Using Ferrules

[Nomore9-5]

I have to reinstall the hardwire version of a 50 amp Surge Guard . I would normally insert the bare conductors into the screw terminals as usual however I'm wondering if anyone has done this using bootstrap ferrules . My understanding is they make for a better connection since conductor wires aren't splayed apart by the screw or some of the wire stranding gets cut

[Nomore9-5]

My apologies the ferrules I'm asking about are bootlace not bootstrap

[Bob K4TAX]

In most cases, I will flow solder onto the tightly twisted strands and then insert the wire into the screw terminal. But again, that's how I do it.

Bob

[Touch racing]

I typically use ferrules on fine stranded wire. I believe the set I have will work up to 7 gauge wire. I’m not using ferrules on my hardwired EMS.

[Nomore9-5]

Originally Posted by Bob K4TAX

In most cases, I will flow solder onto the tightly twisted strands and then insert the wire into the screw terminal. But again, that's how I do it.

Bob

I have very little experience with soldering Does the solder have enough strength to hold the strands together when things when you tighten things up .

[MGD1961]

Originally Posted by Nomore9-5

I have very little experience with soldering Does the solder have enough strength to hold the strands together when things when you tighten things up .

Soldering is not the best idea because if the circuit were to heat up for come reason the solder could melt and collapse making the connection even worse.

Ferrels are the way to go. BUT you must use the right crimpers or they would have a good connection inside the ferrel. It must have a 4 sided crimp and must be exactly the right size.

All that said soldering is better than not. Short of a large investment do that.

[corn18]

I don't like using ferrules or solder. Ferrules reduce the contact area of compression type connectors. Solder is not recommended for mobile applications. Just leave the wire bare.

[PhilFromMaine]

I agree with everything said so far. I have found that ferrules take a certain fineness to do properly. So far, I don't have that fineness. The last time I had your issues I doubled or tripled up the stranded wire and stuffed the hole and then torqued down the set screw. I also clamped down the wires to the backboard so that if the wire was pulled on the clamps would take the stress, not the connection.

[MGD1961]

Originally Posted by corn18

I don't like using ferrules or solder. Ferrules reduce the contact area of compression type connectors. Solder is not recommended for mobile applications. Just leave the wire bare.

I would respectfully disagree and ask whose recommendation is that?

This is not an argumentative or smart A## question. I would genuinely like to know

I don’t think it’s the national electrical code. Could be wrong but they don’t dictate mobile applications do they?

I know for a fact that ABYC dictates exactly the opposite unless there is an “anvil “ installed in the contract between the screw and the stranded wire.

And as we all know we should not be using solid wire in a mobile application

The entire idea of a ferrule is to keep stranded wire from twisting and squeezing to the sides of the contact screw. Many circuit breakers say for solid wire only for just this reason

The screws in some connectors will bottom out before they fully tighten as well

Ferrules turn the end of the stranded wire into a solid wire for all the reason previously stated.

[Aussieguy]

I do what Phil from Maine said ... double it over if needed to fill the hole better
then I use good pliers to twist the wire onto itself

[corn18]

Originally Posted by MGD1961

I would respectfully disagree and ask whose recommendation is that?

This is not an argumentative or smart A## question. I would genuinely like to know

I don’t think it’s the national electrical code. Could be wrong but they don’t dictate mobile applications do they?

I know for a fact that ABYC dictates exactly the opposite unless there is an “anvil “ installed in the contract between the screw and the stranded wire.

And as we all know we should not be using solid wire in a mobile application

The entire idea of a ferrule is to keep stranded wire from twisting and squeezing to the sides of the contact screw. Many circuit breakers say for solid wire only for just this reason

The screws in some connectors will bottom out before they fully tighten as well

Ferrules turn the end of the stranded wire into a solid wire for all the reason previously stated.

No code to quote and I don't feel like doing any research.

Round ferrules do not squish down so screw type connectors will only contact a very small area on the top and bottom of the ferrule. Compare that to the contact area of a stranded wire in the same connection. A LOT more contact area. I think there are ferrules that do squish and that is the kind I would use.

Soldering a stranded wire in a mobile application is not a best practice. The soldered end is solid but it creates a strain point where the solder ends. And it has the same contact area issue as ferrules, but at least the solder can give a bit and get squished for more contact area.

You ever see a soldered wire or ferrules on a factory vehicle?

[MGD1961]

Originally Posted by corn18

No code to quote and I don't feel like doing any research for you.


Round ferrules do not squish down so screw type connectors will only contact a very small area on the top and bottom of the ferrule. Compare that to the contact area of a stranded wire in the same connection. A LOT more contact area.


