Inverters, how many and why ??

[matsprt]

Ok folks I've been looking hard at two possible buses. One of them only has one 4000 watt inverter. Most everyone else I see has two of some varying size. But still they have two.

Questions are why two ?? What are the downsides to only one ?? (I can think of a couple of reasons but want the input from you experts)

I'm told I can have another added, would one think that a wise move ??

Thanks,

Michael
Getting close to a cure

[ken&ellen]

The reason for multible inverters is simple...two 2500's = 5000 watts, two 3000's = 6000 watts, and two 4000's = 8000 watts of usable power. I have a single 3000 @ 12 volts ( max @ 12 volts by Xantrex ). I plan on adding an additional unit down the road to increase to 6000 watts. Originally, my Liberty came with a single 2500 watt unit and I upgraded to a pure sinewave unit to support my PC & LCD TV. The reason most coaches have multible units is to operate AC's while dry camping. Hope I shed some light. Ken

[Ray Davis]

I know on my CC there are two inverters. In fact the electrical system seems to be split into two 110 legs. It's my assumption that each inverter drives one of the 110 legs in the bus. Things are somewhat logically separated, so that loads are distributed between the two 110 legs.

-ray

[Joe Cannarozzi]

The all electric coaches are power hogs. More is better. What will be running constant on while motoring? Fridge, entertainment center, one A/C, seperate ice maker, washer and drier. Youll need at least that much plus x amount extra reserve. Pretty sure converters take it all into consideration. Someone correct me if Im wrong but I think every 1000watts of accessory is 10 amps of draw. There are new inverters out that are much more efficient, while on they do not run constant. They can sense a power draw and auto on and off. When the time comes to upgrade we will look at these. 4000watts seems plenty, even if it includes running 1 A/C BUT probably not with the washer going and, no redundentcy for back up. If your willing to exersize a little power managment one is probably fine. If you dont you might want another. I dont think we would allow this to hold us up from a coach if everything else fits. Good luck!

[Jon Wehrenberg]

Michael,

I don't design coaches, but if I were to design the perfect coach I would do the following as relates to inverters.

First, I would use two inverters, more for the redundancy than for the total power available. Your worst nightmare is being a long way from home or a service facility and having a major component fail. Your coach goes from being luxury travel to a diesel powered tent.

But I would go further. I would insure that no matter how many inverters my coach had, that in the event of any failure I could restore power to the electrical circuits by being plugged into shore power or running the generator. Further, I would insure that the battery charging feature of the inverter is able to be powered by the generator or shore power.

If the coach has a single inverter it is absolutely critical that getting power to the appliances or for battery charging can be accomplished. Make whoever has that single inverter coach prove to you that can be done otherwise your coach will go dead if the inverter fails.

Going further, if I were to design the perfect coach, and it had two inverters, they would each handle the electrical loads and battery charging duties. In that way a failure of one inverter would at worst force you to do some load shedding, but if the inverters are sized big enough, you will only lose your redundancy if you lose one of the two inverters. There is nothing worse than having two inverters with dedicated circuits so the loss of one shuts down half of your circuits. I'll bet the one you lose will have the devices you need the most.

There is nothing I can think of that would be more frustrating than having a failed inverter and shore power or a running generator and no way to power the devices on the inverter circuits or to charge your batteries. I would never have though of that particular failure mode if it had not happened to a friend who had a brand new H3, a refrigerator full of food, and a failed inverter through which all power had to flow. He was screwed.

[kmuller]

Jon - there are some comprehensive tech articles available at www.zimmermanmarine.com on electrical and other issues. Although they are written from a marine prospective, they have application to coaches as well. If anything they are a bit more serious. On the top center of the home page you will see "Resources". Under that is Tech Articles....that will click you through. At the least, they are great reading. Karl M.

[Jon Wehrenberg]

That is an excellent link.

I skimmed through some of the articles and all I can say is that reading those should be important for everybody on this board.

[Joe Cannarozzi]

Mike, Try this web site


http://www.phrannie.org/phredex.html

[merle&louise]

Michael,

I had an inverter fail while on a trip to Lake Toxaway, TN. I was not aware that the generator would take over but it did! We just ran the generator and all of the accessories worked perfectly. I think that Jon's suggestion about determining if your coach's accessories (especially the refrigerator) will run on generator/shore power if the inverter fails is an excellent one. If the accessories will run on gen/shore power maybe it would be wise to save the money you would spend on a second inverter (you may never need it!). Does your coach have OTR? If so, it seems one inverter would handle most of the other accessories.

Just my opinion.

Tuga Gaidry

[matsprt]

It seems that I had it pretty well figured out. I would have had to verify that the generator and / or shore power would have run everything in spite of a failed inverter but the system works as I suspected.
My current plastic coach has shore power and generator run through the inverter. So a failed inverter makes life difficult.
Now the bad news is that this bus seems to have been sold before I could get over to see it. So onward in my quest of another possibility.

Michael
Still suffering from MPD