which size wire?

[procraftmark]

I have a 89 spectrum that came with a 24lb mg, bow mount 12volt. I have an older 24volt mk 47lb thrust that I was thinking of using in there.I was going to add an extra battery and just change out the plug to work with the outlet that is in the bow now. Will the existing wiring handle it as I am not sure of the gauge wire that they used.<br /><br /><br />thnx<br />mark

 

[18rabbit]

Re: which size wire?

You need to consider the amps you’ll need for the 24v motor vs the amps used for the 12v motor. Just a guess but I suspect you will have more than enough copper in those wires for a 24vdc motor.<br /><br />Example: to move 40amps/12vdc a distance of 15ft requires AWG 6 wire.<br />Example: to move 40amps/24vdc a distance of 15ft requires AWG 10 wire.<br /><br />Here’s a wire calculator that gets posted often to this forum:<br /><br /> http://www.ancorproducts.com <br /><br />click on the [Technical Info] bottom on the top of the page for the calculator.<br /><br />Good luck!<br />

 

[Realgun]

Re: which size wire?

What 18 said. 24V requires less guage than 12V.

 

[Ralph 123]

Re: which size wire?

You need to put in the round trip distance<br /><br />

IMPORTANT! <br />Length (feet): Determined by measuring the length of the conductor from the positive (+) power source connection to the electrical device and back to the negative (-) power source connection. Note that the power source connection may be either the battery, panelboard or switchboard.<br />

the table the calculator is based on can be found here:<br /> http://www.ancorproducts.com/Technical_information/Conductor_Sizes_B.php <br /><br />There is another one here:<br /> http://www.boatus.com/boattech/casey/05.htm <br /><br />This will tell you the max amperage allowed by the ABYC regardless of length<br /> http://www.pkys.com/Reference.htm

 

[jlinder]

Re: which size wire?

I have a warning about that table - it only considers the voltage drop (as a percentage of the total voltage).<br /><br />Try asking it what you need to move 100 amps 1 foot with a 10% drop. It says you can do 100 amps with 18 AWG wire!!! (Oh my, pretty smoke)<br /><br />I would not move 40 amps with 10 guage.<br /><br />Try this for a standard. When looking for the max current through a wire I like to use the standards used on land. 14GA can carry 15 amps, 12GA can carry 20 amps, 10GA can carry 30 amps, etc.<br /><br />On the Anchor site under technical data it says you can carry more, but that is for 105 degree Centigrade wiring. I would rather not have the wires run that hot.<br /><br />Way to calculate this is remember 14AWG=15amps, and 12AWG=20amps. Then for every 4 guage size changes you double or half the current.<br /><br />For example, it you want to know what 6AWG can carry, take 14AWG=15A, then 10AWG=30A, and 6AWG=60A.<br /><br />If you need 40A, try starting at 12AWG(20A), go 4 sizes to 8AWG(40A) and you have it.<br /><br />Also, I have not checked their sites math yet. Does anyone know if the length is one way or round trip? If you have a 15 foot run you need to consider the current needs to go out and back, or 30 feet.

 

[lenny2113]

Re: which size wire?

Mark, <br />I am sorry, I do not mean to get into your post with my question, but we may both benefit from the answer.<br />Could anyone comment on what is the drawback of just going with larger wire then you really need? In other words, would an overkill hurt?<br /><br />For example, if it is required per calculations to use 4AWG wire for battery cables, go with 2AWG wire. I only see cost of wire as a real drawback.<br />I may be wrong.

 

[18rabbit]

Re: which size wire?

Originally posted by Lenny2113:<br />Could anyone comment on what is the drawback of just going with larger wire then you really need? In other words, would an overkill hurt?

The biggest hit is to the pocketbook. Larger wire costs more, other than that, no problem. More copper means less resistance, less heat, and less voltage drop. In the words of a paroled Martha, “…and that’s a good thing.”<br /><br />Since Mark already has wiring in place for a 12vdc tm, it is almost for sure he has more copper than needed for a 24vdc tm. The only way he wouldn’t is if the 24v motor is significantly (over twice) bigger than the 12v motor.

 

[procraftmark]

Re: which size wire?

thnx guys<br /><br /><br />mark