I am rewiring the inverter wiring and have decided to clean up my battery installation. I am installing two busbars, one for positive and one for negative. During the work I noticed there are two 2/0 cables from the positive side of the batteries in addition to the inverter cable. One of these two cables goes towards the front and the other the isolator solenoid. I am assuming the one going towards the front is for the coach wiring compartment under the driver's window.
My question is; should these two 2/0 cables be fused?

I am thinking of installing a fuse in both cables as close to the batteries as possible. Since the cable is 2/0 and I am protecting the four 12 volt batteries I think that a 100 amp fuse should suffice. I can't imagine either drawing any more current than that. Does this amperage seem inappropriate to any one?

I think I would fuse the house batteries to the downstrean load. I have a large industrial type rebuildable fuse in line from my batteries to my selector switch. You can get an idea for terminal fuses from http://www.westmarine.com/weba...ptNum=9&classNum=295
I'm not educated in the use a word to link the site, sorry.

It would all depend on how big the inverter is! if you have a 2000 watt inverter on line and run it near capacity, it will draw well over 170 Amps! (that would be at 100% efficiency)

When using my coffee maker I see nearly 100 amps draw on the +12 volt supply.

I do have a fuse in line but it is rated at 400 amps and really is to protect against any mechanical or direct short on the heavy gauge wire, (I use 4/0) There are other fuses to protect the various pieces of equipment connected to this buss and are lower ratings.

I also got the 400 amp fuse assembly from West Marine

I am rewiring the inverter, which is a Xantrex Freedom 458 Model 30. The rating for this inverter/charger is 3000 Watts. It is currently wired with 2/0 cables which is not correct. I am installing 4/0 cables and shortening the run to a little under ten feet.
The run I am referring to is one that runs from the batteries towards the front of the coach. I assume it is for the coach 12 volt circuits. I will try to verify that when all power is removed. Since it is currently a 2/0 cable I see no need to replace it. A fuse near the batteries would be protecting the batteries so could be as large as the 2/0 could carry. However, I don't know if I really need to fuse it that high. Doing so wouldn't hurt anything since a short in the line would be instantly disconnected from the batteries by the fuse.
I also intend to do a photo posting of the project when it is complete.

Can you locate the inverter closer to the batteries? Drop on 120AC is negligible versus that for 12VDC and the savings on copper is significant.

Ten feet is the shortest I can make the run. Currently the cabling is 2/0 and runs somewhere between eighteen and twenty feet. I have all hardware except the cable which is being donated by someone but will be a week or two from arriving. To get the ten foot run I had to run the cables through the firewall between the engine compartment and electrical bay beneath the bed. I used feed through connectors manufactured by blue sea, models 2205 and 2206.

You will be fine with 10 feet and 4/0 cable. I have the Xantrex RS3000 and I have about 8 feet of 4/0. The voltage drop at full AC load is negligible! Watch the feed through thou, make absolutely sure you have the maximum amount of surface area in contact. Connections can and do loose 50 mv (0.05V) under load.

I did not use feed through on mine, I ran the cable thru the firewall at the back of the bed straight into the Xantrex.

Lance, I like those feed through connectors, good idea! I would have used chase nipples but that is even better....

Somewhere, I have some stepped Micarta or phenolic washers that I used to make feed-throughs with a threaded copper rod and two nuts. Just drill one hole and assemble. Can't remember where I got them, though.