Question:Resettable Circuit Breaker Mounting Orientation

[featherliteCT1]

I want to use these kind of resettable circuit breakers to protect some wires in my solar system.

200904 Blue Sea 40 amp Breaker.jpg (26.32 KiB) Viewed 1528 times

Assume a 12V system with all copper wires.

Are there any restrictions concerning how to orient the the circuit breaker when mounting the unit?

Example 1, can the circuit breaker be mounted on a vertical wall with the yellow reset lever oriented towards the ceiling, so that the written words “Thermal Circuit Breaker” scribed on the breaker appear upside down?

Example 2, can the circuit breaker be mounted under a horizontal surface, like under a wall shelf, so that the written words “Thermal Circuit Breaker” scribed on the breaker face the floor?

I have submitted this question to two different manufactures and am hoping to hear back from them; however, that might be never or a long time from now.

Thank you for your help,

[tony.latham]

Any orientation will be fine. The magic pixies running through the wires will never know.



Tony

[featherliteCT1]

Thanks Tony,

I would think that you are correct.

However, one of the manufacturer's spec sheets said "do not mount upside down", with no explanation why. It seems to me that "upside down" is an ambiguous term. That is why I gave two different examples of "upside down".

I am hoping others can confirm that we are both correct.

[saltydawg]

just looking the pic it seems because of the water proof writing. if "upside down" water could get in the mechanism due to the reset lever coming out of the bottom. But right side up water does not run up hill

[featherliteCT1]

saltydawg,

Good eye!

[featherliteCT1]

The question I submitted to Blue Sea Systems did not ask about the polarity of the subject circuit breaker, because, at the base of the “top” stud of the breaker, the term “Bat” appears in raised letters, and at the base of the “bottom” stud, the term “Load”” appears in raised letters (although a Eaton-Cooper Bussmann breaker I have reads “Aux” (which Aux means the same as Load). My assumption was that, clearly, the battery needed to be connected to the “Batt” side of the breaker.

Below is Blue Sea Systems’ reply to my question about the required mounting orientation of the breaker:

“Thank you for the question. No need to flip the breaker over. The breaker will work with the battery attached to either post.
Please ask if you have any additional questions.
Best Regards,

Blue Sea Systems Tech Support”.

Given that I consider Blue Sea Systems to be a very credible source, without surprise, I assume that orientation makes no difference and, surprisingly to me, it makes no difference which post the battery is attached to.

Note that Blue Sea Systems' answer did not expressly say that orientation does not matter; rather they said " No need to flip the breaker over". I am assuming that actually flipping the breaker over would not be a problem.

As an aside, my further research discloses that a different kind of breaker works using some other kind of technology where orientation is critical, and another kind of breaker that will catch fire if wired backwards (I saw videos of burning breakers on Youtube).

Edit: I followed up with a second orientation question about whether I can I flip the breaker over i.e., orient the breaker up, down, sideways or upside down?

Below is the reply:

“If the breaker is installed in dry area, that will work. It is not recommended if it is in a wet area.
Please ask if you have any additional questions.
Best Regards,

Blue Sea Systems Tech Support
”

[MtnDon]

Yes, some breakers are clearly marked with "top", "up" or whatever. Those must be followed. As well some must have the correct terminal connected to line or load. Some of those rely on having input voltage present at the input side in order to function. That is common in residential and commercial AC wiring with AFCI and GFCI breaker types. I would think that if the breaker is not marked it probably does not matter and that if a breaker is marked it might very well be important.

In AC wiring one other reason for "up" markings is to ensure that ON is always UP and DOWN is always DISCONNECT. That can save time and be safer when emergency crews need to turn off a circuit. The NEC states that when breakers are installed vertically, UP must be ON.

[featherliteCT1]

Mtndon,

Does it concern you that the Blue Sea circuit breaker terminals are marked bat vs load side, but the Blue Sea tech in effect said that it does not matter which terminal the battery is connected to?

[saltydawg]

“If the breaker is installed in dry area, that will work. It is not recommended if it is in a wet area.
Please ask if you have any additional questions.
Best Regards,

Blue Sea Systems Tech Support
”

Ouch my shoulder, I just hurt my shoulder trying to pat my self on my back.

JK it seemed like common sense to this master electrician

[saltydawg]

Mtndon,

Does it concern you that the Blue Sea circuit breaker terminals are marked bat vs load side, but the Blue Sea tech in effect said that it does not matter which terminal the battery is connected to?

No they are just marking it for the idiots who would call them up if they did not mark it. I consider that idiot proofing, even if it does not matter.

[MtnDon]

Or the tech person at BlueSea is not as good as their products are....

[Squigie]

Keep dust and debris in mind as well. (I didn't see it mentioned above. I may have missed it.)
It doesn't sound like you're considering such, but I wanted to make sure it was mentioned.

If mounted on the floor of a compartment, or with the lever exposed to settling dust (upside down on a wall/bulkhead), the dust and/or debris could become an issue.

I had that problem with a resetable circuit breaker mounted to the floor of the electronics bay in my first pop-up tent trailer. Eventually replaced it with an auto-reset breaker, since I didn't want to rewire in order to relocate.

[featherliteCT1]

I really appreciate all the good comments.
So, just like the writings on the circuit breaker that state "bat" and "load" mean nothing, so "waterproof" means ...?

I already mounted and wired my breakers "upside down" so as to keep the battery wires on the "Bat" side". The breakers are mounted on an inside wall of my trailer, above the battery, but below my loads. I did not want to route the "bat" wire above the breaker and then curl the wire back down towards the Bat terminal on the breaker. Nor did I want to route the "load" wire below the breaker and then curl the wire back up towards the load terminal on the breaker.

I am happy to know that the orientation of my breakers is ok.

In the course of my research, I noted that Blue Sea advertises the specs with graphs for their different breakers respecting time delay and maximum amp thresholds before the breaker releases. As things now stand, I do not know what time and amp thresholds I should be looking for. In due course I will go back and see if my breakers are correct. They are relatively expensive and I would hate to have to replace them.

[featherliteCT1]

Today, as I was researching DC circuit breakers again, I stumbled across this article that says that the DC Blue Seas breakers must be wired with proper "polarity", contrary to my previous conclusion.

"Reversing polarity would result in safety issues and irreversible damage."

"Direct currents flow has one and one only ‘unidirectional’ flow of electrical charge one [sic] a constant direction, e.g. batteries or solar cells so the DC circuit breaker must respect that one direction charge."


https://marinesupplydock.wordpress.com/ ... kers-acdc/

[sic] In the quote, I think that the term "one" should read "in" … a constant direction. Meaning, current flows in one direction.

[MickinOz]

I have used a similar circuit breaker in the solar panel supply line to my charge controller.
I connected the +ve of the panel to the "Bat" post, and the cable to the charge controller to the "load" posts.
However, I struggled to mount it "up" as the heavy wiring was difficult to bend.
So I mounted it sideways. I don't expect any issues, but I will point out one consideration I had.
I wouldn't put it upside down, i.e. oriented so that the yellow lever is on the high side.
Very unlikely, but you wouldn't want gravity trying to reset the breaker when you aren't ready.