Wire gauge and fuse size help

[JCappy]

So I have read, read and read some more but still have not convinced myself of what I really need. I want to make sure I get what's best for my needs without falling short or overkill. My wife got me a refrigerator for Christmas. It's both AC and DC. I can run it in the cab by either option but I would like to be able to run it in the bed. I have been looking at options since my truck does not have the power outlet in the bed. I really don't have the need for anything other than 12V back there.
The refrigerator has a power rated input of 36W on ECO mode and 45W on Max mode. I am looking at installing this panel.

https://www.amazon.com/gp/product/B0DDV1MJ11/ref=ox_sc_act_title_1?smid=AV0WGKM0Z18J2&psc=1

The description states it has 3 USB ports (PD30W+PD30W+QC18W) and a 150W waterproof cigarette lighter socket. I don't ever see myself using all of them at the same time. In fact it would be unusual to use anything other than the cigarette lighter socket for the cooler but it may happen. I know I could get just a cigarette lighter socket but I like having options just in case.
Considering all these factors and the distance from the battery to the rear bedside, I would like some suggestions on what wire gauge and fuse size would be best for this application. I'm not an electrical guru so any input would be appreciated. Thanks

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[CrazyCooter]

I'd do a minimum 10ga and 30A fuse. 8ga would leave room for other future loads in the bed and less voltage drop.

Refer isn't a big load, but can be sensitive to voltage drop over distance. The 10ga would allow you to run up to the max the socket is rated for though.

 

[JCappy]

I'd do a minimum 10ga and 30A fuse. 8ga would leave room for other future loads in the bed and less voltage drop.

Refer isn't a big load, but can be sensitive to voltage drop over distance. The 10ga would allow you to run up to the max the socket is rated for though.

Thanks. I was actually thinking 8ga and a 30A fuse from all of the reading I've done over the past couple of days. Someone said a 20A fuse would work best and blow easier to protect things but I wasn't sure if I should go that low.

 

[CrazyCooter]

Thanks. I was actually thinking 8ga and a 30A fuse from all of the reading I've done over the past couple of days. Someone said a 20A fuse would work best and blow easier to protect things but I wasn't sure if I should go that low.

You are protecting the wire with the fuse located at the battery, so size accordingly. 30-35 for 10ga and 55-60 for 8ga. There are numerous charts and calculators available online for that. Blue Sea has a lot of cool resources.

Question could be.....should you fuse near that questionable imported outlet for say 15a since it's only rated for for such?

 

[wcberry]

It appears your total wattage for the device you are installing is less than 200 which at 12.5 volts, is only 16 Amps. A 10awg wire is more than enough for 20-25' run and 30 amp fuse is fine. 10 awg wire is not recommended for over 30 amps, so hence the 30 amp fuse, you could get away with a 20 amp fuse. If you might add more circuits down the road, then up size the wire and fuse but if not, there is no need to go bigger.

 

[JCappy]

It appears your total wattage for the device you are installing is less than 200 which at 12.5 volts, is only 16 Amps. A 10awg wire is more than enough for 20-25' run and 30 amp fuse is fine. 10 awg wire is not recommended for over 30 amps, so hence the 30 amp fuse, you could get away with a 20 amp fuse. If you might add more circuits down the road, then up size the wire and fuse but if not, there is no need to go bigger.

Yea I don't plan on adding anything else so I may go this route. I already have an inline 20 amp fuse so I would only need the wire. I have plenty but unfortunately nothing in 10 awg. I have a spool of 14 awg but knew that wasn't big enough. Thanks

 

[sl65racer]

Look for the Circuit Wizard app by Blue Sea Systems.

 

[Tennessee Gobi]

I’d stay away from unknown brand outlets and go with proven product. If you just need a single outlet I recommend this ARB Kit.

https://www.northridge4x4.com/part/10900027-arb-fridge-wiring-kit-w-threaded-socket

It has everything you need, 20 feet of 8 gauge wire with fuse holder and a well built 12V threaded socket. It’s available from Amazon as well.

Check the plug on your Refrigerator to make sure it has the screw on connection option. Most do, but many people don’t know that you can remove the outlet plug to reveal the 2 prong screw on connector that provides a secure connection to the outlet.

 

[Radio Guy]

You are protecting the wire with the fuse located at the battery, so size accordingly. 30-35 for 10ga and 55-60 for 8ga. There are numerous charts and calculators available online for that. Blue Sea has a lot of cool resources.

Question could be.....should you fuse near that questionable imported outlet for say 15a since it's only rated for for such?

Those wire size vs current ranges are more for wire heating inside conduit to met the NEC. For vehicle use with a long run I also think 8ga is a good size to start with and I usually upsize to reduce voltage drop since you will usually add more power hungry things in the future.

