ferrule crimpers for large gauge wire?

HaldorEE

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Plus you have to really compress a ferrule to make a gas tight seal. A loose ferrule is going to allow oxidation of the copper strands again resulting in increased resistance.

Here is a discussion on the issue with solder tinned wires in screw terminal. I suspect that a loosely crimped ferrule could act like a solder dipped wire.

 

SomebodyInGNV

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I have seen many examples where an uninsulated ferrule is used on large gauge stranded wire and where the only crimping that occurs is from the terminal screw itself. The result is the same as using a single-indent terminal crimping tool. Is that incorrect?

Considering the results shown in this tool vendor's video, perhaps I was using the tool I had incorrectly and expected different results?
FDT1606 - Non Insulated Terminal Crimping Tool - 16-6 AWG - Long Handl — Ferrules Direct
 

guidecca

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I bought the IWISS Cable Lug Crimping Tool, https://tinyurl.com/yymbyslg and crimped a cheap ferrule on AWG 2. It is very tight but has the dog ears on it. Will it suffice?
 

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HaldorEE

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That's not a pretty looking crimp. But if the cable doesn't come out of the ferrule and your terminal can get a good hold on the ferrule, I would call it good enough.
Bandsaw it in half and see what the copper looks like inside the crimp. If there are no voids and the copper almost looks welded, then it is a good crimp.
 

pollenface

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I make my own lugs for heavier guages using various diameters of copper pipe about an inch long pressed in the vice and then a hole drilled through it
 

MattiFin

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That is incorrect.

If the ferrule compresses further under screw pressure, then this will be similar to what happens when you solder dip wires then put them under a screw terminal. Google cold flow deformation. You don't want that to happen. It leads to loose connections over time, which results in overheated wires. If you can't properly compress a ferrule, then don't use it.
Ferrules are not same as crimp fit terminals.
Wall thickness is tiny and they don't really maintain much force/crimp on the wire.

Typical 70mm2 ferrule has something like 0.3mm wall thickness and proper crimp terminal has 1.5mm ie. 5x wall thickness.

"
The crimp connections of ferrules cannot be compared directly with connectors or cable lugs. They must be considered differently. Ferrules are used as splicing protection for class 2, 5, and 6 copper wires that are stranded, fine stranded, and extra finely stranded. The copper sleeve of the ferrule has a material thickness of just 0.15 to 0.45 mm. It is significantly thinner than that of cable lugs, for example. If the copper sleeve of a ferrule with a conductor cross section of 2.5 mm² has a material thickness of 0.3 mm, the material thickness of a comparable cable lug is 0.8 mm.

With respect to the crimping of ferrules, DIN 46228 (Part 1 - 4) describes the mechanical testing and overall dimension check starting from 2.5 mm² for class 5 copper wires according to IEC 60228. The electrical properties are evaluated in association with the later application, e.g., within a terminal block."

 

HaldorEE

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Ferrules are not same as crimp fit terminals.
Wall thickness is tiny and they don't really maintain much force/crimp on the wire.

Typical 70mm2 ferrule has something like 0.3mm wall thickness and proper crimp terminal has 1.5mm ie. 5x wall thickness.

"
The crimp connections of ferrules cannot be compared directly with connectors or cable lugs. They must be considered differently. Ferrules are used as splicing protection for class 2, 5, and 6 copper wires that are stranded, fine stranded, and extra finely stranded. The copper sleeve of the ferrule has a material thickness of just 0.15 to 0.45 mm. It is significantly thinner than that of cable lugs, for example. If the copper sleeve of a ferrule with a conductor cross section of 2.5 mm² has a material thickness of 0.3 mm, the material thickness of a comparable cable lug is 0.8 mm.

With respect to the crimping of ferrules, DIN 46228 (Part 1 - 4) describes the mechanical testing and overall dimension check starting from 2.5 mm² for class 5 copper wires according to IEC 60228. The electrical properties are evaluated in association with the later application, e.g., within a terminal block."


