Wire Ferrules - When to Use, How to Crimp, and UL 508A Guidelines

In this video we go through UL 29.3.6 A guidelines of UL 508A to determine when you should use ferrules and how to properly crimp them.

Don't forget to like and comment on our videos and subscribe to our channel.

Items used in this video:

[richardzubrick]

I was always told that "cage clamp" style terminal, such as the Wago brand, was only for stranded wire, not for ferrules. However the Wago website states that the cage clamp terminals CAN be used with ferrules. I stand corrected! Great videos by the way...

[adisharr]

Insulated ferrules are a must for spring terminal insertion IMO. Really reduces the the potential mistake of inserting a wire too far and partially landing on the wire insulation. Funny story, we had a young guy wiring up his first panel and he didn't know you needed to strip the wires. He did half the panel that way before we caught it HA! :)

[GenericUserUnknown]

Thank you for taking the time to create these great, informative videos.

[mikefochtman]

I like the insulated ones, but I have run across some items where the terminals were too close together to accommodate insulated ones. So had to switch for that job. Nice video. And so right about the crimping tool, a good one is worth it.

[DG_Fabrication]

Great video this is the explanation I have been looking for!

[steffankaizer]

great video. i am pretty sure the insulation on the ferrule is to ensure that the wires are still "finger save" when someone needs to replace a part in the field while other parts of the cabinet are still energized. some wires have the insulation kind of loosely so it retracts back over time and exposes the copper. always strip a little shorter than the ferrule then push the wire even into the ferrule to shove the insulation back

[Ozzy]

Great video Tim, what brand wire do you recommend for 14 to 16 awg 600 volt rated ? Any online source you can recommend?

[krzysiektraba]

Interesting 3:30. In my opinion, when they say that you should crimp the right crimper, they mean a crimper dedicated to each wire gauge. I work in Siemens factory, and the type of red universal crimper you use, we can only use for double ferrules. For single ones, there is a crimping tool that has an individual channell for a specific wire gauge, like yours a second red crimper in 4:50. Sorry for my english.

[mumblesjustin]

Not sure if I missed it but ferrules also allow stranded wire to be terminated on devices that manufactures specifically state solid wire must be used. In other words the ferrules turns stranded wire into solid wire to meet NEC. And since NEC doesn’t allow multiple wires under under one terminal, using the dual wire ferrules allows you to terminate two stranded wires under a single terminal rated for a single wire and comply with NEC. Because once the two wires are crimped with the two wire rated ferrule the connection is reclassified as a single wire termination point. This is all outlined in both UL and NEC and feral manufacturer specs. I just don’t remember which sections off the top of my head.

[happyhusky]

Can I use these Ferrules to crimp wire for home audio spring connector in my Onkyo amplifier?

[christopherlyons]

Thanks for the video. A couple questions. First after you strip your wire, should it be twisted prior to inserting it into the ferrule? Or should it be inserted straight?

It's hard to see but when I zoom in on your panel it looks like you are using ferrules on your PLC connections (you can see the yellow insulated edge of the ferrule on those connections) but it looks like you are not using ferrules on the lower row connections (can't see any insulation color on those connections). If ferrules weren't used on those lower connections, why didn't you use them? Are there any type of components that you don't use ferrules on?

It looks like you didn't heat shrink your wire labels before installing them. Why is that? In general when do you recommend heat shrink labels have heat applied? And how close to the ferrule should labels be applied? I find it tough sometimes to not melt a bit of the ferrule insulation if the labels are placed too close. Are there any UL specifications regarding where labels are placed?

Appreciate any help. Thanks.

[patelp]

So i am using a screw terminal and the Ferrule is too long to pit because otherwise part of it sticks out but it still clamps nicely. Should I cut the extra leng rn from the ferrule? It’s 16AWG at most 30A of current

[windward]

Companies who make electrical panels for their equipment like CNC manufacturers, will have internal requirements to meet UL 508A with UL 486 consideration (pull strength, etc.), and also have best practices based on actual testing and operational experience in the field.

