300 Amp Circuit Breaker with Manual Reset for Car Marine Trolling Motors Boat ATV Manual Power Protect for Audio System Fuse, 12V-48V DC (300A)

I use this for a lift gate for a truck to protect the wire and use as an on/off switch so power isn't run to the gate at all times. It can handle the 450 amp inrush when it spins up without issue.These act more as a "slo-blo" fuse rather than an instant off circuit breaker inside certain ranges. They will blow instantly but only if you go way up in amperage.First off, remember, these aren't a fuse, they are a circuit breaker and their tripping or lack there of come down to several factors, including but not limited to:1. Rated current2. Ambient temperature3. Tripping current4. Tipping time5. Tripping rangeAnd more factors than this. With a mild overload within the correct voltage range it can take an hour for these things to heat up and trip. Thus as I mentioned, the "slo-blo" type of thing. There is something called a circuit breaker trip curve and an instantaneous trip amperage. All of this factors in. When rated at 300 amp like these, they don't instantaneously trip at 301A or whatever. Why? Because what if you have an item you turn on and it pulls 450 amps like my Tommy lift for a second or two while a motor spins up. You'd be tripping it all the time and calling it a piece of crap.On higher end versions of DC Circuit breakers (Marine, Aerospace etc.) you can actually set the instantaneous trip.Look around and you might be able to find the trip curve for breakers like this and get some idea of how this one will work for you if you're worried about it.To make good use of these and build in a safety margin, up your wire size by 1 and you'll be sure not to burn anything. Your wire should always be able to handle way more than your trip setting. So if you need to pull 250 amps constant, and use a 300 amp version of these, remember they could run for an hour possibly at 300 amps before they got hot enough to trip, where as, say 500 amps, would trip it instantly.Size wire accordingly.I hope you found this helpful.

Easy!

It was easy to install and wire. Wired my winch to it for added protection against a possible short.

Fast shipping, Seems well built/sturdy. Wondering if its really going to hold 100 amps its rated for . only 1/4" in studs everything else is 5/16"

I'm a truck driver and this has already saved me.

Feels sturdy, the product page reminded people to use the button and not pull the arm out to open the circuit, I can see that as a wise operational practice (Pulling the arm out would definitely shorten the products life).I'm not the type of person who breaks something to see how durable it is, so the unit has never been purposely overloaded, however with the care and quality control in manufacturing that is evident, I believe it is the safety valve I was looking for on my system.

This is the second one that has failed. They work at first but then they heat up and deform and over time they fail in unpredictable ways.Now I have the breaker from Bussman all is good. On Amazon only the Bussman is for real (and also the one from blue sea systems) Everything else is a cheap Chinese imitation.

Purchased for use on my RV for a solar install. Had an electrician helping me, as the amperage is enough to be dangerous. He took one look at this and said that the posts didn't seem to be the correct size (I'm guessing due to required wire size for 300 amps? The stud size should be bigger?)It seems to work, and is built about how you would expect so i guess I will give it a few stars, but if it's not heavily built enough for 300 amps then I wouldn't trust it. I didn't take it apart or anything to see - he just said that the posts should be much larger to match the load. This style of circuit breaker seems to be made for lots of different amperages, but the posts don't change so I guess stick with the smaller amps? I ended up using a maxi fuse instead. It was apparent when comparing the posts and material vs this, the maxi had much more material.I'm not an electrician. Just passing on what I was told by someone with 20+ years of experience.

Good product I used the 300Amp breaker as a disconnect when storing my car. I installed the unit between the battery and + power wires.

En mi caso monté el disyuntor junto a la batería para alimentar una caja de fusibles adicional en la que de momento tengo conectados mis faros de niebla adicionales.Ha funcionado, no he tenido problemas y estoy tranquilo sabiendo que en caso de un corto tengo esta protección extra.Muy recomendable.

Perfect circuit breaker at half the price. Thank you!

Well made and work well for my application.

Great compact size with easy mounting options and very well constructed attachments. Great product.