Circuit breakers - backwards

bassin_louisiana

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Sep 17, 2017
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All, I installed my circuit breakers backwards. I put the cable on the battery side and connected the aux side to the bracket going to the battery terminal. Does it matter if they are backwards or will the breaker still work? Trolling motor works fine so current is running through. Please advise.
 

sam am I

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It'll still work and be just safe, circuit protection wise.......The design internally however, when the thermal breaker opens, is designed to have minimized the still live components (the "line" contact and its' buss bar leading in) within the breaker housing to just a small area (see below), thus when opened, 95% of the internal guts go dead/off. You'll just have more hot guts if/when it opens is all.

Click image for larger version  Name:	thermal-magnetic-circuit-breaker-trip-latch-operation.JPG Views:	1 Size:	19.7 KB ID:	10736152
 
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bassin_louisiana

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Thanks, Sam am I!! After I wrote this, I called every marine shop in town and they all said this would still work just fine but your explanation is more helpful in terms of the components. My next question: id the break DOES trip, will I be able to reset it if the guts are gone? Or, will I have to replace the breaker on the water?
 

sam am I

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My next question: id the break DOES trip, will I be able to reset it if the guts are gone? Or, will I have to replace the breaker on the water?

Correction to the above "be just as safe" not "be just safe"

The guts aren't gone per-se, the major parts of the guts will just remain energized when the breaker opens as where if it were hooked up "properly", the major percent of the guts would be non-energized.......It's all good, you'll be fine.

And no, you won't be replacing it at all, anytime.......After the bi-metal cools(the breaker opened the circuit), it will automatically reset internally just like normal, you'll just have to manually flip the lever again like always, you or it will be none the wiser.
 
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gm280

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If it helps, current in any circuit is the same at any point in the circuit (for the sake of this conversation anyway). In other words, if you break the current flow at either the positive input or negative ground, the circuit is dead. Usually people install the breaker before any circuits. But any place in the current flow line will render the circuit dead when the breaker pops.

However, I have to ask, why did you install the breakers in that fashion? Did someone tell you how to do them, or is this your idea? Not saying it is wrong or worrisome, just not typical usual breaker installation setup! Usually you have a wire from the positive terminal of the battery going to the line side of the circuit breaker. And the load side of the breaker going to the circuit. Just wondering...
 

bassin_louisiana

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Thanks, gm280. Honestly, I installed them exactly as the old ones were...backwards. I had no instructions—I just replicated exactly how they were wired. Here are some pics after install (not much to see but the breaker should be rotated 180).
 

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sam am I

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Not that it really matters at this point, as we've just discussed/determined but, seems all to easy just to flip'um round if'n ya care too? I mean, it wouldn't personally be keepn me up at night, however some here would be hav'n night sweats....


ALSO.....Those appear to just be thermal/bi-metal breakers, not thermal magnetic(my mistake, sry)which makes the internals a bit simpler and as such, the reversal is even more a moot point.
 
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bassin_louisiana

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Sep 17, 2017
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I can flip them but these breakers break very easily and I wrenched them down pretty tightly. It would take 5 minutes to reverse them but I broke both previously installed breakers taking them off. The plastic is incredibly cheap and the screw started to spin. I had to tear the whole thing apart (both of the old ones!), then put vice grips on the screw to get the washer off....if that makes sense. That’s my whole reason for not wanting to mess with them if they will were as installed. Sounds like I’m OK. Thanks so much for the input guys!
 

gm280

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Don't worry, be happy... Happy boating and forget all about this now!
 

KD4UPL

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Just a few observations:
Cheap parts are never a good idea. Every connection has a recommended tightening torque. For a lot of things, particularly electrical terminals, it's not really as tight as you might thing. These aren't lug nuts, snug is fine.
I agree, it probably doesn't matter with those breakers. I'm the kind of guy who would flip them around.
 
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