question

stevewhale avatar image
stevewhale asked

Can I use a 40amp mega fuse at lynx distributor for smart solar mppt 75/15

Hello, I'm connecting a smart solar mppt 75/15 to a lynx distributor, which utilizes mega fuses and then to the battery bank. The maximum battery fuse rating for the MPPT charger per the manual is 25A and the minimum is 20A. The smallest mega fuse I could find was a 40A for the Lynx distributor. The MPPT charger has a 20A fuse already installed, but the manual says that another fuse is required even if the solar charger has been equipped with an external fuse.

  1. Do I need to keep searching for a 20-25A mega fuse or will the 40A be sufficient?
  2. If I can't use the 40A mega fuse and can't find a 20-25A mega fuse, should I just run my MPPT battery connections through by blue sea fuse block with the correct fuse size? I have plenty of room, but it just doesn't seem like a conventional method running to the fuse block, through the lynx, and then to the battery.
MPPT Controllers
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2 Answers
Sarah avatar image
Sarah answered ·

The fuse is there primarily to protect the cabling. As long as the cables can carry 40 amps you should be right.

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kevgermany answered ·

If the fuse is between the controller and batteries, not good. If it blows, you'll have a charge controller with no battery, but panels connected. Can break the controller. Better to fuse on the panel side of the controller.

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klim8skeptic avatar image klim8skeptic ♦ commented ·

How is this different to the fuse in the mppt going open?

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kevgermany avatar image kevgermany ♦♦ klim8skeptic ♦ commented ·
Might save a dealer visit to fix.
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