Amperage Confusion

[bigwooo]

I have a parallel E-panel system with dual (parallel) outback FX 2012's.   

I'm located in Mexico and have no one with experience to fall back on for help with wiring practices.  I'm trying to determine what wire size/amp output to supply the main house sub-panel which is located 140 feet from the inverters and main distribution panel.  The outback instruction say that the " wiring from the AC source (which would be my generator?) to the AC loads must handle 100 amps or more"  "All other wiring must handle 60 amps"

I'm assuming the parallel FX's are capable of producing 120 amps? 

I have two questions:

1.  When determining wire size from the utility room main distribution panel, to the main house sub-panel, should I use a figure of 60 amps, 100 amps or 120 amps?  The distance is 140 feet.  I'm assuming I need to wire for 120 amps which is going to require 2/0 wire (ouch).

2.  I currently have wire running from the utility room to my guest house using a 60 amp breaker and the guest house is wired for 60 amps.  After re-visiting the instruction manual for the FX's I'm wondering if I should upgrade this wiring to handle 120 amps?  So far things have been operating fine though.

Thanks for the help.
 

[Watt]

How many amps will you be using?  Meaning what is your maximum load calculated.   And will the wire be in conduit, in the ground or hanging in the air?

[bigwooo]

I can't imagine a max load of over 40 amps, more likely 25 to 30, but I was thinking of wiring for 80 just in case things change in the future.  The wire will be run underground in conduit from the utility room to the house.

[Watt]

I see.

Whatever you decide on current requirments, you could always wire for that and update later if cable costs are too high and are limiting factors.  You would install a breaker at the current source, to protect your wire. 

I wonder though, are you sure you are not referring to the dc side needing the large wire?  I doubt the output would be 20 amps off the inverter and 40 for the pair. 

What size generator do you have?

Also, I assume you need two raceways because you will have two seperate power sources.  So....

[Robin]

The pair of VFX2812's, if that is what you have, can only put out 46 amps continuous. I do not know what generator you have? 46 amps is capable of being handled by 8AWG. You have a fair amount of length though, so to keep your voltage drop reasonable, you will want to use larger wire. You do not need 2/0 wire unless your loads demand it. I suspect your 60 amp service is just fine assuming you used at least 6AWG wire. If it was my house, I would probably use 4AWG with 60 amp breakers.