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Terminal Block, 4 to 20 Gang

$3.85$16.40

(1 customer review)

4 to 20 gang Terminal blocks

Used to interface between your switch panel and boat’s wiring harness.

Product Description

Marine Terminal Blocks


Our fully wired switch panels are meant to terminate onto one of these marine terminal blocks.  They are a handy way to break circuits out, and troubleshoot electrical issues.

We carry 4, 6, 8, 10, 12, 15 and 20 circuit,  or “gang” terminal blocks.  Each gang is isolated… so only the adjacent screw is connected.

So your switch panel ring terminals would go on one side, and the load wiring going out to your device would be landed on the other side.  This is distinctly different than a marine bus bar where all the wires and grouped together.  We also carry the bus bar which you’ll need for the negative side of the circuit.

Our terminal blocks are rated for 30A per circuit, and 600V.  They have Nickel-Plated Brass Contacts.  They use a #8 sized ring terminal.

How to choose the right size:

If purchasing to interface your New Wire Marine switch panel, you’ll need:

  • 1 gang per Single Throw switch
  • 2 gangs per Double Throw Switch
  • 1 gang for the primary input
  • 1 gang for any additional loads you’re going to jump off the same switch

Example 1:

You have 9 switches. Two are DPDT (the Nav/Anc and the Livewell/Aerator).  So you’d need 1 primary input, 2 for the Nav/Anc, and 2 for the Livewell, then 1 more for the other 7 switches.  That’s 1 +2 + 2+ 7 = 12 circuits.  So you’d need a 12 gang terminal block.

Example 2:

You have 12 switches.  One is a Nav/Anc and 4 of them are sending power to 3 night fishing lights each (12 lights total).  Do you’ll need 1 primary input, 2 for the nav/anc, 12 for the night fishing lights, then 7 for all the other switches.  That’s 1 + 2 + 12 + 7 = 22 circuits total.  So you’d need at least one 10 post and one 12 post.  Or maybe two 12 in-case you forgot something or want to add something later.

Also, you can double up on the same screw.  Makes it not quite as clean looking, but can cut down on the space needed for lots of circuits.

We’ve included a diagram below on how our marine terminal blocks are used in a typical boat’s electrical system.

Terminal Block used in a boat electrical system

1 review for Terminal Block, 4 to 20 Gang

  1. Scott Yeo (verified owner)

    Have not installed them yet, seem fine
    Your website and wiring diagrams are very helpful, what would be more helpful for me would be diagrams showing use of switches/circuit breakers and no fuses. I am not using fuses or fuse blocks.

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