100A DC Switchable Surface Mount Circuit Breaker Link

[MEXICOWANDERER]

http://www.ebay.com/itm/Car-Stereo-Audio-Current-Circuit-Breaker-Inline-12-24-V-Protector-100AMP-100...

[Searching_Ut]

I made the mistake of trying to use a couple breakers like the one in the OP photo that I purchased off Amazon. One was rated 250 amps the other 200, both different brands. I got them instead of fuses, or quality breakers to use for my 2000 watt inverter. I'm not sure what the rating is supposed to mean, evidently some very short duration transient current flow or some sort of different Chinese electrons or something.

In trying to run my coffee pot, trimetric showing I'm pulling about 74 amps of DC current, the 250A breaker tripped in under a minute. Tried the setup again, same results. Next, after once again waiting quite awhile to let the CB cool, just for fun I fired up the microwave which pulls about 165A on the DC side. The CB tripped in a couple seconds. I then swapped in the 200A breaker which was intended for another purpose and it didn't even maintain the coffee pot load for 30 seconds. I ended up using good old fashioned cheap amazon fuses and haven't had a failure yet.

On the other hand, I have one of the inline fuse holder looking versions in line for my 600 watt inverter. It's rated at 80A and to date has never tripped on me yet, even though I have overloaded the inverter once to where it shut itself down. Of course I haven't actually tried overloading it to see if in fact it will trip.

[Naio]

I tried a couple of those car audio ones on my ice machine. Complete ****. Replaced with a bussman. And I am cheap!

[Matt_Colie]

That is the sort that I have as both over current protection and a shut off switch for my 750VA inverter for the reefer and other uses. It did open when Mary decided to use her hair drying while we were underway. I was glad it did.

Matt

[MEXICOWANDERER]

"Oooooo look for the little circuit breaker - it probably failed"

How many dozens of times have I read that on this forum...?



If you think those little breakers are the Cat's A--, well they will act exactly the same as a large circuit breaker. Proportionate heating, thermal de-rate curve, the whole ball of wax.

When a fuse is exchanged for a circuit breaker, precise protection measurement is forfeited for convenience. Don't give a **** if it's a $2.99 parts store breaker or a twenty dollar ganged Square D breaker, they are thermal animals and "precision" isn't spoken.

Larger breakers are ideal in dedicated power transmission circuits. Chassis bank feeding hotel bank and vice versa. Armageddon short. A six gauge intertie cable that passes say forty to fifty amps but protected against 100+ amps shorts. Well within the ampacity of the cable.

There are specific fuses for protecting electronic circuits and they sure are NOT ATO plastic case or SFE 14 type. They are instant reaction of precision accuracy.

Getting the drift?

Stick the linked 100-amp breaker STYLE against a standard breaker - call it fifty amperes ratings for both. Think the parts store 50 amp breaker like shown in the image above, will "outperform" the 50 amp lever breaker? Think again. The lever breaker is far more reliable.

Quicksilver's extremely expensive Klixxon switch breakers are backed up with cartridge fuses at individual point of loads. When the water pump took and end-of life dive several years ago it was not the 20 amp dedicated breaker that tripped - it was the 20-amp cartridge fuse at the pump. It worked as per design specification.

Circuit breakers and dedicated fuses - two devices for two entirely different purposes. A wiring fault can be determined in two ways. Recycle the the breaker or have a load of cartridge fuses "just in case".

I'll run one of these cheapo breakers in competition against a forty dollar Klixxon breaker and furnish the results...

[MrWizard]

that 13 amp trip comment surprises me

im glad my 40a behaves better than that

i routinely get 18 - 20 amps thru my 40a and would be p'd off if it tripped
it has not given me any trouble, or reason to doubt it
i don't have an IR gun, keep putting off buying one
it does warm up a little, but no more than the wires

[road-runner]

I use a couple of Bussman Hi-Amp breakers. They are similar but not identical to the one linked to in the first post. I'm not too happy with their trip characteristics: At 300% load they can take 10 seconds to trip, and at 200%, 40 seconds. Accuracy-wise, at 77 deg F, the trip point is between 100% and 130% of the rating, and they can take a few minutes to trip when only slightly above the trip threshold current. Before choosing a breaker it could be useful to look at the trip curve to see if it will do what you want it to do.

[landyacht318]

I have a 140 amp circuit breaker on my direct alternator to battery feed.

It popped after about 5 minutes of 65 to 90 amps then a few seconds at about 110 amps.

I am surprised it popping did not take out my alternator.

I also have a 30 amp lever type circuit breaker on my Solar which will max out at 13 amps. The breaker gets warm to the touch, registers warmer by several degrees on my UR temp gun, and drops 0.2v across it IIRC. I bet an IR thermal imaging camera would prevent people from using breakers instead of fuses on circuits where minimum resistance is desirable.

I'm never buying any budget wire protection devices again and will be removing those I currently, pun intended, and unwisely, employ.

[mike-s]

I'd trust one made for industrial purposes which at least claims standards conformity much sooner than one made for consumer use which doesn't even try to meet any standards.

[MrWizard]

i have a 40amp version from amazon on my Solar feed between panels and controller

[MEXICOWANDERER]

Look at it this way...
95% of those crappy little 2-stud breakers sold today come from Pandaland. Bi-metallic thermal technology is pretty basic. If this thing pops at 102 amps and a much more expensive breaker pops at 100 on the nose, does it matter? Those garbage can chines breakers seem to last long enough to avoid mass complaints.

The vendor is a major online auto stereo supply store. Perhaps a bit more trustworthy than buying direct from factory # 56 in Guangdong Province, China.

[GordonThree]

Blue Sea / Buss nock off? Wondering how it compares performance wise...