Thank you for the link. I find it interesting what you chose to leave out of your quote. Here is the text immediately preceding what you quoted.

"Conductor pull-out test
Crimping points can be affected by tensile forces during wiring or operation. Therefore, properly crimped connectors and ferrules must offer a high degree of mechanical safety. To test the tensile load capacity, a crimped conductor is exposed to a predefined, cross-sectional tensile force for a period of 60 seconds, and it must withstand this load. The tensile force exerts stress on the conductor at the crimping point. Damage to the crimping point must not occur. Generally, even the maximum tensile force is tolerated, until the connection is destroyed.​
Description​
Language​
Updated​
english​
03/25/2017​

Gas tightness of crimp connections​

View lengthways through the crimp
View lengthways through the crimp​
A gas-tight crimp connection is the result of a defined crimping process. The wire strands in one or more conductors and a connector are joined into a largely homogeneous structure with no gaps. This results in a permanent, reliable connection that cannot be detached.​
View crosswise through the crimp
View crosswise through the crimp​
In addition to the mechanical and electrical properties to be tested, a visual examination of the crimp area provides important information regarding the quality of the connection. To this end, micrographs or images are captured by means of computer tomography. The porosity, elongation at break, and the deformation of the individual wire strands is assessed in this way.​
When crimping is performed correctly, it is largely protected from gases such as industrial atmospheres that contain sulfur dioxide and from oxygen, salt spray or other corrosive media. This prevents gases causing corrosion on the individual wire strands during the lifetime of the connection and any resulting deterioration in the electrical properties."​


Reading this I get that the ferrule must be crimped sufficiently that it will not pull out under a predefined load (i.e. not loose). In addition it states that a gas tight seal is created by the crimping process that joins the wire and connector into a homogenous structure without voids.

I have a hard time imagining how a loose crimp could satisfy either of these conditions. I was already aware of the above requirements which is precisely why I stated what I did.
 

HaldorEE

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Here is a pic from the website you linked that shows the cross section of a properly crimped connector. I don't see a loosely crimped connection here.

pic_con_a_0078891_int.jpg
 

Gould

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The die used in the tool in post #7 (by Bob B) may be the same as I'm posting here. Same company, same purpose. I used the die to crimp ferrules on 6 gauge welding wire. I needed a square crimp, not a round/hex/whatever crimp. I already had a Pro'skit ratcheting crimper so I bought the die for it. Worked good!

Forgive the moderate hikack, would you mind posting your crimping tool?
 
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Thanks! Now to find a 4/0 lug crimper.
I have the cp-371 which can crimp 16mm(6awg), 25mm(4awg) and 35mm(2awg).
I quickly decided that for ferrules bigger than 10awg to let the mechanical lug crimp the ferrule.
I used a lot of these in my last project.
 

Gould

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Awesome, thanks. Will now spend some time debating die or dieless.
 

HRTKD

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Awesome, thanks. Will now spend some time debating die or dieless.

I had enough ratcheting crimpers that I REALLY didn't want another one in my toolbox. As I recall, there wasn't a die available for the size of ferrule that I was interested in crimping. I think it was a 1 gauge ferrule. That gauge would have required a new tool without interchangeable dies.

I settled on the Pro'sKit dies (Lunar series) because I had the Pro'sKit ratcheting tool already. Exact fit, worked well, no complaints.

I'm working on a TIG welding setup. I upgraded the ground clamp and the next step is to put in a much larger gauge of wire, perhaps 2/0. It needs a ferrule of some sort. I'll try my hydraulic lug crimper on it. If that doesn't work, I might put on a lug that has had the ring terminal part cut off.
 
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I wouldn't buy a crimper; how often are you going to need to crimp 4/0 wire?!

Here's my recommendation; posting this reference to a couple posts on the topic as this one was in beginner's corner which some people may not see:

 

Gould

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That’s a great idea, I just don’t like be constrained. I did find a local electrical wholesaler that rents them for under $10/day - will likely go that route.
 
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