Ferrule crimping for power connection to PCM/VRM


We’re having trouble with our power Weidmueller connections to the PCM and VRM. The 18-20 gauge wire is too large for the ferrules that will fit into the connections. Could be some operator error here.
Researching this, we are confused on the shape of the crimp. THere are multiple ferrule crimper shapes (square, hexagonal, flat, c-shaped). We have a square model. The one sold from Weidmueller is hexagonal. Some crimpers leave ridges and some don’t. Ridges seem like a good idea to help secure it.
The POE cable has a nice ferrule crimped on it but we are not sure how it was done or where to get them.
Is there a best practice on this? Best shape of crimper? Ridged crimping versus smooth? Source of the correct size ferrules?
Thank you


We bought this kit in 2017 and have loved it. It forms the crimps to the right shape for the connectors on the kit electronics.


It appears to make c-shaped crimps. Is that correct? Also, are the ridged? Are you able to get 18 gauge wire into the VRM power connector?



Weidmueller makes really nice tools, but you pay dearly for having Weidmuller stamped on the tool. Cross the Road sells a nice ferrule crimper. and ferulles. Automation Direct also sells ferrules and ferrule crimpers. You want to be sure that the ferrule is a tight fit to the wire before crimping. Regardless of the wire size on the ferrule bag and on the wire. I have never had any luck getting a 16 gauge wire size ferrule in the PCM connectors.

PS: You (I) often have to push in the clamp release while inserting the ferrule rather than just pushing the ferrule into the connector with releasing it.


Ish… they’re like the PZ 6 Roto in @pugsly14’s post above.

Yes. I don’t know of a non-rigid crimp though… No.
Fixed, thanks @FrankJ


I get real nervous with ‘one size fits all’ self-adjusting crimpers like these. When I have sectioned crimps made by this style in the past they are not fully welded shut. 4-Die crimps like that are not the same shape as the weidmuller socket, so the contact is not as good as the proper crimp shape. I’m sure that they are better than nothing, but they are not optimal.


I believe he meant ridged as in serrated. Depending on the shape of the crimping die, some crimpers make smooth crimps. The PZ 6/5 is an example.


I have one like Cross the Road sells, and in the video they show crimping it, turning it 90 deg then crimping it again in order to fit it into the PCM module.



That ain’t right.


What is the shape of the socket on the VRM? We’re trying to figure out what shape is best and cannot tell by looking at it.
CTRE, the VRM maker, seems to recommend a square shape since that’s the crimper they sell. But they don’t say it anywhere.


Our team just started using Ferrules as a standard this year, per my suggestion. We use the crimp tool sold by CRTE, which use a square crimp style. This crimp tool works great for the Weildmuller connections on the VRM and PDP.


I can’t tell you off of the top of my head with 100% certainty.


@FredK here’s a demo of the Weidmuller kit that I linked above.


For ferrules, I perfer buying them from sites such as Aliexpress. If your willing to wait, the prices are much cheaper(Example). You do have to be careful through and read the descriptions. You want a length of at least 10mm or else the weidmuller will not grab the ferrule securely. As for colors, Jersey Voltage likes to buy the colors that match the wire color. However other teams buy the colors that correlate to a size. Such as, green for 12awg, red for 18awg, etc. The color is not standardized, thus “orange ferrule” from one website probably won’t be the same size as the orange ferrules from CTRE.


The ferrules can be pulled out of the connection. Crimped 18 gauge ferrules on the 18 gauge wire and could not pull them off. Serrated square pattern. Barely got into pcm and vrm but buried it to the insulation. Unlike bare wire, I was able to pull them out.
Can y’all confirm your 18 gauge ferrules are passing the pull test.


What is the length of the ferrules you are using? You should be using at least a 8mm length ferrule. We 8mm and we can slide them right in and they won’t come out until you press down the release. We did make a mistake once and used a size less then 8mm and it wouldn’t grab.


They don’t slide out. It takes a hefty tug but does not pass the pull test


It really depends on how you gauge your pull test. At my most severe pull test, no they wouldn’t pass. I guarantee it, but the force that they are likely to face in a match is probably about a third of that pull test. If it is taking a pretty hefty pull, I believe they should be fine.


That sort of makes me feel better, and with good strain relief I don’t think there will be a problem, but still makes me wonder about the design of the connection. I do like how much easier they are to place than bare wire, and the protection from individual stray wires.