A screw pressure connection in UL 508A as compared to the NEC many times for conductors10 AWG and smaller are addressing the basic differences between stranded and solid conductors in connecting devices and circuits in a panel. A simple example is with house romex wiring solid 12 AWG copper, as just one example, which would be connected to a breaker in a panel. In this case the breaker screw pressure connection is designed for a 12 AWG solid wire (and will list the required screw torque), that is, assumes that there is no separation of strands which is valid because it is a solid conductor so there are no strands to separate. But, what if we wanted to connect THHN/THWN 12 AWG stranded wire (which is also NEC listed as an approved wire type) to the same breaker screw pressure connector. What I have found is there is no standard in how a screw pressure connection is designed. Some seem to accommodate stranded wire better than others. Some designs are so bad that you know the connection will loosen if the strands move or shift due to machine vibration or conductor heat cycling. The solution is to use a ferrule when using stranded wire, with the added flexibility of selecting the ferrule crimp shape (square, hex, semi-round, etc.) to best accommodate the device screw connection design.

The NEC (as UL listed) does not require any derating or special consideration when using stranded copper wire with a ferrule. However, most companies will require the method to be listed (tested) through the manufacturer of the ferrule and how it is used. This basically results in the ferrule and crimp tool coming from the same manufacturer like Weimuller, as an example, with best application practices documented through a written approved document or a manufacturer's guide. A bonus is if the company makes dual wire ferrules which is a very good and inexpensive way to make a splice.

As mentioned in the video, if you are crimping eyelets to a screw terminal strip it is very similar in using ferrules because the eyelet and the crimper used will be tested to give a complete connection and pass UL 486.

The panel in the video did not show very large gauge wire stranded wire terminations. If the connection is to a screw connection lug (one where you insert the cable with a single Allen screw) with stranded wire a ferrule will be used, in my experience up to about 2/0 size, and Weidmuller makes ferrules for large conductors (I stock up to 1/0). If the connection is to a bus bar then a bolted crimp lug is used. Here again to meet UL 486 the crimper (which is usually hydraulic at a minumum of 6T up to about 2/0 copper), lug and die are specified for a specific NEC stranded wire type (lay), usually coming from the same manufacturer although with more mix and match options than ferrules. Common would be using W dies from Burndy that can be used in many different 6T crimpers, from obviously Burndy, but also Panduit, Greenlee and others. For larger conductors you would move to a 12T crimper with U die index D.

In panel making we have the added difficulty of using specialty large size conductors that have the proper rating but have different stranding than NEC class B (standard THHN/THWN). If the connection is into an Allen screw compression lug we can use a ferrule, but if it is to a bolted lug we have to then choose the lugs and the dies (may require multiple crimps) that will produce a complete solid cold welding of the joint. Which means you have to run some test crimps, saw through the crimp and inspect the quality and completeness of the crimp, then document the procedure as part of the assembly instructions. I have seen high stranding copper wire (like type K welding cable) used with an Allen screw compression lug with the expected poor connection and overheating (through thermal camera inspection), which would be easily remedied using a ferrule. However, when using a bolted lug you don't really know the performance of the crimp until you test it. You see this a lot in Marine panel applications, because the conductors are made of fine stranded tin plated strands which has no approved and tested "system" to make the crimps.

[evelynricahrds]

I recently caught our tech installing several wires into individual terminal connectors and purchased ferrules rated for 2 wires to solve the issue. Our quarterly 508a audit should be any day now so I guess I'll find out what he has to say about it. lol.

[kingofslotsmillion]

I work in a control building line . And was just given a Farrel kit to use. But some terminations require 2 wires to jump from device to device. Can I use 1 Ferrell for 2 wires? Or how do I terminate 2 wired

[johnbryan]

Wow lots of great info! Great video!!!

[dimmuo]

I`ve been using ferrules for all multi-core wires of 0.5 to 6 sq.mm (sorry for not AWG interpritation, we don`t use it in Ukraine). That`s the way to keep wire managing inside the control box accurate and to re-tight easily if needed. Non-insulated ferrules in my opinion is non prefferable in term of extreme wire bending angles per length between the wire insulation edge and ferrule`s bottom.
But of course you should follow the local guides.

[siggitiggi]

Funnily enough in my country they require ferrules on stranded wires with screw terminals, as the screw terminals rated torque sometimes outstrips the wires malleability resulting in strands breaking when tightened (as in screw directly onto a wire).

[ga]

Question(s):

I saw a video where someone took 3, 14awg wire into 1 large ferrule.

I know there are ferrules for double wire 14 awg.

Is there some for 3? Is this allowed?
It seemed very odd for me.

[subbunathi]

Thank you sir very nice explained if you don't mind please requested for you chiller control wirinig please
Thank you