I have pulled several to pieces from several different products not just victron.
The box clamp can only move upwards parrallel as it runs in a guide. The top of the clamp is fixed. It leverages against the top (the box i am sure you saw moves upwards.).
The fitting is quite deep. The ones attached are the ones from a 250/100.
Yeah, right, bit of confusion with upper / lower.
I was refering to the part that is “further away” from the screw - so would most likely be referenced as lower. That one has a bit of freedom to move.
But when looking at it in detail, there are two narrows (which obviously help to hold on the cable / ferule) - eventually the ferule just reached the second one and hence it appears that it is closing anti-parallel, even if the “higher squeeze factor at the tip” is just a result of lesser space at that position:
(Excuse my highly professional paint-skills, hope one can guess the idea)
With the short ferrule, it may even just reach the “first hook”, which makes this appear even worse.
The two ‘pips’ there are locating points for the fixed clamps (ones that are soldered to the PCB). So they not for gripping the ferrule/strands at all.
When the box rises (one of the previous picture i posted) they ride and have notches in those positions as they line up.
The ferrule in your artful picture should be much longer and go passed that point anyway.
I remember that I’ve seen a study on ferrules vs. non-ferrules for fine-stranded wires in cage connections. It came to the following conclusions:
Unfortunately I can’t remember where I’ve seen this information…
There is no right or wrong answer here you use whatever gives you the maxim contact area for where and what you are connecting to/from (this is the most important thing), mostly a lug will give maximum contact but if not applicable then what fits best, sometimes that will be a fine stranded wire of correct specifications (sometimes referred to as welding cable) sometimes it will be a ferrule, some of the BS Standards
I work to are BS7609, BS7727 & BS7671.
The other point i always try to impress is keep POF (Point of Failure) to a minimum, so as few connections as safely and legally possible, every time you add a connection you increase the risk of creating POF and even SPOF (Single Point of Failure) that will stop you system from working.
I have wired/install/designed lots of high current equipment over the years upto 100Kva AC & DC so I know what I would use in these types of appreciations, but its your call.
But always follow the manufacturer instructions and recommendations.
Good luck.
Dave.
Very interesting discussion, thank you all for the input!
I’m in the middle of what will be a years long house renovation and installing solar in it.
All these concepts are being formed/refreshed in my mind, since school was 30 years ago, and I really haven’t worked on the electric field.
I finished my home’s electric board a pair weeks ago, placed the 3 phase 5kva multis and the 450/200 RS MPPT on the wall and started wiring some of them. Naturally, ferrules are in the multi strand wires of the installation.
Now, something I found a bit strange is a certain type of ferrule, that I saw here for the first time.
My energy supplier has these in all the wires. I found it named in several places as Pin ferrule.
What is your take on them? My first feeling is that because they are thinner than the wire, they carry less current than the wire. Am I wrong?
Example of them
The wires of the energy supllier coming in the EM24
Personally I feel I like this type better, but on the other hand they seem less safe.
What’s your take on this?
Thank you again
Nuno
This poses a bit of a problem for our installs as our local electrical codes require ferules on finely stranded cable for mechanical strength. The section that it is mentioned in is vague enough that you might be able to argue that in this case it can be ignored but it would mean arguing with inspectors.
Hi Everyone,
I have recently updated the ferule chapter in the Wiring Unlimited book, see the Electrical Connection chapter.
I know that ferrules remain a topic of discussion, and many people have their own vision on them. The main rule is to ALWAYS use a correct crimping tool to achieve a “gas tight” crimp and the electrical terminal needs to be suitable for ferrule use. Actually, many terminals are suitable for ferrules, more than you might think. To check consult the terminal manufacturer’s specification sheet. And then (of course) always follow the Victron manuals in regards of ferule use and apply the correct torque when tightening the terminal.
The manual for my 100/30 MPPT controller specifies the multistrand wire but doesn’t say to use or not use a ferrule. I used ferrules but I was told that was a mistake. When I read the book you amended, it seems ferrules are “allowed”. I think if the MPPT controllers have a unique need for bare wire, shouldn’t it say so? Thanks
Referring you here…
They don’t have a unique need. Their design is that you don’t have to use ferrules with the rising clamp.
The ferrules are not outlawed either.
It is just most ferrules when done are not done right. Then the rising clamps are not torqued right either. And then there are issues.
Even bare wire install we have seen wire clamped on insulation, wires not stripped back far enough (go full depth in the clamp) just to name two common ones.
When installing the advice is simple- be sure you are doing it right.
There is a popular YouTuber by the name of the Explorist if I remember right. He has a video specific to ferrules. In the video he has a section showing a Victron employee encoraging the use of ferrules in all applications. He states he was told by Victron to always use ferrules. I think the advice was circa 2019. Was subsequently told that it is no longer the stance of Victron specific to MPPT controllers. My point is, there is conflicting advice from Victron. In this gauge, 6, it is easy to crimp on a 4-sided ferrule.
‘Official statement’ is really in the wiring unlimited. And above reply
I know the use of ferrules is often encouraged in new installers as it prevents fly aways and clamping on insulation. Their correct use does have advantages.
Many which have been discussed in the long thread here.
I totally agree, and I could have not worded it better myself 
