Identify the amperage of a breaker

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Seevee

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Sep 1, 2016
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usa
Vessel Make
430 Mainship
Is there a way to identify the amperage of a circuit breaker using a meter or something?

I've got an AIRPAX with no part number and no lable for amp rating. Came off the flybridge of my Mainship 430.
 

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It looks more like a toggle switch than a breaker. If you know what it's powering, I would take that and add 20% or what they would suggest.

If its off your flybridge, I would look all the wiring over. This year I need to go though the wiring on mine. You can see its aging looking at the switches and connectors.
 
Look at the wiring. If it the same gauge in and out, then it almost certainly is a switch which I agree with Iggy, is what it looks like.

David
 
No way to tell unless labeled. Google Airpax and you will see images of similar breakers. Is it AC? What is the wire size on the load side?
 
According to patent #3251232 (embossed on the side) it is indeed a breaker. It looks like there used to be a label on the side. I don’t know of any way to measure anything on a breaker to determine it’s rating.

Ken
 
Uh, isn't the breaker size based on the supply wire size? of course, if this is the second breaker in series, it's size might be smaller than the primary breaker and sized to protect the load it switches.
 
You often see a switch downstream of a breaker. You rarely if ever see a breaker downstream of another breaker unless it is part of a power distribution panel.

I still think that this is a switch, not a breaker. It doesn't look like a breaker.

David
 
It is what is called a bat handled circuit breaker. I don’t think there is any easy way to test it’s rating. Just buy a new one.
 
Breaker testing is done all of the time and requires specialized equipment to do it. Contact a breaker testing company or base the replacement on wire size and connected load. Use a clamp on amp meter to determine the actual load and size accordingly.
 
I too thought it was a switch. Never seen a breaker like this, but there it is.


To test it you would need a power supply with current limiting. Run 10A through it and see if it pops. Then try 15A, 20A, etc. But who has that lying around?


I agree that your best bet is to sort out what you need by other means. First, figure out what wire gauge is on the load side. That will tell you the max rating. Then also look at what it powers to decide if it should be lower than the max.
 
So, we have decided it is a switch, well ok. The simplest way to deal with it and be safe is to check the wire gauge out, assuming it is the same or smaller than the wire gauge in. If otherwise, then I give up :blush:

Then replace this "breaker" with one appropriate for the wire size, ie 20A for 12 gauge, 15A for 14 gauge, etc. Make sure the device it powers at the other end doesn't need a smaller breaker to protect the device. That would be unusual.

David
 
I just looked online and Airpax does make circuit breakers that look like that.
 
So, we have decided it is a switch, well ok. The simplest way to deal with it and be safe is to check the wire gauge out, assuming it is the same or smaller than the wire gauge in. If otherwise, then I give up :blush:

Then replace this "breaker" with one appropriate for the wire size, ie 20A for 12 gauge, 15A for 14 gauge, etc. Make sure the device it powers at the other end doesn't need a smaller breaker to protect the device. That would be unusual.

David




No, I think we concluded that it's actually a breaker. Checkout the DigiKey link. I've never seen anything like it before, but there it is.
 
I just sold a boat that had very similar breakers. Mine had an amp rating stamped into the slightly flattened and of the toggle.
 
No, I think we concluded that it's actually a breaker. Checkout the DigiKey link. I've never seen anything like it before, but there it is.

Sorry, I misspoke. I meant breaker not switch. I need to reread my posts more carefully in my dottering years :blush:

David
 
Last edited:
I read mine several times and still make mistakes. I read them again after I submit them and sometimes go back several hours later and find mistakes. The good thing about being a moderator is that I can edit them at ant time later and fix my mistakes.
 
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