12v refrigerator

[Kirk]

While you specified that Gary be the one to respond, I'll take the risk of replying anyway. It you don't want anyone else to respond, just ignore this post.

All you need to do is to visit Amazon in order to find an inline fuse holder for the 8 gauge wire. You should be able to find them at mostl electrical supply houses, but I have not shopped one recently. Most such fuse holders that I have purchased didn't come with a fuse in them and even if they should that is no reason to not use a properly sized fuse. Since the refrigerator has a running current of 11A I would use a 20A fuse. A fuse should not be limited to the running current as there is typically a surge current when the load is starting and you don't want that to cause the fuse to open.

 

[paulieboi1]

Thank you for your reply Kirk. I appreciate any assistance I can get. I didn’t want to start a new thread, and wasn’t sure how to post something for everyone. I purchased an 8 gauge inline fuse holder and 20 amp fuse.
I don’t quite understand what you mean about the fuse not being limited to the running current. I will have to investigate that further.
Thanks again for your assistance.

 

[paulieboi1]

While you specified that Gary be the one to respond, I'll take the risk of replying anyway. It you don't want anyone else to respond, just ignore this post.

All you need to do is to visit Amazon in order to find an inline fuse holder for the 8 gauge wire. You should be able to find them at mostl electrical supply houses, but I have not shopped one recently. Most such fuse holders that I have purchased didn't come with a fuse in them and even if they should that is no reason to not use a properly sized fuse. Since the refrigerator has a running current of 11A I would use a 20A fuse. A fuse should not be limited to the running current as there is typically a surge current when the load is starting and you don't want that to cause the fuse to open.

I think I understand what you mean now by not being limited to running current and surge current. So I did get a 20 amp fuse, which should handle the surge.
My other question was about the placement of the inline fuse. Do you think it is okay to have it further away from the power source, since I can’t seem to trace that wiring back to the source? The wiring goes under the flooring and possibly under the vehicle (I haven’t looked underneath yet), but I haven’t located where it connects to the power source. I would assume having a fuse somewhere in the line is better than no fuse at all.

 

[Boat Bum]

My understanding, and way I've done it, is the fuse should be close to the power source, that way it protects the wiring as well; somewhere between 8" - 12". YMMV

 

[Gary RV_Wizard]

Hi Gary,
Thank you for your previous information. I am going to install the 12v refrigerator tomorrow, and would like your expertise on a couple more questions. From what I can tell, the existing 12v wiring is 8 gauge. There isn’t a fuse for it in the 12v panel (I tried them all) and I can only trace the wiring from the refrigerator connection to where it goes under the floor. I’m assuming it must go across to the converter, but I’m not sure. And I don’t know if the existing line is fused, so I wanted to put in an inline fuse. I had to get a heavy duty one because of the 8 gauge wire and the smallest fuse I could find was 20amp. So, my first question is will the 20amp fuse be okay? (the refrigerator is 11amps) The second question is, although it is recommended to put the fuse closer to the power source, would it be okay to put it closer to the refrigerator end of the line, since I can’t seem to trace it to the power source? The old refrigerator was not the original one, and I don’t know how it was connected to the power source.
Sorry to be so wordy, but I didn’t know how else to explain it. I appreciate any feedback you can give me. Thanks again.

This is a "best practice" vs "best practical" question. It's better to have the fuse closer to the source than to the load and better to have it just big enough for the load but equal or less than the wire ampacity. Since you don't know the exact inrush current for the fridge, 20A is a reasonable guestimate for an 11A steady state load. You can always increase the size later if it trips occasionally, but I doubt that would become necessary. As for the location, just do the best you can. At that location, the fuse will protect against any overload caused by the fridge, so only shorts in the wire upstream are a risk. Hopefully there is another inline fuse somewhere along there.

 

[Kirk]

Hopefully there is another inline fuse somewhere along there.

I strongly suspect that there is as it would be very unusual for there to be no fuse between any load and the battery or 12V distribution panel in an RV. Since RV absorption refrigerators are fused for only 3a it is not at all uncommon for them to share a power source with some other appliance. Since you don't know where that is I would just install it near the refrigerator, where it will be easily found if needed. Since the previous refrigerator was 3 way I highly suspect that there is another fuse somewhere.

 

[paulieboi1]

Hi Everyone,
Thanks so much for all your input and help! The 12v refrigerator is up and running! And working like a champ!
Next task: solar power! ;-)