Soldering a stranded wire in a mobile application is not a best practice. The soldered end is solid but it creates a strain point where the solder ends. And it has the same contact area issue as ferrules, but at least the solder can give a bit and get squished for more contact area.


You ever see a soldered wire or ferrules on a factory vehicle?

Yes. I see them in factory applications every day. What is a Deutsch connector. Or a Delphi connector or a DIN connector? They all have in common that the stranded end is contained

I’m sorry. I work with ferrules all the time. Sometimes daily. Probably 10s of thousands of successful connections under my belt and I’m here to tell you that ferrules DO squish and make a full broad contact with the screw. They also CONTAIN THE STRANDS. Besides, once the surface area exceeds the cross section of the wire it’s a moot point. The current potential never increases. Ferrules after they are crimped are square. Not round. The surface area well exceeds the cross section.

No engineer has ever said “just cram it in there and tighten it down”

The OP already knew better. He asked for people with experience to discuss it. Not how to do it wrong

[corn18]

this is the problem. No way I use ferrules for high amp connections. Change my mind....

[PhilFromMaine]

Originally Posted by corn18

this is the problem. No way I use ferrules for high amp connections. Change my mind....

I understand your personal preference not to use furrules. But even with a casual graphical check of your supplied images, it looks to me that the bottom one roughly matches the surface area of the wire. Like you said, there are formulas that could be used in a proof if one were to really care.


I would like to think that some engineer did the math for the manufacturer and that it meets good engineering design standards. I have already forgotten what the OP is connecting these wires for, but most likely the wire size and connectors have a substantial amount of safety factor built in.

[corn18]

Originally Posted by PhilFromMaine

I understand your personal preference not to use furrules. But even with a casual graphical check of your supplied images, it looks to me that the bottom one roughly matches the surface area of the wire. Like you sssaid, there are formulas that could be used in a proof if one were to really care.


I would like to think that some engineer did the math for the manufacturer and that it meets good engineering design standards. I have already forgotten what the OP is connecting these wires for, but most likely the wire size and connectors have a substantial amount of safety factor built in.

Yeah, my graphical skills are poor. I know that when I pulled the 6 ga wire out of my MPPTs to move them, the stranded wire was flat as a pancake. Same when I pulled the ends out of the DC double pole circuit breakers I use to disconnect the panels. Same with my Orion XS. That is a lot of good surface area to transport electrons at high amps. I have some 6 ga ferrules I bought off of Amazon but the ends are solid. No way I would use that in this application. The ends won't squish. Do they sell ferrules where the ends flatten? If they do, that is definitely a good option and my mind will be changed.

[MGD1961]

Originally Posted by corn18

this is the problem. No way I use ferrules for high amp connections. Change my mind....

Read my post. Learn how to crimp a ferrule

THEY ARE NOT ROUND. AND THEY DO CRUSH.

I use a Pz 6/5 on small wires and a PZ 3 on larger wires.

[MGD1961]

Originally Posted by corn18

Yeah, my graphical skills are poor. I know that when I pulled the 6 ga wire out of my MPPTs to move them, the stranded wire was flat as a pancake. Same when I pulled the ends out of the DC double pole circuit breakers I use to disconnect the panels. Same with my Orion XS. That is a lot of good surface area to transport electrons at high amps. I have some 6 ga ferrules I bought off of Amazon but the ends are solid. No way I would use that in this application. The ends won't squish. Do they sell ferrules where the ends flatten? If they do, that is definitely a good option and my mind will be changed.

Ferrules with a closed end also have a little hole in the side because they are intended to be soldered. Not crimped

[corn18]

Originally Posted by MGD1961

Read my post. Learn how to crimp a ferrule

THEY ARE NOT ROUND. AND THEY DO CRUSH.

I use a Pz 6/5 on small wires and a PZ 3 on larger wires.

So those are not anything like the pin ferrules I am thinking of. Those are crimp ferrules and I like them. Consider my mind changed!

[bkfowler]

Originally Posted by MGD1961

Ferrules with a closed end also have a little hole in the side because they are intended to be soldered. Not crimped

Many times the small hole is for inspecting to make sure the conductor is sufficiently inserted into the device after a crimp has taken place.
Those little holes are almost impossible to get solder to flow into.

[DJ252]

I used them for the first time, when I did the electrical upgrades on our TT.

I'm a convert.

Its a superior connection. On fine stranded wire, a no brainer decision, on anything that needs to be repeatable, or anything you don't have good access and sight of.

My kit goes up to 10ga.