Wow, really great stuff man. Thanks a lot. I feel like I have a much better understanding of what it is that goes into a system like this.
No worries. Glad to help.
The battery, charger/inverter, and distribution panels will all be very close to each other.
Excellent. Shorter wire runs means less voltage drop so you can usually save a few bucks by not having to buy the next larger size wire.
I had read about wiring gauging and I understand it a lot better now.
Good deal. Now let me drop The Bomb on you.
The Prosine 2.0 is rated to supply 2000w -continuous- output on the AC side, but up to 4500w -surge-. That means that you could potentially draw...:
4500w / 12v = 375a
...from the battery. Good god! So you gotta plug that number in when you are figuring out your wire size and voltage drop - and the fuse to protect the wire.
The Prosine 2.0 manual...:
http://www.xantrex.com/documents/In...e_2.0_User's_Manual(445-0089-01-01_rev-C).pdf
...calls for 250mcm with a 300a fuse for runs of 6' or less, and 350mcm with a 300a fuse for runs of 6'-12'. (page 3-7)
Lemme tell you something about 250mcm wire - to get it in a tight spot you might need tools to bend it to fit. A foot of it can make a nice little billy club. I'm 6'4" and I've got 14" forearms. I can bend 250mcm by hand. 350mcm...maybe. 500mcm and I'll probably need a pipe bender to work it into place (I know this, because I've had to use a pipe bender on 500mcm in the past). It's that beefy.
You are going to need to leave some room at the connection end of the Prosine for that wire since no matter what you won't get a really tight bend on it.
I'll need an in line fuse from the battery bank to the inverter only? Or from the battery bank to the inverter, 12V DC, and 120V AC panel?
Fuses and breakers protect the wire from burning up in case of a short. So wherever you have a hot wire, it must be protected by a fuse or breaker. The rule is to place the overload protection (fuse or breaker) as close to the source of current as possible. That way the maximum length of wire is protected.
Let's say you run 6' of 250mcm between the inverter and the battery. You put the fuse at the inverter end of the wire. Something (like a truck frame ) cuts into the wire -between- the battery and the fuse. Now you've got basically a very high amperage welder running out of control.
The fuse isn't going to blow because the overload isn't running -through- it. The scary monster is going to just keep arcing until either the wire or the truck frame finally burns through and breaks the connection.
Okay, so you put the fuse at the battery end. But wait...the Prosine is ALSO a source of current. What happens if there is a short between the fuse and the Prosine, while the Prosine is putting out power? That's the same deal - the fuse won't blow because the overload isn't running through it.
Fortunately, the Prosine 2.0 has built-in overload protection, so the charger will detect the overload and shutdown. Sweet.
So, on the 12v side, you need a 300a fuse to protect the wire between the battery and the inverter. You need another fuse to protect the wire from the battery to the distribution panel. The distro panel will have fuses or breakers to protect each wire running out of it to the loads.
On the 120v side you'll have a breaker box. In that box, you'll have one breaker that is for the incoming power from the inverter. So you'd run a wire from the inverter to that breaker. That breaker supplies power to the 120v bus, and protects the wire between the inverter and the breaker box.*
(But not really.
If you've been paying attention, at this point you'll say, "But wait, that's not closest to the current source! It's at the wrong end of the wire!" And you're absolutely right. BUT, the Prosine can detect an overload and will shut itself down, which cuts off the current source and more or less performs the same function as a fuse or breaker...so -in this case- we can get away with bending the rule.
So why do we need that breaker? We don't really. We are required to have a disconnect and overload protection. That could just be a normal switch and a fuse, it doesn't actually need to be a breaker. But by using a breaker we get both in one, and since we're feeding a breaker box anyway...)
Then, you'll also have breakers that tap off the bus to feed the 120v loads. The size of those will depend on the size of wire you are running to the loads. Most likely, you won't use over and #12 wire and 20a breakers for those.
*So what size is that breaker and the wire from the inverter to the 120v breaker box? Well, that's a tricky question. The rule is it's supposed to be no larger than whatever breaker is feeding the 120v input of the Prosine (the shore power breaker).
Big RVs generally have 30a or 50a shore power plugs. At a developed camp site with full hookups, there might actually be 30a or 50a receptacles for them to plug into.
But there might not. There might only be 15a receptacles to plug into. So the big RVs usually carry a "dogbone" adapter that plugs into the 15a receptacle, and then they can plug their bigger plug into the dogbone. They have to watch their loads when they do that, or they can trip the shore power's breaker (and maybe have to beg the camp host to reset it).
So, you might use a 30a big RV shore power cord. Or you might use a 15a so you can plug in anywhere. (I would use a 30a shore power cord and a dogbone so I could use a 30a receptacle if it's available.)
But it would suck to limit the feed from the inverter to the 120v bus to 15a, just because the shore power is limited to 15a. That's only 1800w and you'd never be able to use the full 2000w continuous output when running off the battery.
It's a bit of a silly rule if you ask me.
We live in a litigious society and this is a public forum, so the only advice I will give you is this: "Follow the rules".
I will however tell you what -I- would do, and strenuously advise that no one should ever do what I would do. No kidding, if you break the rules then that's on you. I take no responsibility.
Personally, I would ignore the silly rule. I'd run a #10 wire and protect it with a 30a breaker. That's the max the Prosine manual allows anyway. That way, I could get full continuous output from the inverter when running on battery, and still have most (3600w) of the rated 4500w available for handling surge loads.
When on shore power, I could potentially draw more than the shore power can supply - but so what; it will have its own breaker anyway, so if I overload it that breaker will trip.
It's really no different than an RV using a dogbone adapter to plug a 30a shore power plug into a 15a receptacle. You just gotta watch your loads so you don't trip the shore power breaker.
When I'm using my 30a shore power cord and plugged into a 30a shore power receptacle, then I'm not breaking the rule anyway. I'm only breaking the rule when I use a dogbone to plug into a 15a or 20a receptacle.
I also plan on going with a battery shut off switch.
You have to anyway. The Prosine manual calls for a disconnect. You'll want that to be the very first thing connected to the battery. I.e., battery to switch, switch to fuses to whatever.
And I'm not sure if this inverter/charger has a surge protector from the auto transfer switch but I think I might need one.
It has one. From the manual, page 5-9:
"Input Voltage: The charger can operate over the range of 90–135Vac. This wide range allows the PROsine to deliver a maximum current to your batteries even when incoming AC voltage is less than ideal. A built-in surge protector protects the PROsine from surges and spikes on the AC power line."
Well...at least that protects the Prosine itself...it says nothing about if it protects things plugged IN TO the Prosine.
But it does have the ability to detect "good" shore power and it won't switch over from inverter to shore power unless the shore power is "good". (Whatever the hell "good" means...as far as I can see, the manual doesn't say.)
