Fuses vs Circuit Breakers

[howson]

Why are the AC circuits in our trailers connected to circuit breakers and the DC circuits to fuses? Why not just use circuit breakers for everything?

[Cate&Rob]

Why are the AC circuits in our trailers connected to circuit breakers and the DC circuits to fuses? Why not just use circuit breakers for everything?

I expect that this is just a "cost" consideration. Fuses are much less expensive than circuit breakers and provide the same level of protection. Most circuits will live their entire life without ever blowing the fuse.
You can plug a circuit breaker into any fuse holder. Such as https://www.amazon.com/Tocas-Manual-...86RX2WMHH49BND

Rob

[howson]

I expect that this is just a "cost" consideration. Fuses are much less expensive than circuit breakers and provide the same level of protection. Most circuits will live their entire life without ever blowing the fuse.
You can plug a circuit breaker into any fuse holder. Such as https://www.amazon.com/Tocas-Manual-...86RX2WMHH49BND

Rob

Wow! I didn't know those mini-circuit breakers existed. Thanks for the post, Rob.

[Guest]

Here is a breaker I purchased to replace the cheap unprotected breaker at the front of the trailer next to the junction box on the frame. I'm also purchasing one for the tongue jack. These are resettable and waterproof.

https://www.amazon.com/Tocas-Surface..._dp&th=1&psc=1

[howson]

Here is a breaker I purchased to replace the cheap unprotected breaker at the front of the trailer next to the junction box on the frame. I'm also purchasing one for the tongue jack. These are resettable and waterproof.

https://www.amazon.com/Tocas-Surface..._dp&th=1&psc=1

Exactly what I'm using in my DC-DC Charger project (except it's the 60A version).

[Guest]

Howard,

The resettable breaker can also be used to intentionally open the circuit to the front jack as a method of theft prevention if mounted inside the passthrough. I'm not sure how many rigs are stolen and towed away but thinking it wouldn't hurt.

Jim

[Country Campers]

Thanks guys , more money well spent.

Brian

[steve&renee]

...the cheap unprotected breaker at the front of the trailer next to the junction box on the frame...

I'm confused. What does this breaker control, and why do you say it's unprotected? I don't know what it means to protect a breaker.

-Steve

[Yoda]

Many Many Many years ago in electronics class we tested circuit breakers against various fuses and measured reaction time and overload time required. At that time the fuses reacted faster, maybe a few milla seconds. Instructor indicated that for the electronics the fuse protected that would be an eternity. Not sure if it is still true today, but for the price of the circuit breakers shown you can buy a heck of a lot of fuses. When I wired in my CPAP circuits I use a new type of fuse that lights up when blown. The actual fuse light up.

[howson]

I'm confused. What does this breaker control, and why do you say it's unprotected? I don't know what it means to protect a breaker.

-Steve

I suspect Guest 's (Jim) comment regarding "unprotected" means "open to the environment". These breakers are behind the front of the "A" frame, street side.


These breakers protect the camper from the incoming current from the battery, and (for my camper) the stabilizers, front tongue jack, and emergency brake actuator.

The diagram below should give you an idea (hopefully!). Note this circuit is specific to my modified electrical setup.

[Guest]

I'm confused. What does this breaker control, and why do you say it's unprotected? I don't know what it means to protect a breaker.

-Steve

Steve,

My comment on the breaker is based on being unprotected from the environment, moisture, corrosion, etc. On my Imagine, there is a single breaker that protects the main 12V circuit on the camper. My tongue jack is protected by an inline fuse currently.

Jim

[Cate&Rob]

I'm confused. What does this breaker control, and why do you say it's unprotected? I don't know what it means to protect a breaker.

-Steve

Hi Steve,

The breakers that these guys are talking about are "marine" quality. This means water proof (weather protected) and not a spark source (ignition protected). For this application, the weather (water) protection is probably the most significant. This circuit breaker is close to the propane tanks, but in an open environment, so ignition risk is probably slight. Marine parts are built to standards far beyond anything OEM RV. Anytime that you can use a marine part in an RV, you are well above the RVIA "requirements".

Rob