spending an awfully lot of money on inverters and other components in order to eliminate the requirement for a commercial AC genset which can be repaired (except for Generac) in any moderately sized town. Just my $.02 for what it is worth.
Richard |
Henry van de Graaf (Hcvdg) (172.180.209.147)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 30, 2001 - 11:11 am: | |
Thanks Richard for the thoughts.
The Kubota diesel ZB600-C engine is the one used in the Kubota "low boy" 6.5 KW generator so I'm hoping that major parts will be available. I am looking for a shop manual for the Kubota.
Cost wise, I think the system will come in less than a Onan quiet diesel but I'm keeping an open mind.
Henry |
CoryDanes RTSII NE/IL (4.17.253.66)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 01, 2002 - 1:49 pm: | |
My offering to you is to consider 24v from the battery to inverters. You will have to run huge cables to power a 12v inverter and it gets hotter from working harder and the cables have to carry DOUBLE the amp capacity then that of a 24v battery cable would. And then think of the heavy duty switches, connectors, etc that have to support/carry that high amperage, not to mention solenoids if charging from the bus alternator, you have to buy. If your bus was already wired for 50amp, it must have had a heftier design than you are planning to revise to.
For example to get 30 amps from your breaker box you would need an estimated 300 amps flowing through the 12v cables from the Battery to Inverter, not considering start-up currents or line loss. To supply that same 30 amps from your breaker box would require an estimated 150 amps flowing through the 24v cables from the battery to the inverter. I hope you have considered these numbers as well. To carry the 150amps on 24vdc would be half the size (though still sizable) of what you MUST run for the same loading supplied by 12vdc.
Above 24, a 48v battery to inverter would be better but I dont think it is practacle or even available.
If you were building an RV with its few circuits, I'd say 12v is great, go for it because there is virtually no load but if you are considering full timing and a live-in status, go the extra step to 24v from the battery, cables for 24v and inverter. You won't be sorry. Just something else for you to research, LOL - cd |
CoryDanes RTSII NE/IL (4.17.253.66)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 01, 2002 - 1:54 pm: | |
OK, I can do some numbers but not always products, What is AGM in batteries??? Do I wanna look at this too?
Oops, I see he has a 24v battery system too, ok so just use the above posting as information-LOL
Guess I should find my glasses. Hmm and I have one right here that can hold a few ounces of beverage too - LOL cd |
FAST FRED (209.26.87.116)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 01, 2002 - 2:54 pm: | |
I don't have my copy of Da Book ,
but dont thing that 800A CCA is anywhere near enough to start in clod weather with out a load of pre heat.
Anything under 40F takes a bunch of amps ,
not usually avilable from that style batts.
FAST FRED |
Steve Fessenden (63.27.88.58)
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Votes: 0 (Vote!) | | Posted on Tuesday, January 01, 2002 - 3:29 pm: | |
With the Vanner equalizer you can run your 12 volt loads from the 12 volt terminal of a 24 volt sytem. Then you can use all the same size batteries for your 24 and 12 volt system since it becomes one battery system with two output voltages. If you have two engine driven Alternators they can both now be 24 volt, one for house one for bus. Redundancy and simplicity. If one fails on a trip, you connect the other to charge all batteries.
You can, on many generators, change the internal generator connections so that it puts out only 120 volts. You don't need 240 volts from your generator since your transfer switch or plug and outlet system will prevent you from connecting the two 120 volt legs of a 240 volt park system. You still need two breaker panels or one 240 volt panel using the two sides as two 120 volt legs which can be supplied by either 240 volts overall or the same 120 volts to both sides.
The plug and outlet system I mentioned above means you have a 50 Amp 240 volt grounded plug that supplies the panel through a short cord in a closet or bay. You have a 50 Amp outlet for generator and one for the shore power 50 Amp cord. Fred Hobe also added a 50 Amp outlet for a 30 Amp shore power cord, because a 30 Amp cord is much, much lighter to handle when all you have available is 30 Amps. You cannot therefore plug into but one of the two or three plugs at a time, so you cannot cause a short. |
Jayjay (207.30.180.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 01, 2002 - 11:46 pm: | |
Sounds like a lot of good advise, and the only thing I will add is to be VERY CAREFUL with high amperage capabilities. When you parallel 4 800A. batteries you still have 12 volts but 3,200 amps of arcing ability. Use high quality, brand-new wire of the proper size and insulation class,(use Nat. Elect. Code) and support it and fasten it down securely. A short on that kind of system will BLOW a hole in your bus and can produce a self-sustaining arc that will only extinguish after the batteries have heated to the explosion point. Just like dynamite (literally), so be very careful, and good luck. Cheers...JJ |
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