โApr-23-2018 06:50 AM
โApr-26-2018 11:34 AM
โApr-26-2018 11:08 AM
DrewE wrote:DRTDEVL wrote:
4/0 is 0.46"
2 awg is 0.2576"
2x 2awg is 0.5152"
I believe this will pass the same, if not more, power capacity, while saving money. After all, 4/0 cable is about $4/foot and 2 awg is less than $2/foot. I'll need about 10 feet each for the positive and ground, so this is the difference of $20 in cabling for the same capacity.
Unless I am wrong, then someone correct me. I don't want to burn the thing down.
It's not the same, for a couple of reasons. First, you're comparing diameter rather than cross-sectional area, which of course for a round wire is pi r^2. Here is a nice chart where the math is done for you; 2 AWG has a cross-sectional area of 42.4mm^2, and 4/0 has a cross-sectional area of 107 mm^2. Two and a half 2 AWG wires would be just about equivalent.
The second reason they are not equivalent is perhaps of greater importance. If one of the ground wires were to work lose or break or corrode and have a (relatively) high resistance, you may never notice the difference in performance but the one remaining good one would carry most or all of the current and be overloaded. Even under good conditions there is likely to be some current imbalance as the impedances will not be precisely equal, and it doesn't take very much resistance at all to cause a fairly significant difference for a chunk of wire.
Can't the grounds connect to the trailer frame itself? I wouldn't think you'd need ten feet, just a couple feet at the battery bank and a couple feet at the inverter.
โApr-26-2018 06:24 AM
DRTDEVL wrote:
4/0 is 0.46"
2 awg is 0.2576"
2x 2awg is 0.5152"
I believe this will pass the same, if not more, power capacity, while saving money. After all, 4/0 cable is about $4/foot and 2 awg is less than $2/foot. I'll need about 10 feet each for the positive and ground, so this is the difference of $20 in cabling for the same capacity.
Unless I am wrong, then someone correct me. I don't want to burn the thing down.
โApr-26-2018 05:16 AM
โApr-25-2018 09:14 PM
โApr-25-2018 07:20 PM
โApr-24-2018 08:41 AM
โApr-24-2018 06:21 AM
โApr-23-2018 12:08 PM
โApr-23-2018 11:50 AM
โApr-23-2018 11:18 AM
time2roll wrote:
OK at least fuse the generator start cables with maybe 120 amp fuse.
Assuming it is #4 wire.
Often start cables are not fused but that inverter could melt the wire if the wrong thing gets turned on such as a microwave that pulls 160 amps.
โApr-23-2018 11:16 AM
jkwilson wrote:DRTDEVL wrote:
As I answered in another post, I won't be running this hard. Its for reliability that I will be getting an inverter of that size. I am pretty sure it will run fine on 2 batteries with my setup, since it will usually only be drawing 150w continuous, with the occasional heavier load. Yes, its sine wave.
This model has a junction box in the generator bay with 4 wires, no way to plug the main cable into it (opposite side of RV). I'll check the routing when I pull the back seat panels and see what's going on.
150W output will be drawing 10A or more out of the batteries. Battery life isn't going to be what you are expecting. My off-the-cuff calculation would be 15 hours at best. Inverters are generally only practical for an hour or two of TV watching in the evening after a day on the road unless you have solar panels or a generator to recharge the batteries every day.
โApr-23-2018 11:15 AM
DrewE wrote:
I would guess that there is some sort of a transfer switch arrangement, either an automatic transfer switch, some sort of manual switch (which would probably be incorporated into the AC electrical panel and have more or less clear instructions printed on it), or a socket to plug the shore power cord into that connects to the generator.
Do not hook anything up that relies on you remembering to disconnect the inverter before plugging in. Any such arrangement I can think of would be unsafe and not up to electric codes. Most leave the shore power cord disconnected but energized, for example, which is problematic in itself; a bit of loose metal or a misplaced hand could come into contact with it. If you're at all like me, too, you'll at some point or another forget and cause a fried inverter or similar.
As others have said, a 3000 watt inverter demands a very substantial battery bank. Many of the cheap inverters available have rather optimistic ratings (to put it kindly) and do not take well at all to being driven hard for very long.
What are you interested in powering with the inverter? How much power do you really need, and for how long of a stretch? If it's a lot, it may make more sense to purchase a generator, preferably an inverter generator...or to rethink your electrical usage (e.g. make coffee on the stovetop rather than with an electrical coffee brewer).
โApr-23-2018 11:08 AM