12 volt fridge fuse?

[josephsiracusa]

i purchased a used boat recently and noticed that the 12 volt fridge is connected directly to the deep cycle without a fuse in between. i followed the positive wire from the rear of the fridge straight to the deep cycle and its certain there is no fuse installed. the fridge appears 20 years old or so, and its about 2 feet tall by 1.5 feet wide.
1. is this correct?
2. should there be a fuse on the positive side close to the battery?
3. if fuse is needed what amp size fuse should be used?
any help would be great.

 

[Barnacle_Bill]

Re: 12 volt fridge fuse?

Yes there should be a fuse. There should be a tag on the unit that has the amp draw. Use a fuse a little higher than what it says.

 

[josephsiracusa]

Re: 12 volt fridge fuse?

i was looking all over fridge for tag and doesnt have one.......do know what to do....i know a fuse needs to be installed though without fridge specs cant determine the size amp fuse? what size do you suggest at least for the sake of having the fusg? let me know please thanks

 

[josephsiracusa]

Re: 12 volt fridge fuse?

i was looking all over fridge for tag and doesnt have one.......do know what to do....i know a fuse needs to be installed though without fridge specs cant determine the size amp fuse? what size do you suggest at least for the sake of having the fusg? let me know please thank

 

[Thalasso]

Re: 12 volt fridge fuse?

Get yourself a clamp on ac/dc clamp on meter. 6 Function Mini Digital Clamp Meter at harbor freight for $10-11. you don't need anything like a Fluke meter that people are going to tell you to get. This will tell you what your drawing. Google your make and model. Maybe it will give you the specs on what it's supposed to be drawing. Whoops. Twenty years old? Might be time for a new one regardless. If it's twenty years old that's saying something. Not any that i have heard about lasting anywhere near that long

 

[bruceb58]

Re: 12 volt fridge fuse?

Get yourself a clamp on ac/dc clamp on meter.

Going to be tough finding a clamp on meter that measures DC, at least for a reasonable price.

 

[sam am I]

Re: 12 volt fridge fuse?

Note/est. gauge/type of wire, look up ohms/ft of said wire, use cheap $5.99 analog Radioshack special voltmeter on 1V full scale setting for example, turn fridge on, wait for compressor to kick on, measure/note voltage drop across 1/2/3 ft. of the wire, I=V/R :noidea: Probably be well within 10%

 

[UncleWillie]

Re: 12 volt fridge fuse?

The fuse is sized for the AWG wire size. Not for the Load/Appliance on the end of it.
The battery fuse is to protect the wire. The fridge will have has its own fuse internally.
It is perfectly fine to install a fuse smaller than rated, but not larger.
The wire gauge will be marked every foot or so on the wire.
If it is 14awg wire, use no more than a 20 amp fuse, 8awg = 40amp, etc.

 

[Thalasso]

Re: 12 volt fridge fuse?

Going to be tough finding a clamp on meter that measures DC, at least for a reasonable price.

6 Function Mini Digital Clamp Meter Item #96308 Harbor Freight. Sale: $10.29


Clamp-style multimeter lets you make instant tests and measurements without disconnecting wires. Use this clamp-on multimeter to test amperage up to 400A. The digital multimeter features an easy-to-read LCD display and an automatic zero adjust for precise and accurate measurements.
•Test AC/DC voltage, AC current, resistance, diode and audible continuity test
•Features an easy-to-read 3-1/2 digit LCD display
•Resolution: 1999
•Data hold retains information after test
•Automatic zero adjust
•Comes with (2) 36" test leads, three 3V lithium batteries




Don't know what you consider expensive.

 

[bruceb58]

Re: 12 volt fridge fuse?

6 Function Mini Digital Clamp Meter Item #96308 Harbor Freight. Sale: $10.29


Clamp-style multimeter lets you make instant tests and measurements without disconnecting wires. Use this clamp-on multimeter to test amperage up to 400A. The digital multimeter features an easy-to-read LCD display and an automatic zero adjust for precise and accurate measurements.
•Test AC/DC voltage, AC current, resistance, diode and audible continuity test
•Features an easy-to-read 3-1/2 digit LCD display
•Resolution: 1999
•Data hold retains information after test
•Automatic zero adjust
•Comes with (2) 36" test leads, three 3V lithium batteries




Don't know what you consider expensive.

Doesn't say DC current.

You can probably get one for $100. It won't be very accurate though but probably don't need it to be too accurate for something like this. They are pretty unreliable for the most part. A Fluke one is $300.

 

[wrench 3]

Re: 12 volt fridge fuse?

I had a similar problem when I purchased our present boat. It's a 1986, fridge is roughly the same size as yours. I went with UncleWillie's reasoning. It has a 10 gauge wire so I went with a 30 amp fuse.
BTW if the fuse is going to be in the engine compartment, make sure its a vapor proof fuse holder.

 

[UncleWillie]

Re: 12 volt fridge fuse?

The prices are coming down.
I found one for just over the $100 prediction, and 400Amps DC!

Who wudda thunk?

 

[bruceb58]

Re: 12 volt fridge fuse?

The prices are coming down.
I found one for just over the $100 prediction, and 400Amps DC!

Who wudda thunk?

And if you move them slightly, you will get 2 different readings. We have some very good ones at work and even those are a pain to use.

 

[UncleWillie]

Re: 12 volt fridge fuse?

None of this is even worth the effort to spec a one time fuse for an AC.

Take a wild guess at the current and slap in the appropriate fuse.
If it blows, pick another one 5-10 amps larger, repeat as necessary up to the rating of the wiring.
For $100 you could buy fuses by the pound and still have money left over!

 

[bruceb58]

Re: 12 volt fridge fuse?

None of this is even worth the effort to spec a one time fuse for an AC.

Yep!