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 > Inverter wire size?

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freewayrandy

'Old Hangtown', Ca

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Posted: 07/16/22 07:22am Link  |  Quote  |  Print  |  Notify Moderator

So new to this, I'm wanting to connect a 425 watt inverter in my rig. What would be the minimum wire size to use for the 12 volt connection?


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Lwiddis

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Posted: 07/16/22 07:47am Link  |  Quote  |  Print  |  Notify Moderator

What’s the distance?

WindyNation’s wire charts will help you… https://www.windynation.com/jzv/inf/choosing-right-wire-size


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Gdetrailer

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Posted: 07/16/22 07:58am Link  |  Quote  |  Print  |  Notify Moderator

Not to be smart, but, what does you inverter manual recommend?

Most inverter manuals will give you a chart with distance and wire size recommendations. Choose the recommended wire size for the distance and include a fuse near the battery sized to that wire size (fuse protects you from having your rig burn down to the ground if the wire or inverter shorts out)..

Small inverters like yours often come with short length of 10ga wire, 425W would be about 30A at 12V so 10 ga would be absolute minimum for short distance (less than 5ft), 8Ga might be better choice if distance to battery is longer..

freewayrandy

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Posted: 07/16/22 08:19am Link  |  Quote  |  Print  |  Notify Moderator

A friend gave me the inverter and didn't have the manual but your info helps. Thanks.

larry cad

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Posted: 07/16/22 08:41am Link  |  Quote  |  Print  |  Notify Moderator

I=P/V

I=AMPS
p=POWER (OR WATTS)
V=VOLTS

I=425/12=35.4 AMPS

10G wire is rated 30amps.

I would go with #8


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2oldman

NM

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Posted: 07/16/22 08:47am Link  |  Quote  |  Print  |  Notify Moderator

Learning what larry said is a good idea when doing any electrical work.

pianotuna

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Posted: 07/16/22 08:57am Link  |  Quote  |  Print  |  Notify Moderator

Don't forget to fuse this new wire. I'd be tempted to direct connect to the battery bank, as the "house" wire is not rated for more than 30 amps.

There may be "inrush" current that may burn out a fuse--unless it is a slow blow. DAMHIK

I'd plan on 40 amps, so #8 is the right decision.


Regards, Don
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freewayrandy

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Posted: 07/16/22 09:18am Link  |  Quote  |  Print  |  Notify Moderator

Thanks for all the info. Pretty lame on electrical here. Inverter primarily for TV. What would be recommended fuse size?

time2roll

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Posted: 07/16/22 09:24am Link  |  Quote  |  Print  |  Notify Moderator

50 amp fuse close to the battery or power source. I agree with #8 unless the distance is long go #6 wire.


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Gdetrailer

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Posted: 07/16/22 09:36am Link  |  Quote  |  Print  |  Notify Moderator

freewayrandy wrote:

A friend gave me the inverter and didn't have the manual but your info helps. Thanks.


Google search the make and model of your inverter and add manual to the end of the search string and by the magic of the wobbly web you most likely will find a online PDF of your inverter manual. You can download the PDF and open it with Adobe reader (free), Open Office (free), Libra Office (free) and even newer versions of MS Office (not free) are able to open PDFs directly..

HERE is a search I did for Cobra 400W manual (you didn't give name and model so I randomly selected a brand and model)..

HERE is the first result of that search which brought up "manualslib.com" which is a huge online library of manuals..

For fuse sizing, you can follow NEC wiring conventions.

10 ga wire = 30A fuse or breaker
8 ga wire = 40A fuse or breaker
6 ga wire = 50A fuse or breaker

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