Any thoughts on blade fuses vs auto rest or manual reset plug-in style circuit breakers?

Was looking at these: http://commerce1.cera.net/tacbuspart...asp?cat_id=432

Was thinking of putting all circuit breakers in new fuse block in stead of fuses that way would not have to worry about getting or having fuses and since I am going to mount the box above the spare tire wouldn't have to drop tire to change fuse.

???

 

I would definitely stay away from the auto-reset circuit breakers. If the circuit protection device is properly sized and blows then something needs to be looked at and probably fixed before the circuit is reset. Also in most cases a circuit breaker is not as quick to respond to a short circuit so you should be careful about replacing fuses with circuit breakers on electronic devices. In some cases before the breaker can open the circuit the electronic device is already damaged.

 

Not true. If properly designed the CB will work as well as the fuse. The big misconception is that they are many times used without proper design. CB's need to be properly designed and selected using their trip curve characteristics. Fuses in themselves also have similar but different characteristics like fast acting, slow blow as well as interrupt and surge current ratings. The CB's that "wagion" is referring to "look" to be designed specifically for automotive circuits and and are designed as such therefore will most likely work as performed.

And yes, as you said, if the circuit continues to trip you should resolve the problem. If anything, go with the manual reset breakers. Automatic reset CB's can fatigue unnoticeable circuits and are typically intended for specific circuit applications.

 

We will have to agree to disagree on this point. It is a well know fact that even the fastest circuit breakers will not react as quickly as a fast acting fuse. This is why sensitive electronic devices are protected by fast acting fuses. Circuit breakers are fine for lights, relays, solenoids, etc. but they are way too slow for electronic devices.

I've used fast acting fuses that will open on 1/4 of an AC cycle (0.004 sec) under fault conditions. If there is a circuit breaker on the market that can match this I would like to know about it.

Maybe a circuit breaker will react fast enough the for application the OP is considering. I'm only pointing out the fact that one should not simply replace one device with the other thinking that the protection level is the same.

 

I guess we could better answer you if we had an idea on what you were installing, how many and what type of loads? I would rethink the spare tire area for the fuse box, that is a major pain to service and receives lots of road debris (salt, water)

 

There is another post I made about the fuse block i used that I guess I should have just made with this one.

The fuse block is mounted inside a Pelican case (waterproof plastic box) with the wires siliconed inside and out where they pass through the box. The Pelican box is big enough that I can add relays inside it and wires as needed. 10awg wire from battery to fuse block. My plan is that this box will serve as a power supply for the rear or of the truck.
What will be hooked into it: Right now a set of 55W lights hooked into a relay and upfitter switch not hooked into back up lights.
In the future I would like to add a 12v plug in the bed of the truck, LED lights for bed of truck, LED lights for under the truck, air compressor, ... For all my lights inside the bed and under truck I plan on using LED so the power draw is as low as possible.

I figure only one maybe two of these would ever be run at same time so I am OK with a 30amp total power out of the box

Why did I mounting it under the truck above the tire? Seems like the tire semi protects that area, didn't have to drill any holes in truck, central location in back, and the two main reasons are my dogs live in the back of the truck and I don't want any live wires exposed in truck bed just in case one of them every decided to chew on them and when I haul stuff firewood, gravel, garbage, demo debris I don't want to have to worry about wires being in the way or hitting the junction box and breaking it.

I know I know PICTURES

If I can find the stupid cable for my camera I will get some posted of what I have mounted so far.

I'm not totally sold on the circuit breakers and I am a freak about my new truck so. So far I have a 30amp fuse on the wire at the battery (which started as a 40 and I replaced). Then the feed wire runs into the fuse block where all power wires will be fused or have circuit breaker. OK now comes the over kill. The only thing I have hooked into this so far is a set of small 55w back up lights from wally world that came with a wiring harness and inline fuse so I used it. (Hooked into block with 15 amp fuse for now and 15 amp inline) Which got me thinking if I put all auto reset circuit breakers in fuse block then put inline fuses in all the things I attach to it and step down the fuse 5 amp from breaker I would blow the fuse first right?

So was thinking something like.

fuse block 20 amp auto reset breaker, inline 15 amp fuse.

I don't mind the PITA this might cause me in tracking down a short as long as I don't fry the truck.

I know just enough about electricity to be dangerous

IS there a better place than the battery to hook up a + main wire?
SHOULD I add any ground cables to rear of truck?
A 10awg wire is heavy enough for a 30 amp circuit right?

 

Generally speaking the fuse will probably open first. However, it can be more complicated due to the design characteristics of each device. The fuse has what is called a time-current curve and the circuit breaker has a trip curve that will define how each device reacts to both overloads and short circuits. Which device opens first will depend on these curves and what type of circuit fault you are experiencing. I'm not quite sure what you are trying to accomplish with the auto-reset breaker and the fuse in series. Normally the only time you see two circuit protection devices in series is on sensitive electronic equipment that has a high inrush current and is very sensitive to short circuit conditions. By placing two devices in series you can use a very fast acting fuse rated at a considerably higher current to allow the normal inrush to pass without blowing the fuse but still provide very fast reaction to a short that could damage the electronics. You then install a circuit breaker or slow blow fuse rated at closer to the normal operating current to provide overload protection.

As suggested above I would probably use one of the 30A rated upfitter switches. This would allow you to easily turn on and off the feed for troubleshooting and it already has the built-in relay and fuse.

The 10 awg is probably OK for 30 amps but we can't say for sure without know what type of wire it is. The current rating for a given size of wire is dependent on both the size of the conductor (normally copper) and the type and thickness of the insulation. The conductor cross-sectional area will be the same for all 10 awg wire but the insulation can be different. How well the insulation can stand up to the heat generated by the current flow will dictate the rating of a give wire size.

 

I am a big fan of tinfoil... It has saved my but many times, cuz of those darn fuses blowin...

My opinion is, if it is a hard to get to fuse, go with the autoreset...

if it is right there? go with what ever you have. Either way, that have to be make to specs.

 

It seems like your going a little overboard. I would first use the output of the upfitters and they are fused already so your good to go. If you run out of those then build from there, I usually use a small fuse block and mount it inside the dash (ie next to oem fuse block if possible) typically the only time you see auto reset breakers are on things like power windows (reason being if someone holds a switch to long the breaker trips and resets) they do not offer the same protection as a fuse or manual breaker. If you design and wire your components properly you should have very little problems with failures.