Choosing wire size

[what_barnacles]

http://www.isotherm-parts.com/PDF/manuals/cruise_buildin.pdf

 

[Ex Sailor]

Hey Guys,

I'm installing one of these freezers on the FB of our Mainship. https://www.westmarine.com/buy/isotherm--top-loaded-refrigerator-boxes--P011020542?recordNum=17

I'm trying to figure out the correct wire size, the circuit run is about 30 feet (it's closer to 25 but I'm allowing room for error). The amp draw listed is 1.8 amps, but I know the start up load is much higher than that. Any advice?

Thanks,
Doug

As was stated by others, # 14 is more than plenty for a 1.8A load and it's probably the smallest practical sized boat cable that you can buy. The start up current ( surge as many refer to ) is usually 3 -6 times the running amps but it's very very momentary in a low inertia application ie. refrig. compressor. To suggest that it should be # 10 some said # 8 etc. is a bit bizzare ... in this case. FB

 

[rwidman]

As was stated by others, # 14 is more than plenty for a 1.8A load and it's probably the smallest practical sized boat cable that you can buy. The start up current ( surge as many refer to ) is usually 3 -6 times the running amps but it's very very momentary in a low inertia application ie. refrig. compressor. To suggest that it should be # 10 some said # 8 etc. is a bit bizzare ... in this case. FB

You can buy #16 boat cable pretty easily.

That said, In my opinion, anyone who can't figure out what sized wire to use for an appliance probably shouldn't be installing electrical appliances on a boat in the first place.

As for asking the question on a boating forum, he has gotten so many conflicting answers, he is likely more confused than when he started.

Me, I would use #12 even though #14 is probably large enough. Total cost would be a dollar or two more and it takes care of any voltage drop possibilities. #12 is a good standard for boat wiring unless there's a good reason to use something different.

 

[Ex Sailor]

You can buy #16 boat cable pretty easily.

I'm sure you can Wes ! You can buy even smaller ! .... I have seen stuff on boats wired with 16 & 18 Belden.

Respectfully, I did say " smallest & practical " and by practical, I meant that it can be used for other powered stuff ... peace ... .. FB

 

[rwidman]

I mean West Marine has it in the stores. Real "boat cable". Anything smaller lacks the physical strength to be used on a boat for general wiring.


#16 would be OK for LED lighting circuits but not much else.

 

[dhays]

As was stated by others, # 14 is more than plenty for a 1.8A load and it's probably the smallest practical sized boat cable that you can buy. The start up current ( surge as many refer to ) is usually 3 -6 times the running amps but it's very very momentary in a low inertia application ie. refrig. compressor. To suggest that it should be # 10 some said # 8 etc. is a bit bizzare ... in this case. FB

Bizzare until you see that the manufacturer calls for #10 for wire runs up to 19'.

 

[what_barnacles]

Bizzare until you see that the manufacturer calls for #10 for wire runs up to 19'.

$5 says they didnt size the wire for 1.8 amps aVERAGE run current, instead the wire is sized for the worst case start current so the voltage doesnt drop.

But I digress.

If you look at the problem/action table you'll find this...

Compressor makes only short start attempts. ... Voltage shall be above 11.0 volt at start attempts.

 

[sdowney717]

$5 says they didnt size the wire for 1.8 amps aVERAGE run current, instead the wire is sized for the worst case start current so the voltage doesnt drop.

But I digress.

If you look at the problem/action table you'll find this...

Compressor makes only short start attempts. ... Voltage shall be above 11.0 volt at start attempts.

Really just go with 1 gauge, nice thick wire which will definitely work fine.