NTE Electronics R58-1A Series R58 Thermal Circuit Breaker, 250" Quick Connect Terminal, 1.35 Ohms Resistance, 1 Amp

Works exactly like it's supposed to. I had a pinball machine that was blowing fuses with a short somewhere that I had to locate. Instead of replacing fuses at $2 a piece I took a blown fuse and soldered it to the lugs of this bad boy and then pushed it into the fuse holder slot. It worked like a champ and when the fuse popped I could identify when it was blowing, and just press the reset button until I fixed the short. Works great and cheaper than replacing fuse after fuse.

In order to protect sensitive (and expensive) high powered LED modules, I employed a glass fuse that needs to be frequently replaced. Seeking a more cost effective method of addressing circuit protection, I sought circuit breakers with current ratings below 1 amp. The NTE R58 appeared to be a properly sized circuit breaker for my application. Unfortunately, the extremely slow action of the trip circuitry that makes this particular circuit breaker useless for my application and others with sensitive electronic components.There are few low current circuit breakers on the market, including this one. It is important to note that with such thermal circuit breakers, there can be a significant time delay, which is dependent on the current above rated limit. Additionally, low current breakers have a meaningful resistance that can affect over circuit design. This particular design is 1.35 ohms. (I^2*R= Power), which explains why low current thermal circuit breaker require such high resistance.From the manufacturer's literature, the circuit has to be in the 800% to 1000% overload condition to trip in less than one second. Many electronic components will be destroyed long before this. Hence, I would not recommend this product for any application that employs sensitive electronic components.From NTE Literature - time to trip based on current relative to rated amount:100% No Trip145% Trip in 1 Hour200% 10 to 45 Sec.400% 3.0 to 14.0 Sec.600% 1.4 to 7.0 Sec.800% 0.75 to 4.3 Sec.1000% 0.50 to 3.4 Sec.

I had an overcurrent that caused the breaker to trip. Unfortunately, it also let out a puff of black smoke, and now the breaker measures open. Overall, acted more like a simple fuse.