Inverter Dying?

[mitiempo]

Originally Posted by Ex-Calif

So Xantrax is wrong?

Take a look at the table in mitiempo's post. Although the "guidelines" are poorly explained they talk predominantly about voltage drop, maximum run of 6 feet and "recommended" wire size of 0.

They are doing a little trick however.

1000W / 12 = 83 amps. They are using 10 as the denominator and nominally rating the circuit at 100amps. In my mind they have already built in an 80% efficiency factor.

Actually if it was mine I'd get the inverter to within 3 feet of the battery bank and go with 0 wire.

Your discussion about AC is interesting but irrelevant and confusing.

I always use a factor of 10 when figuring amp draw of inverters as well. It is simpler and errs in the right direction.

I also try and get the inverter as close to the batteries as possible as well. Short DC cables are always a plus.

And I agree with your last line.

[rwidman]

Originally Posted by transmitterdan

............. The AC current output by the inverter has to come from somewhere. The largest energy storage device is the battery. Ergo, the battery has to deliver most of this peak AC current.
.............

The battery (battery bank) supplies all the current that the inverter changes to AC. Not most of it, all of it.

[Ex-Calif]

Originally Posted by Sandero

After reading this thread... and derspite the fact that I don't use large or sustained AC loads.. I will relocate and use 1/0 wire... which seems over kill but better safe than sorry.

Thanks to all who contributed their knowledge.

I think you will not be disappointed with this decision.

I also think most of us are "calibrated" to starter cables being "big." The starter is an intermittent duty high amperage circuit. One can get away with a little smaller gauge wire.

Larger inverters are continuous duty large load items. You can really create problems by undersizing the supply (both cables and battery) to this unit.

Note also somewhere in the manual xantrax recommends keeping the ac loads around 800w. This is a further conservatism by Xantrax and probably a wise one. If you really need 1000w frequently you need to upsize the inverter and probably the battery bank.

[Sandero]

I use myu inverter for fairly small loads... charging a laptop... a cell phone or two... and the lithium battery for the Milwaukee drill... and occasionally a pc monitor and the laptop to watch a flick... and the rare use of a saber saw, a small vacuum or a work light. I don't think these loads come close the the 1000 watts.

[transmitterdan]

Originally Posted by Sandero

I use myu inverter for fairly small loads... charging a laptop... a cell phone or two... and the lithium battery for the Milwaukee drill... and occasionally a pc monitor and the laptop to watch a flick... and the rare use of a saber saw, a small vacuum or a work light. I don't think these loads come close the the 1000 watts.

I think you are right. A PC monitor and laptop probably are less than 250W total.

The vacuum cleaner could be a wild card. Some small vacuum cleaners draw surprisingly high current. A tiny Shop-Vac brand 1 gallon vacuum draws 6A of AC current. It claims to be a 1HP motor which would be about right for 6A. That's about 700W.