using a power inverter in a car...what guage wire will suffice?

[MrDudeMan]

i am putting a 740w power inverter in my car and it needs to go further than the length of the wires provide. it has to connect straight to the battery. it says it needs 6 guage wire to go further than 4 feet from the source, and if its closer than 4ft you can use 8 guage wire. well is it going to hurt it if i use 10guage? could i use the WHOLE 10 guage wire per terminal? what i mean is...10 guage wire has 2 lengths of wire in the insulation...could i strip them, combine them, and connect both of them to 1 side? and then use a different cut of wire for the positive terminal?


would that work?

edit, there are 3 wires in it, not 2...so 3 wires for + and 3 for -

 

[woodie1]

You are going to use two 10 gauge wires on each leg? That will work depending on how long the wires will be. You may have to use four ten gauge wires on each leg.

 

[Jhhnn]

Not quite. the current carrying capacity of wire is determined primarily by the cross sectional area.

DC voltage drops rapidly over any distance at all, particularly if the wire isn't big enough. It's lost as heat thru resistance. This can cause all kinds of problems, from poor performance to component burnout to flaming wire. Don't scrimp. If you have to, find a way to move the inverter closer to the battery, make the AC wiring longer.

Please, do the math for yourself. Pi times Radius squared times the # of wires. See how many #10's you'd need to equal one #6.

Table

 

[MrDudeMan]

Originally posted by: Jhhnn
Not quite. the current carrying capacity of wire is determined primarily by the cross sectional area.

DC voltage drops rapidly over any distance at all, particularly if the wire isn't big enough. It's lost as heat thru resistance. This can cause all kinds of problems, from poor performance to component burnout to flaming wire. Don't scrimp. If you have to, find a way to move the inverter closer to the battery, make the AC wiring longer.

Please, do the math for yourself. Pi times Radius squared times the # of wires. See how many #10's you'd need to equal one #6.

Table

according to this table, it should be ok to use 3 10 guage wires, right?

 

[jfall]

just run 4 guage

 

[MrDudeMan]

Originally posted by: jfall
just run 4 guage

i would...but i dont have any and i am leaving tomorrow morning for a road trip at 4:00 AM


heh, that is my problem...

 

[kursplat]

i am putting a 740w power inverter in my car....

i hope it's a good one that can put out an actual 120v instead of alot of 'em that just do a 10-1 conversion.
idle 12.3v in 123v out
winging down the hiway 14.5v in 145v out
good luck

 

[chansen]

Really? Never knew that. I was going to get a cheap one myself from Crappy Tire. Now I have to see what it's capable of.

 

[MrDudeMan]

Originally posted by: chuck340

i am putting a 740w power inverter in my car....

i hope it's a good one that can put out an actual 120v instead of alot of 'em that just do a 10-1 conversion.
idle 12.3v in 123v out
winging down the hiway 14.5v in 145v out
good luck

i got the husky convertor from home depot...i am pretty sure its one of the best so it probably regulates it...hopefully


i got back from my trip today and it all went well. thanks for the help guys

 

[Mark R]

The absolute minimum wire size I would use for such a device would be 6 mm2. You run a genuine risk of overheating the wire if you use anything thinner than that.

If the device is going in that back of the car, then you should aim considerably higher than that - 10 mm2 or even 16 mm2 (although the latter is getting very bulky).

Remember that you need to connect the wire direct to the battery[* see below]. And you MUST protect the wire with a fuse as close to the battery as possible (less than 6 inches). If you are running 2 thinner wires instead of 1 thick one (each one MUST have its own seperate fuse, of a rating suitable for the wire - No higher than 50 A for a 6 mm2 wire).

[*] Many cars now have a fuse between the battery and the rest of the cars electrical system (including the charging system). When the car is running the battery 'floats'; the charging system supplies all the power for electrical accessories - An appliance connected direct to the battery will take all its power through this fuse when the engine is running. If the inverter may ever be used with the car running, you must check that the battery fuse is rated considerably higher than the maximum rating of your device. Blowing this fuse is a disaster and could cause tremendous damage.

 

[KaGee]

Use the 8 ga. Anything smaller could cause a fire.