Wire gauge for inverter

workingdog

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I hoping to put a 800 watt (1600 peak it says on the front) inverter in my rear quarter. What size wires do I need to run from the battery.

Peter
 
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800 watts is about 60 amps, so you will want to be sure your alternator can keep up with the demand. You should be OK with 10 gauge wire mounting the inverter in the engine compartment, 8 gauge if you are mounting in the rear. Do an internet search on automotive wire gauge and you will see lots of information.
 
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I put a DC amp probe on + lead to the cigg lighter when I had an inverter plugged in to a laptop computer and it was pulling 4.5 amps @ 12volts DC . for this load ... Look at the input requirements . there should be sticker with the specs on it .
input voltage ; 12vdc/ ? amps or watts
output voltage 120vac/ 800watts continuous/ 1600 peak surge
 

workingdog

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Thanks for the info, it hadn't occurred to me to mount in the engine compartment, but that is a good idea.

I lost the manual years ago, but I'll look online and see if I can find it.

Here's a site I found with a table of wire sizes. These are some big wires.

Inverter Size
< 3 ft
3ft - 6ft
6ft < 10ft
400 Watts
8
6
4
750 Watts
6
4
2
1000 Watts
4
2
1/0
1500 Watts
2
1
3/0
2000 Watts
1/0
2/0
250
2500 Watts
1/0
3/0
350
3000 Watts
3/0
4/0
500

This table looked right in the composition window, but then all screwed up in the thread - sorry.

I never intend to use it at max capacity, it's just an inverter I bought years ago that I was planning on using so I don't have to purchase a new one. But I supposed under sizing the wire would just be asking for trouble in the future.

Peter
 
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There are a LOT of different sizing charts for wire gauge, and most of the residential ones
deal with heating- as in, how hot will the wire get after x hours!

Others deal with voltage drop- how much loss is acceptable over the run.

Car stereo guys use unusually heavy gauge wire because while their average
power draw isn't all that much, they really can't afford the voltage drops.

An inverter's a lot like a stereo, in that it's not a continuous load- it's pulling pulses out
of the battery. So a relatively small voltage drop hurts your maximum current delivery.

And distance is a killer at high amperage- it makes good sense to keep the high current
DC wires short, and extend the high VOLTAGE low current wires from there.
So it makes good sense to put the inverter as close to the battery as you can.
Then you can use nice heavy short leads and not have to worry about it.

My version is (eventually) to put the aux battery and inverter in the back, where the inverter
can be protected and the battery tucked out of the way underneath.

Oh, and make sure your ground's as good as your supply!

(if it was me, I'd use something like 2ga up to maybe 10 feet, and go 0 after that. But
that's kind of a gut instinct)

t
 

NCFJ

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You are better off mounting the inverter as close to the battery as possible because you can use a lighter gauge wire than mounting it in the rear. You can then wire in 12 gauge wire anywhere in the rig with no problems.
 

workingdog

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The battery in the back is also a good idea. It gives complete isolation from having use of the inverter drain the starting battery. Also, the wire required to charge it could be quite small in comparison. I'll have to look for mounting spots.

Peter
 

mwalls54

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I went to best buy and bought the largest amp wiring kit they had. Came with a inline fuse and terminals. I run a 2000 watt inverter in the back of mine and it runs fine. I also have dual batterys and a 200 amp alternator.
 

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