DC DIN rail breaker up in smoke and now looking for replacement

[RVLiFe]

After removing all the ferrules and connecting everything together again using the bare wire, I couldn’t be happier!

Previously, I used to get a pretty big drift between what the victron SCC stated as battery voltage and what the SmartShunt said the battery voltage was. Many times my battery would sit at 13.4v at 80% battery capacity and the SCC would go into absorption mode because the SCC saw the battery voltage jump up to over 13.8 volts while charging. Now, they are both reading battery voltage within .04v of each other instead of .4v or more at times.
I would never had expected it being the ferrules and/or a bad connection causing this.
Wish I would have known about all this previously but I’m glad I got it sorted.
On another note, at least the breaker that I purchased did it’s job and terminated the connection when it detected the poor connection. At the very least it did it’s job so actually, I wouldn’t hesitate to order a new one of the same kind. I haven’t done so yet but I’m still considering all the options on a quality one and so far the Midnight ones are the favored ones.

 

[RandyP]

use of ferrules is mandated in canada and some european nations.

 

[tomy2]

So what was the verdict on the Chtaixi shut off switch? I know it is cheap, but is it junk? I am using one now, which when I tightened the wires, the plastic body split at the seam. I was going to order a new one, but probably I should go to midnite solar instead. I have a roof shut off too witch cost $80. and is not user friendly.
Also, I don't understand the ferrel thing, sems like adding another point of failure!

 

[RVLiFe]

use of ferrules is mandated in canada and some european nations.

This is why I would like to see someone actually do a high quality test on them and look at voltage drift, surface area loss, material conductivity as well as different quality of crimpers and crimps that should be done. Many opinions out there but facts are facts. Trust the science right?

 

[RVLiFe]

when I tightened the wires, the plastic body split at the seam.

Just hearing that makes me want to stay away from it. Far away.

 

[Shimmy]

Insulated ferrules make the termination a little more resistant to wear and tear from vibration in a mobile environment.
The stranded copper gets less stress as the "boot lace" connects the terminal to the wire insulation.

Isn't that more of a call for strain relief than trying to treat the terminal as a structural connection?

 

[Shimmy]

use of ferrules is mandated in canada and some european nations.

In what applications though-- I get fine-strand wire with set-screw terminals needing a ferrule (ideally a pigtail though), but struggle to understand why you would use one for a compression plate design. I also understand the logic of tinning the tip of a wire to keep the strands together, or using any number of different crimp lugs for controls.

Most terminals rely on some level of deformation to provide adequate contact area, and a ferrule makes that harder to do.

 

[tomy2]

Just hearing that makes me want to stay away from it. Far away.

Yes, I guess I answered my own question, maybe just wanted some collaboration, thanks. What did you use as a replacement?

 

[RVLiFe]

Yes, I guess I answered my own question, maybe just wanted some collaboration, thanks. What did you use as a replacement?

Haven’t bought anything yet. Temporarily hard wired to SCC with no shutoff. Still waiting for other opinions on here other than midnight solar. Has to be more than one option right? Seriously even thinking of going back to what I had. After all, it did terminate the connection and didn’t cause a fire. As a test, I set the screw as hard as I could on the defective unit and it held up great.
This breaker was also recommended by others and knowing now how it performed, I’d have no problem buying it again knowing that it was most likely my ferrule or loose connection that cause the issue.

2P 250V Low Voltage DC Miniature Circuit Breaker for Solar Panels Grid System din Rail Mount C65H-DC (32A)

https://a.co/d/iqrYOLD

 

[Tecnodave]

Correctly installing copper wires into terminals involves several retightening. I do not use ferrules on my system and have never had a connection failure......BUT.....I have found the screw terminals will be loose in less than 20 minutes due to the fact that pure copper wire does compress over time. I always go back and retighten all screw connections at least after the first hour of operation, and again after a very hot spell producing high power. Im running 40-60 amps from each combiner into each charge controller.

I cannot even remember just how many system failures that I have found in high power electrical systems, way too many to count.

Lots of years in the electrical industry has taught me to look at first inspections for loose connections in system failures.

 

[danmc]

This is slightly worrying. I'm building a combiner box ATM and have the same breakers, albeit the 63A version.

Would be interesting to see the insides of it if you ever pull it apart.

 

[RVLiFe]

This is slightly worrying. I'm building a combiner box ATM and have the same breakers, albeit the 63A version.

Would be interesting to see the insides of it if you ever pull it apart.

I truly believe it was user error (bad crimp/loose connection) and not equipment error. I’d stick with that brand of breaker personally. It did it’s job well. No need to use ferrule with a compression connection such as the ones on this breaker. Just monitor everything closely and periodically.

 

[12VoltInstalls]

twice the ferrule came off the wire and twice the ferrule came out of the connector along with the wire. I could not pull a bare wire out of the connector unless I used a vise. And even then, the wire was flattened leaving much more surface area for contact then what using a ferrule provides.

It may not be the crimper if the ferrules are thin - just saying. At least with the Epevers I’ve used, a fat bare cable has a very strong connection.
Any good crimp should probably destroy the terminal if placed in a vise and attempting to yank out the wire imho.

would never had expected it being the ferrules and/or a bad connection causing this.

I’m not being smarty pants or a jerk but I expected it. Interestingly your SCC charger having wonky readings and now not is not surprising either.
I had weird charge stuff going on a couple times and it was corrosion in the MC4s. Bad connections do bad things.

Years ago I burned out over $1000 of electronic stuff in my boat with a bad ground situation and the motor’s alternator went to 21V. Never blew a fuse because the current didn’t exceed fuse ratings but 12V electronics generally don’t want to see over 15 or 16 volts.

Good connections are everything.

 

[RVLiFe]

Good connections are everything.

That statement is true with friends, family and lovers! ???

 

[RVLiFe]

Thought I would upload a few more pictures. All the heat was concentrated at the terminal connection indicating a short and arcing at that point, resulting in the point of failure. The breaker itself looks fine. Not sure how or why the power was terminated but I’m glad that it was. Luckily the contact point failed.

 

[Mattb4]

Thanks for the pictures, but not for the increase in my anxiety level about improper connections leading to fire.

Just got done this morning wiring up manual transfer switch to critical loads sub-panel and I have to say I really dislike the low quality lug connections and cramped work space. Heavy gauge wire (10-AWG) fitted to small screw terminals is a worry. I wonder what the makers of these equipment are thinking when they do not have stout wire attachment points.

I think I will use my infrared thermometer on the new setup during initial loading to see if I get any hotspots. Followed by an occasional check to just be sure.

 

[John Frum]

I think I will use my infrared thermometer on the new setup during initial loading to see if I get any hotspots. Followed by an occasional check to just be sure.

IMO almost everyone should be doing this combined with a stress test as part of commissioning.
Then as scheduled maintenance along with checking that the fasteners are still tight.

 

[x98myers7]

watching this intently. I have the "same" knockoff disconnect/breaker... and I think I am going to actually remove it from my system since I have an upstream PV MC4 based disconnect mounted on the rack. this was for redundancy.

 

[12VoltInstalls]

Luckily the contact point failed.

Well one day I was going to take a chitaixi s apart to see what was inside. Haven’t done that. Maybe I’m dumb but is there not supposed to be an isolated pocket and divider with a magnet to extinguish an arc / spark? @Hedges @FilterGuy would you care to enlighten us please?

 

[RVLiFe]

I’d like to hear a professional opinion about this breaker and what it is lacking or what someone likes about it.