Wire size for 18v 42w led light?

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Old 09-10-19, 09:25 AM
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Wire size for 18v 42w led light?

I need a recommendation for a wire size for this overhead led light i want to repair.

The light consists of 4 18v led strips wired in series and originally ran on 72v. Two of each strip are soldered directly together while their is a 24awg wire connecting the two sets of two.

I wish to disconnect them and wire them in parallel so they will run off 18v and roughly 2.5 amps and am not entirely sure if the 24awg wire used originally will be good enough or if a larger diameter wire is required.

I assume that given the 24awg wire is being used for the original connection it should suffice for the parallel connections however i'm not entirely sure and don't want to risk it without atleast some confirmation.


**IN SHORT**
Would 24awg wire be sufficient to connect 4 18v led strips in parallel with a total current draw of approx. 2.5 amps?
 
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Old 09-10-19, 11:04 AM
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What is the distance from the lights to the 18 volt power source?
 
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Old 09-10-19, 11:09 AM
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The 24awg wire isn't going to be the wire running to the power source, only to connect the led strips together in parallel. The length of the connecting wire will be only a few inches a piece. I currently have 2 18v power sources I may use, one with 18awg wire and one with 16awg, both have barrel jack connectors and will connect to the led strip wires via a connector.
 
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Old 09-10-19, 11:14 AM
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The #24 may have a problem even running the lights in parallel. That's some pretty thin wire.
 
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Old 09-10-19, 11:59 AM
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I figured so as well, though i wasn't sure since it was being used in the original circuit which ran off 72v and approx. 0.6 amps for 42watts, However i'm not entirely sure how much a difference it would make the way I want to set it up.

Here are 2 diagrams of the original layout and my planned layout. So you can see easier how it was and what I plan to do.

As a note I don't have any issue using a larger size wire i'm just unsure what the appropriate size would be for the voltage and current it will use is.
 
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Old 09-10-19, 12:47 PM
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No good. You're showing running 2.5A thru #24 wire at 18v.

When the lights were in a series loop and running at 72v..... the voltage drop was manageable due to the circuit voltage.
 
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Old 09-10-19, 12:49 PM
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What would be a suitable wire size for this then? I have a fair collection of various sizes and don't mind using a larger wire but am just unsure what would be suitable for this.
 
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Old 09-10-19, 01:46 PM
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Try at least #18 like the power supply uses.
The larger the better as it can never be too large.
 
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Old 09-10-19, 01:48 PM
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Alright thank you very much =)
 
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Old 09-11-19, 06:11 AM
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The distance (length of the wires) is very important to come up with the proper calculations.

If I had to pick a number out of thin air I would have suggested #12 gauge.
 
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Old 09-11-19, 07:53 AM
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The length of the wires will be around 2-4 feet in total for both the positive and negative, to be honest 12 gauge seems fairly large to me as thats often used for mains wiring and this shouldn't be using nearly as much power as that.
 
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