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Thread: wire size to inverter

  1. #1
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    Default wire size to inverter

    I have a 85W panel with MC-4 connectors.

    What size wire do I need to connect it to the solar converter I have.

    It's a 300W solar inverter.

    tia

  2. #2
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    depends on how long the wires are.
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  3. #3
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    10' tops.

  4. #4
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    Quote Originally Posted by ant58 View Post
    10' tops.
    Let's make sure of the details. What is the panel voltage? How many panels - just one? If more than one - are they arranged in a string, or all paralleled?

    Finally, what is the Isc Short Circuit Current rating of your panel? That sets the wire size.

  5. #5
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    Quote Originally Posted by lile001 View Post
    Let's make sure of the details. What is the panel voltage? How many panels - just one? If more than one - are they arranged in a string, or all paralleled?

    Finally, what is the Isc Short Circuit Current rating of your panel? That sets the wire size.
    Using 12 now.

    1 panel, 12V

  6. #6
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    Quote Originally Posted by ant58 View Post
    Using 12 now.

    1 panel, 12V
    Well the Isc will be a little more than this, but it'll be close enough. 85 watts / 12 volts = 7 amps. The smallest NEC wire size commonly used is #12 which is good for 20 amps. So a # 12 will handle your panel nicely. #10 is the next size up, and will also work. The wire should be RHW-2/RHH (type USE-2) sunlight resistant wire. If you have an MC4 connector on the panel, just get a set of cables already made up with MC4 connectors from any good solar supplier. If your inverter has terminal inputs, get a cable twice as long as you need, with male and female connectors on either end, and cut it in half.

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