Ferrules on PDP 30/40 amp WAGO connectors?

I’ve always been curious: do people use ferrules on 40 amp or 30 amp circuits connected to their PDP WAGO wire cage connectors? I’ve heard of folks using 12 AWG ferrules (insulated? non-insulated?), but I’m not sure what crimp shape would work best. If your team does this, I would be interested in hearing what prompted you to start using ferrules and if you have had any issues.

So our team does not use ferrules in the 40-30 amp slots on the robot. We will normally just strip the wire back about a half inch or so and then we will just open up the WAGO connector and put it in. we only use ferrules in the VRM PDP PCM and CAN slots, and even then if you tin the end with solder you can put it in without the ferrule

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We use ferrule everywhere we can, even though I’ve heard multiple people not recommend it. A square crimp would be the best for WAGOs to maximize surface contact. Trapezoids typically have little tabs that limit contact it seems, and hexagon just has smaller sides. There may be more crimps, but based off the tools we have tried, square is the best.

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I don’t see the need. Wago connectors retain stranded wire fine, sans ferrule. At that point, the ferrule is just another point of failure, and an additional cost.

If you don’t use ferrules for your smaller wiring, please do. Weidmuller connectors work stunningly with ferrules, and it’s saved us quite a bit of hassle over the last two years.


Thanks everyone for your insights. We use ferrules on all smaller wiring (except for CANBus) and we’ve found it incredibly useful. We have a crimper similar to this one and I think we’ll try crimping on our 10/12 AWG connections into the PDP during this offseason to see if it makes any difference for us.

PZ6 Roto has worked really well for us, using insulated ferrules.

We use this kit (actually linked 2 posts above one that you noted).

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My prime recommendation: follow the manufacturer’s intent; no ferrules. These connectors are designed for bare stranded wire.

If you’re going to use ferrules, go square to get the greatest amount of contact. You may as well use the insulated ones so you’re holding the ferrule rather than the wire on insertion and removal.


I would agree with this the surface area is maximized without ferrules because of the way the terminals work. I would just recommend hand twisting the wires before putting them in the terminal so they go in easier

We have a couple of “trainer” robots that get a lot of rounds of assembly/disassembly. The wago/10-12 gauge wire combination is difficult for students who are learning how to open the wagos. The 30/40 amp wagos are effective when used correctly but require a deftness that comes with experience with them, which beginners do not have. In the hands of a newcomer the strands of wire invariably become mashed and splayed out and then difficult to twist back together.
We have found that using ferrules (mcmaster) make it much easier for beginners to have success with the 30/40 amp wagos. I recommend ferrules highly for any robot that is used for training.
For the comp bot we don’t use the ferrules; experienced students twist the strands and carefully install them. And then we check for whiskered strands.

The Weidmuller connectors used on the VRM, PCM, roboRio, and PDP are designed to be used with ferrules.

The Wago connectors used on the PDP are designed to be used with stranded wire.


We run with ferrules for ease of assembly/disassembly - even with experienced students & mentors, I like that it prevents whiskering and makes replacement/reassembly extremely easy.

The ferrule is from JamesCH’s kit, and it definitely has a strongly rectangular profile that is reducing contact area. Reading this thread I’m considering moving to hex or octagon crimp to see if we can get better surface area.

We wring out our drivetrain pretty hard (bumping up against brownout conditions with 3 miniCIMs/side) and I haven’t detected any failures at the ferrule to PDP interface. Now I want to look closer for any warming and maybe run some comparisons.

interested if @ozrien can comment on use of ferrules on 30/40A connectors on the CTRE power distribution board, particularly any impacts on warranty?

FRC #1018 has been using ferrules the past few years. We are using finely stranded 10 AWG and 14WG conductors at the PDP. Agree that the ferrules preclude wiskering. They are also irreplaceable when it comes to blind work on the PDP terminals. We are also using square crimp tools that provide a significant wire AWG crimp range.

So this year was my teams 3rd year in FRC and for our first two years we didn’t use ferrules on anything, since we were learning the ins and outs. As I got deeper and deeper into the rabbit hole of FRC, I learned that insulated ferrules are the best thing on this Earth. We used Orange 22 AWG Ferrules on the small CAN Bus and radio power, like normal. The White 20 AWG on all compressor wires and power for VRM, PCM, and Rio. And we actually used the Green 10 AWG on some 12 AWG wire, yes I know it’s wrong but we didn’t have anymore gray ferrules, and they worked perfectly for the PDP. They made a nice perfect dip for the trapdoor to latch onto. In our experience with raw wire versus ferrule wire in the PDP, the ferrule wire is easier to swap as needed, and latched better than the non ferrule wire. Plus it looks cooler in my opinion :heart_eyes:

It is hard to find the exact part number of the Wago power connectors on the PDB. But the Wago cage clamp terminals are UL listed for solid, fine stranded, and ferules. Since the crimp shape is not specified, any would be acceptable although the square or trapezoid are probably better for the Wagos.

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We have always used ferrules whenever we can. We’ve never had a problem with them. Use square crimp.

548 has never used ferrules on WAGOs. The connector is definitely made for individual strands. If you are having trouble, remember these two things:

  1. The way to open a WAGO is to insert the screwdriver, lift the screwdriver up, then push the screwdriver in deeper. It will hold the screwdriver in place and the connector open. Then just stick the wire in. The hole will be nice and wide. Yank the screwdriver to finish the job.
  2. Either get a WAGO Tool or spend a few minutes on a belt sander flattening out the stem of a normal flat-head screwdriver. It works much better than just some random flat-head.
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Do you have source for this?

I don’t know the exact model number (would need confirmation from CTRE), but I think they’re the WAGO 745 series, similar to this: https://www.wago.com/us/pcb-interconnect/terminal-strip-with-jumper-slot/p/745-302.

Per the datasheet, ferrules are allowed, but not up to the same wire diameter as solid or stranded. In addition, WAGO’s “technical explanations” PDF has a lot more detail (unfortunately, it’s a bit harder to parse out, as it covers a lot more of their product line). Per that document (page 7), bare wire is recommended over ferrules (one possible anti-splaying method):

The IEC 60999-1/EN 60999-1/VDE 0609-1 Specification (Section 7.1) requires that: Clamping units must be able to connect unprepared conductors. Under normal operating conditions, direct clamping (i.e., directly connecting a conductor to the terminal block’s current bar) provides optimal contact quality, because all risk factors arising from anti-splaying methods are prevented.

That page of the document also talks about what kind of ferrules to use if you need to use ferrules.


Thanks for that reference. Although I like ferules, I never felt the need for them on PDB, but never could put my finger on a technical reason.

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On a previous team, we installed ferrules on all our wiring, I think in 2016. Half way through the season, the 12AWG and 10AWG wires started slipping out of the ferrules. I had pull-tested all of them after the students crimped them and did their own pull-tests and they were all good at the time of installation. We ended up pulling all the ferrules off the 12AWG and 10AWG wires.

I suspect that the ferrules loosened up on the larger wires because either the crimper did not compress the ferrule/wire sufficiently and/or the ferrules were too thin and “stretched” after crimping. I noticed that the thickness of the “tube” on the ferrules is much thinner than the corresponding part of the normal red/blue/yellow crimp lugs used for connecting to components like the SPARK.