Breaker plus Fuse (charging side)

[Vern]

I'm about ready to connect all the components for the cargo trailer solar install and plan on an ANL fuse (60a) as close to the battery as possible and a Blue Seas surface mount breaker (50a) next to the charge controller. The question is... is there a possible downside to this redundancy? The wire run is short, 5-6 feet and the #6 wire should be OK for the 45w max of the controller. Am I missing something important? I sure as hell don't want to burn down all my hard work or put too much resistance into the charging side of the system.

Thanks in advance!

Vern

 

[SternWake]

You have to have a fuse next to battery, and the charge controller calls for its own fuse/breaker

The problem with circuit breakers is they are activated by heating. When well below their tripping threshold, they are still making heat.

I have an inexpensive 30 amp circuit breaker inbetween my chargecontroller and battery. i can measure voltage drop across it and it does get warmer than surrounding wiring area even passing 10 amps. I like the push button connect lever reconnect, but I would prefer a fuse instead. partly as I do not trust the breaker to trip at its rating anyway duw to experience with another inexpensive breaker tripping well below its rating.

My 140 amp breaker tripped after a few minutes of 60 to 90 amps then tripped at ~110 amps and could have taken out the diodes in my alternator.

I highly regret my economical wire protection purchases. Since I consider them all suspect and have to replace them with something I can respect and trust, the money 'saved' was ultimately money wasted.

 

[Wabbit]

Nothing informed to contribute, however, I put a 100a fuse going into the battery and a 100a fuse coming out. Not sure if overkill, but it looks kinda cool..

 

[John61CT]

Every device and connection drops voltage and is a point of failure; only put in what you really need.

 

[Trebor English]

When comparing breakers and fuses, fuses come out ahead.  Breakers are much more likely to fail to trip.  Breakers are more likely to trip at a lower current due to heat and vibration.  Breakers are more expensive.  Breakers have more resistance.  Fuses come in fast and slow blow flavors, breakers are only extra slow.  People think breakers can be used like switches and wear them out using them as swtches.  

Breakers are better if you can't trust the human to replace a blown fuse with the correct size and if the cost of replacement fuses is high due to frequent failure.  If the circuit is overloaded it would be better, safer, to correct the problem.  Circuit wiring can be insulated and supported so that failures are avoided.  Then fuses blow very rarely and those breaker advantages diminish.

Why would you want breakers when you could have fuses?