Wire Size Assistance Requested

WVI

Adventurer
Well, on the BluSea calc ii's giving me 18 ga wire with a min fuse size of 5amps/ recommended 10amp.
I wasn't sure what to put in for the run time, so I entered 30 the 60 min based on a guess of hourly run time.
I'll still go a bit heavier with the wire.
 

john61ct

Adventurer
Well, on the BluSea calc ii's giving me 18 ga wire with a min fuse size of 5amps/ recommended 10amp.
I wasn't sure what to put in for the run time, so I entered 30 the 60 min based on a guess of hourly run time.
I'll still go a bit heavier with the wire.
You used round trip length?

What V drop?

Never any harm in going thicker for future proofing!

I usually keep only 3-4 spools on hand, and of course round up not down.
 

WVI

Adventurer
10/4 john61.
I'm only running 10-14ft RT.
I'm not to worried about voltage drop.

I try to keep wire on hand.....at least old odds and ends. As today, I will run to town to get wire for this project.
I wish I had bought some spools years ago..... I go for small items these days and think, "has it really been that long ago" based on the cost of items now....like fuse holders..I'll prolly delay my install based on local prices and order online.
 

Photobug

Well-known member
DRP & Dreadlocks, I figured on doing the partial run length if I ground to chassis.

You are going to have to run a wire. Why not just run two. That way there is no corrosion or screw backing out issues. Buy yourself a spool of 12 gauge stranded primary wire. if you want to do this right. Use crimp fitting with heat shrink.

The inline fuse size should be for the wire size or the weakest link in the system. whoever mentioned fusing for the 12v outlet had a good idea. If you start burning out 15A fuses in a cigarette lighter outlet, something is wrong. In the case of sensitive equipment think of radios, etc, not sure a fridge falls into sensitive equip status but I would hate to burn one out. The fuse should be as close to the battery as possible.

The 'cigarette lighter' 12 outlet is also a source of weakness. Consider an Anderson Power Pole or more reliable connection point.

The reason you calculate the load using the program is for voltage drop. The Blue Seas calculator is aiming to have the voltage drop to be less than 3%. Most batteries have a battery saver cutoff function. It cuts off at a present setting to make sure you have amps to start the car in the morning or don't ruin a house battery by running it too low. If you go cheap on the wire or have a bad grounding connection, your battery may be at 12.3 volts but may be showing 12.1 at the fridge and therefore cut-off in the middle of the night and wake up to warm milk or even worse warm beer.

I would guess you invested $1000 give or take for a fridge. Don't scrimp on the wiring at this point. The difference between doing this right and fudging it should only be $20, $50 if you switch to Anderson Connectors. You will have to invest $200 in connectors and crimpers but worth it in the long run.

 

john61ct

Adventurer
Yes standard ciggie sockets are IMO a dangerous abortion, avoid like the plague for anything important, or that you use regularly. Never more than 5-6A and only for short periods, as in a few minutes. Even then they are risky, an inherently poor design!

Blue Sea has a nice socket design that twist-locks with the matching plug, but will also accept standard ciggie plugs for smaller (
Also the BMW/ Hella/ Merit/ Powerlet "Euro-style DIN" (ISO 4165) style is very robust.

Anderson plugs for high amps, for me my standard, for almost all power connections.

If you standardize on one of the last two types, there are adapters for guests, temporary use of devices with standard ciggie plugs.
 

Photobug

Well-known member
Yes standard ciggie sockets are IMO a dangerous abortion, avoid like the plague for anything important, or that you use regularly. Never more than 5-6A and only for short periods, as in a few minutes. Even then they are risky, an inherently poor design!

Blue Sea has a nice socket design that twist-locks with the matching plug, but will also accept standard ciggie plugs for smaller (
Also the BMW/ Hella/ Merit/ Powerlet "Euro-style DIN" (ISO 4165) style is very robust.

Anderson plugs for high amps, for me my standard, for almost all power connections.

If you standardize on one of the last two types, there are adapters for guests, temporary use of devices with standard ciggie plugs.

I have both in my wiring setups. CIgarette and Andersons. A year or so ago when wiring i listened to your disdain for Cig plugs be felt it was easier because most 12v things come wired that way. I felt for lights and fans, etc it is just an annoyance if they do not work 100%. I have marine grade twist locks all around but unfortunately not the twist lock plugs.

Two day ago I had to wiggle the plug to my lights to get my lights working in my truck. I would not want that unreliability in a fridge setup.
 

john61ct

Adventurer
An intermittent connection's sparking can melt plastic surrounds even at relatively low current rates

Starting a fire is possible not far away from that.

Just because car lighters invented in the 1880s had that particular shape 8-D
 

WVI

Adventurer
Good Points. It would be easy to just run two wires. I'd forgotten to consider that the unit does have a low power shut off!!!
I did by enough good wire.
The socket I'm using is a good quality twist lock type.
I didn't realize the Anderson plugs could be had in a compact size. I've never used them.
Thanks
 

NatersXJ6

Explorer
Good Points. It would be easy to just run two wires. I'd forgotten to consider that the unit does have a low power shut off!!!
I did by enough good wire.
The socket I'm using is a good quality twist lock type.
I didn't realize the Anderson plugs could be had in a compact size. I've never used them.
Thanks

The voltage drop is the main driver for fridge wire size. I can tell you from experience with using the ARB fridge wire kit with A Dometic CFX 28 that the wire was undersized. The LVD kicked in unless the vehicle was running. It sucked. Expensive lesson.

I’ll throw a +1 on landscape wire. You get the advantage of paired cables and very good UV resistance on the insulation. That can be important in vehicle applications.
 
  • Like
Reactions: WVI

Photobug

Well-known member
The socket I'm using is a good quality twist lock type.
I didn't realize the Anderson plugs could be had in a compact size. I've never used them.

The problem with twist lock outlet is it does no good without the twist lock plugs, consider upgrading the fridge to that.

The only problem with the Andersons is you will need to invest in a specialty crimper for it. But once you have it, you are good to add it when needed.
 

john61ct

Adventurer
genuinedealz.com for custom cables, top quality, charge $1 per crimp

or ask around lots of shops will let you use their crimpers

I think the good-enough clone crimpers PowerWerx sells are only $50 or so?
 
  • Like
Reactions: WVI

john61ct

Adventurer
The problem with twist lock outlet is it does no good without the twist lock plugs
Well known-good makers rate better current capacity than cheap-Chinese stuff.

I think Blue Sea is up to 10A?

But yes of course the easy-disconnect failure is only corrected with using a better connector design, anytime I buy something with a ciggie plug it gets chopped off first thing.

Unless it's a low current item only occasionally used for short periods and the wire can't be removed at the device end if I care about the warranty.
 

Photobug

Well-known member
Well known-good makers rate better current capacity than cheap-Chinese stuff.

I think Blue Sea is up to 10A?

But yes of course the easy-disconnect failure is only corrected with using a better connector design, anytime I buy something with a ciggie plug it gets chopped off first thing.

Do you use Anderson for all plugs?

I have a decent crimper still find Andersons the hardest to work with. They are great once the crimp is made but a hassle to make.
 

john61ct

Adventurer
I have a collection of over a dozen different crimpers, if purchased new would cost at least $3500, some weigh 40lbs and are over a yard long.

Need to use the right one for each connector type,

to verify milspec gas-tight results use calibrated standard pull tests.

Andersons are closest I use as a "universal standard", but only where their use is appropriate.
 

Forum statistics

Threads
185,798
Messages
2,878,294
Members
225,352
Latest member
ritabooke
Top