For a 15ft run power and ground (which is 30ft of wire) and a 30A load, 12ga wire will have a voltage drop of 1.44v or 11.16v at the refrigerator with 12.6v at the battery.

The same run for 8ga wire would be .57v drop or 12.03v at the refrigerator.

For 6ga wire you have .36v drop and 12.24v at the refrigerator.

Grounding the refrigerator may reduce voltage drop on the negative side a little but you get the idea, go big or be sad later.

 

[JCappy]

I’d stay away from unknown brand outlets and go with proven product. If you just need a single outlet I recommend this ARB Kit.

https://www.northridge4x4.com/part/10900027-arb-fridge-wiring-kit-w-threaded-socket

It has everything you need, 20 feet of 8 gauge wire with fuse holder and a well built 12V threaded socket. It’s available from Amazon as well.

Check the plug on your Refrigerator to make sure it has the screw on connection option. Most do, but many people don’t know that you can remove the outlet plug to reveal the 2 prong screw on connector that provides a secure connection to the outlet.

Unfortunately mine is not like that. It does not unscrew as it's one piece. Mine came with 2 different cords. One for AC and the other for DC.

 

[JCappy]

Those wire size vs current ranges are more for wire heating inside conduit to met the NEC. For vehicle use with a long run I also think 8ga is a good size to start with and I usually upsize to reduce voltage drop since you will usually add more power hungry things in the future.

For a 15ft run power and ground (which is 30ft of wire) and a 30A load, 12ga wire will have a voltage drop of 1.44v or 11.16v at the refrigerator with 12.6v at the battery.

The same run for 8ga wire would be .57v drop or 12.03v at the refrigerator.

For 6ga wire you have .36v drop and 12.24v at the refrigerator.

Grounding the refrigerator may reduce voltage drop on the negative side a little but you get the idea, go big or be sad later.

Not planning on adding anything else and I am not going to run 30 feet of wire. Planning on grounding at the rear so that should shorten it up by a lot but I get what you're saying.

 

[Tennessee Gobi]

Unfortunately mine is not like that. It does not unscrew as it's one piece. Mine came with 2 different cords. One for AC and the other for DC.

This one offered by Dometic has 2 outlets, one standard and one of the screw type. It comes with 20 ft of 10 gauge wire with built in fuse holder.

https://www.northridge4x4.com/part/9600024894-dometic-hardwiring-kit-for-dc

You can find it on Amazon as well. I’ve used both the ARB and the Dometic. Both are great options for adding a power point to the bed area.

What brand and model is your refrigerator?

 

[JCappy]

This one offered by Dometic has 2 outlets, one standard and one of the screw type. It comes with 20 ft of 10 gauge wire with built in fuse holder.

https://www.northridge4x4.com/part/9600024894-dometic-hardwiring-kit-for-dc

You can find it on Amazon as well. I’ve used both the ARB and the Dometic. Both are great options for adding a power point to the bed area.

What brand and model is your refrigerator?

Thanks for the info and links. Mine is a 30 QT BougeRV cooler. My wife got it for me for Christmas so I didn't have a choice of the brand. I travel a few times a year to see family in multiple states and she thought this would be good to keep my things cold instead of messing with ice all the time. A friend had one that came to visit me one time so she thought I might like it. I can always just plug it in with the outlet in the back seat but since mine didn't come with the bed outlet I thought I would add something back there so the cooler could stay in the bed. Plus it gives me something to do to my truck lol.

 

[Blade1668]

Thanks for the info and links. Mine is a 30 QT BougeRV cooler. My wife got it for me for Christmas so I didn't have a choice of the brand. I travel a few times a year to see family in multiple states and she thought this would be good to keep my things cold instead of messing with ice all the time. A friend had one that came to visit me one time so she thought I might like it. I can always just plug it in with the outlet in the back seat but since mine didn't come with the bed outlet I thought I would add something back there so the cooler could stay in the bed. Plus it gives me something to do to my truck lol.

Adding a power port in bed is handy to have. From SAE plug, Anderson connector or aux 12 port "cigar lighter" the latter can be a P.T.A coming disconnected or melting down. This is my fix for the cigar lighter outlet fix. The gray connector.

I've bought a spare cord.
A note on them 12v plug ports most are not that good for continuous use. I've melted down more than I want to remember. The dash ones are not rated but intermittent use to 10 amp if that. This little air compressor melted one down and it's plug.

 

[JCappy]

Adding a power port in bed is handy to have. From SAE plug, Anderson connector or aux 12 port "cigar lighter" the latter can be a P.T.A coming disconnected or melting down. This is my fix for the cigar lighter outlet fix. The gray connector.

I've bought a spare cord.
A note on them 12v plug ports most are not that good for continuous use. I've melted down more than I want to remember. The dash ones are not rated but intermittent use to 10 amp if that. This little air compressor melted one down and it's plug.

Thanks for the info. Do you have a link or more info on the grey connector?

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