Wire too big for Victron charge controller

[Nord Sal]

A pin terminal connector should work (as opposed to the ferrule connector, which is the same size as the wire). In the case of a pin connector for an 8 AWG wire, the pin is 2.6 mm dia.

I have a 75/15 solar charge myself and used this type of connector to connect 12 AWG wires from the panel to the controller. The pin diameter is the same (2.6 mm) as for the 8 AWG.

https://www.digikey.com/en/products/...180599/1864661

https://www.digikey.com/en/products/...ASwB2AcxABfKUA

[Wotname]

Each to their own but I wouldn't use a round or semi round termination in the Victron square style screw clamp. I suppose you could hammer it flat in a pinch!

[s/v Jedi]

The OP used 8AWG which is the right thing to do, as the sizing is for preventing voltage drop rather than maximum current carrying capacity.

The comments that a crimped ferrule isn’t needed for the victron terminals is correct, but so are the comments that it is recommended to do anyway because it protects the small strands, prevents shorting from loose strands at the terminal block etc. I recommend to dip the strands in dielectric grease before crimping in the ferrule.

The correct method to make this fit is to remove strands to make it fit. Do not use smaller wire connected to the 8AWG, which only introduces more potential trouble points in the circuit.

[HeinSdL]

^^Exactly.

Is there some confusion here? The wire size is not specified in such a way as to prevent overheating, etc, but only to absolutely minimize voltage drop over the relatively long length of cable. So the entire cross-section of wire does not need to go into the socket. Just remove some strands and shove it in I would say too. It will absolutely not overheat, catch fire or introduce some unwanted voltage drop.

[Tupaia]

Bootlace ferrules to work properly require the bare wire to extend to through the fitting and crimp onto the sheath.

A much better solution is a cable reducing lug or pin. These are specifically designed to join dissimilar cable sizes or reduce a large cable to a pin end or spade for connection into an appliance.

[s/v Jedi]

About ferrules: as Rod writes in his wiki article, the cheap crimpers do not crimp as tight as the expensive, professional ones. In this case this normally isn’t a problem, because the terminal provides the clamping force for mechanical retention, but it can lead to this phenomena where the 10AWG ferrule doesn’t fit in the terminal, while the crimp from an expensive crimper does fit.

The real cause is that while the terminals do provide some room for variation, they are made for metric wire sizes, not American gauge sizes. 10AWG is 5.26mm2 which is a borderline fit for a 2.5mm2 terminal and the ferrule wall thickness is still added to that.

Your options are to remove more strands or buy a more expensive crimper.

[Wotname]

Originally Posted by Tupaia

Bootlace ferrules to work properly require the bare wire to extend to through the fitting and crimp onto the sheath...

Err -

Refer to Ron's (Maine Sail) link in post #13

Copied here - https://marinehowto.com/terminating-bare-wire-ends/

[Wotname]

Hmm... the Victron 75 / 15 should accept a 6mm2 wire which is notionally bigger than 10AWG although both need to square compressed.

[Tupaia]

Originally Posted by Wotname

Err -

Refer to Ron's (Maine Sail) link in post #13

Copied here - https://marinehowto.com/terminating-bare-wire-ends/

My point was that fitting a correctly sized ferule requires all of the wires to extend to the end and it is likely that the wire sheath will not fit into the collar. I also believe that Victon do not like ferule terminations to their equipment. Far better to use a reducing link to add a short piece of smaller gauge wire.

[GordMay]

Nord Sal draws a subtle, but important, distinction [ https://www.cruisersforum.com/forums...ml#post3781674 ], between a Quick Connect Pin Terminal and Crimp Wire Ferrules; where the pin area, on a Wire Pin Connector often has a smaller diameter than the wire. Wire Ferrules, on the other hand, will crimp on the barrel end of the terminal, so the diameter of the connection will be the slightly larger than the actual wire itself.
DigiKey explains it well ➥ https://forum.digikey.com/t/wire-fer...-terminal/1403

If it fits, use it.

[GordMay]

Originally Posted by Wotname

Refer to Ron's (Maine Sail) link in post #13
Copied here - https://marinehowto.com/terminating-bare-wire-ends/

My objection to using a Wire Pin Terminal, was to the addition of an extra wire joint, which will add more:
- Circuit Resistance, hence voltage drop
- Potential point of failure
- Cost & effort
to the circuit.

On the other hand:
Mainsail’s Marine How To article [ https://www.cruisersforum.com/forums...ml#post3781435 ] references Weidmuller’s White Paper*, which highlights the advantages of ferrules:
‘Analysis shows that stranded wire with ferrules demonstrate resistance, over time, that is similar to solid wire.’
‘Over time, corrosion of the unprotected stranded wire produces an increase in contact resistance.’

* “Ferrules: Your Best Insurance Against Costly Connection Failure”
➥ https://www.goies.com/Weidmuller_Fer...hite_Paper.pdf


So, perhaps, on balance, my objection to an additional joint was unjustified.

Good thread! Much food for thought, given the various competing trade-offs.

[s/v Jedi]

If the terminal where you insert the wire is short, it is indeed important that the wire strands go all the way to the end of the crimped ferrule.

The way to ensure this requires an additional tool: flush cutting side cutters. Niw you strip the wire a bit longer, stick the strands in the dielectric grease, then into the ferrule where they stick out, then crimp and cut the excess off flush with the side cutters. This works very well as long as you have the flush cutting side cutters instead of similar cutters from the likes of Stanley etc.

[CarinaPDX]

By far the best solution is to use pin terminals, which I have done in such situations. They crimp on to the wire but have pins that are smaller. They are available bare or insulated.

Greg

[jordanbigel]

Originally Posted by s/v Jedi

The correct method to make this fit is to remove strands to make it fit. Do not use smaller wire connected to the 8AWG, which only introduces more potential trouble points in the circuit.

This is what I said in post #9 - or rather, I said this is what I have done in the past - and I asked if someone could explain to me why this is not the right approach. I was hoping one of the electrical gurus could explain why this is a bad idea.

So far no one has done that, and obviously you agree this is an acceptable solution.

Is there any counter-argument against this approach?

[Wotname]

Originally Posted by Tupaia

My point was that fitting a correctly sized ferule requires all of the wires to extend to the end and it is likely that the wire sheath will not fit into the collar. I also believe that Victon do not like ferule terminations to their equipment. Far better to use a reducing link to add a short piece of smaller gauge wire.


Attachment 275844Attachment 275845

I understand your point however using an uninsulated ferrule solves the problem. An uninsulated ferrule does not extend over the insulation; in essence it allows for the conductors to be formed from a circular cross section into a square cross section.

There seem to be some confusion about terminology on this thread. In my world, there is world of difference between a Pin Terminal, a Ferrule (AKA Bootlace Ferrule), Stalk Lug etc.

Ferrules can be insulated or non-insulated. Additionally the cross section of insertion part is either square or hexagonal dependent on the crimp tool used. Square is by far the most common and is what should be used square clamp set screw terminations i.e. the style used on Victron products. The hex cross section is used for round entry screw terminations. Ferrules are also know as 'sleeves' and 'cord end' terminals .

FWIW about Pin terminals - The cross section of the insertion part of a Pin terminals can be flat, semi round or round but never square. While the flat version is suitable Victron (square) terminals, I would not use the round or semi round forms. Maybe because I am fussy!

Shown is an uninsulated ferrule, an insulated ferrule and a stalk lug, they should not be confused with each. None of these are Pin terminals.