Author Topic: inverter use with out genset  (Read 9510 times)

Offline wayneswirld2

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Re: inverter use with out genset
« Reply #15 on: February 24, 2010, 07:00:07 AM »
Hey Noel, welcome to the insanity.  Like you, I'm new to this, but it sounds like you have much more experience with busses than I do!  I tend to agree with the rest of the guys here, stick with a generator.

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Offline Hi yo silver

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Re: inverter use with out genset
« Reply #16 on: February 24, 2010, 07:49:50 AM »
Sounds like a sub-station on wheels.
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Offline JackConrad

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Re: inverter use with out genset
« Reply #17 on: February 24, 2010, 11:22:52 AM »
What percentage of the time you are spending in the bus will the bus engine be running.  For us, it is less than 10% . The rest we are sitting someplace camping, frequently dry camping. That is why we have a generator.  Jack
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Offline Dreamscape

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Re: inverter use with out genset
« Reply #18 on: February 24, 2010, 04:49:32 PM »

I can't add to what already has been said. However it'll be nice to meet you at the rally in a few days!

We have a genset and no battery bank, but we're hooked up to a pole 99% of the time. The other 1% we use the genset while on the road for needed A/C or whatever else my wife needs. ;)

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Offline 1960eagle

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Re: inverter use with out genset
« Reply #19 on: February 24, 2010, 07:20:44 PM »
Thanks for all the input,will think over and decide what i am going to do.look forward to meeting those who will be at the rally.     Thanks.

Offline Sean

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Re: inverter use with out genset
« Reply #20 on: February 24, 2010, 11:21:22 PM »
We do this all the time.  However, we have an extremely efficient coach, an enormous battery bank, and a 6,500 watt alternator.  Even then, we can only run two air conditioners at a time.

We also have a generator, but we never run it when we drive, only while parked.  If you are really serious about only ever parking where there is a power outlet, you might be able to get away without a generator, but that seems an ambitious goal -- power outlets can be mighty hard to come by in many parts of the country.

In any case, your 3,500 watt alternator is definitely not enough.  That would run maybe one single air conditioner (about 1,700 watts while running; more to start), your fridge, and some miscellaneous stuff.  Anything more than that, and you will be constantly depleting the batteries while you drive.

BTW, 8kW of inverters is impractical on a 12 volt coach.  Some high-end 24-volt conversions have this much capacity (twin 4024s).  We have a single 4kW unit, and it is more than capable of running the two air conditioners plus all the miscellaneous stuff, however, we use a DC fridge.  The sheer size and number of cables you'd need to draw 8kW at 12 volts is daunting.

The only way to really know how much you will need and whether it is possible is to do the math.  Don't forget to account for efficiency losses, which are in the 10%-15% range for DC-AC conversion, and in the 20% range for battery storage and retrieval.  I suspect that if you plan carefully, you can get the total demand down into the 5kW range, and then you can use a pair of stacked 2,500-watt inverters.  You'd still need to add about again as much alternator capacity as you already have; unfortunately, in a 12-volt application, that will mean a second alternator.  They don't come much bigger than 3,600 watts.


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