Multiplus-II AC wires pull out easily!?

[Firstascent]

I’ve got a big issue, I was so excited to finally do the final AC connections only to find out that my wires just pull right out, and easily too, there is little resistance and it can slide out.
I hate these spring terminals, give is screw clamps!

Anyways, have you guys seen or heard of it this bad before? Open to any advice/suggestions/comments.

Multiplus-II 2x120 model
I know there are mixed feelings on using stranded wire. I used 6/4 stranded wire with ferrules.
I stripped the wire per the Victron manual
I used ferrules of the correct length per the Victron manual
I used a 2.5mm flat blade screwdriver inserted correctly into the terminal correctly to aid in wire insertion. (Yes the correct top hole, not the one the wire goes in)
I used high quality UL listed ferrules and quality crimping tools.

I took a short vid but I can’t upload vids here. The photo is just a screen grab from the video of me very easily pulling the wire out as if it weren’t clamped down at all.

I’m pretty picky on my work, and I followed the manual as well, but I’m human. These are pretty straightforward though so not sure of anything I could’ve done wrong.
Always good to get an extra set of eyes and info, so here I am asking

 

[740GLE]

This is my one big concern for picking up a
Multiplus.

My only thought is the tension of those terms is for electrical connection not strain relief, there’s strain built into the enclosure relief for all cabling right?

 

[RCinFLA]

Like this.

 

[RoadTurtle]

Sigh. I struggled with this myself.

First get rid of the ferrule. MP doesn't seem to like those. 2nd, make sure the stripped distance is long enough. IRC it's 3/4", and I made mine ever so slightly longer. Once I got rid of the ferrules, and stopped trying to release the clamp and just slid the wire into the clamp, it went right in and locked down.

I agree, this is a terrible design.

 

[Firstascent]

Thanks everyone, yeah I've "heard" (even from Victron distributors/installers) that they apparently don't recommend them. Which is fine if you simply say "don't use ferrules" in your manual! But instead they recommend a specific size of ferrule and silently say not to use them.
Not cool from a company as big and respected as Victron.

@RoadTurtle I did just that earlier today. Cut the ferrules off, stripped the wires about the same as you, I believe it was 7/8" and they went in and felt locked in.

I hooked it up to 50A shore power, ran a couple A/C units, and everything looked great as far as temperatures go so I think this should be good. But wow what a mess getting here haha

 

[RoadTurtle]

Thanks everyone, yeah I've "heard" (even from Victron distributors/installers) that they apparently don't recommend them. Which is fine if you simply say "don't use ferrules" in your manual! But instead they recommend a specific size of ferrule and silently say not to use them.
Not cool from a company as big and respected as Victron.

@RoadTurtle I did just that earlier today. Cut the ferrules off, stripped the wires about the same as you, I believe it was 7/8" and they went in and felt locked in.

I hooked it up to 50A shore power, ran a couple A/C units, and everything looked great as far as temperatures go so I think this should be good. But wow what a mess getting here haha

The guy that had a cargo trailer and burned up a MP, Victron told him to use ferrules.

 

[Firstascent]

The guy that had a cargo trailer and burned up a MP, Victron told him to use ferrules.

This is what I don't like and it's so confusing. Hearing completely different sides from the same source. I'm somewhat glad it was so bad and it popped right out because it was SO clear there isn't good contact with them and could've been dangerous!
I prefer not to burn down my RV.

There were a couple ferrule connections on my AC-in side that were a little difficult to remove, but I wasn't going to chance it. Even though a couple were difficult to remove I could push them in/out about 1/4" so I think it was more of the ferrule being slight stuck. but either way, you shouldn't be able to move the wire in/out at all haha

 

[timselectric]

IMO
Ferrules should only be used in set screw type terminals. This is to keep the set screw from damaging the strands. Otherwise, you get a better connection if the strands are allowed to fill out the terminal.

 

[LydMekk]

Well, strands are not good in PV connections. I prefer ferules to keep the strands contained and minimize the offchance of arcs between the strands.
Altogether I prefer ferules in all my inverter connections, but that's me ^^ it speaks to my slighly OCD germannic state of mind LOL - ordnung must sein...

 

[740GLE]

I also feel ferrule are more a requirement on fine multi-stranded conductor that doesn’t have the same rigidity to insert without folding over, a ferrule provides that lateral support for full insertion.

When dealing with 6awg (which IMO is overkill for 3k inverter) and each conductor leg is only 7 strands that’s a thick & stiff cable! No lateral support needed.

This is just my guess as Victron doesn’t know the number of strands you’ll be using for your conductor they CYA with stating ferrules are good.

 

[timselectric]

OCD is also why I do most of the things I do.
And 40 years of experience.

 

[SamDeleted]

Not very impressive for such an expensive item

 

[Checkthisout]

Why are you releasing the clamp when you insert the cables?

Just push the wires in.

 

[RCinFLA]

#6 wire is appropriate for 50-amp pass-through relay. #6 close to marginal gauge for AC output amperage that could go to 75 amps with maximum load shaving support, not that I would really recommend doing that, for other than startup surge current loads.

Quattro 3K model have clamp screws terminal strips.

 

[Checkthisout]

#6 wire is appropriate for 50-amp pass-through relay. #6 close to marginal gauge for AC output amperage that could go to 75 amps with maximum load shaving support, not that I would really recommend doing that, for other than startup surge current loads.

Quattro 3K model have clamp screws terminalheadaches.

The multiplus ii is a cost-cutting build.

 

[RoadTurtle]

Why are you releasing the clamp when you insert the cables?

Just push the wires in.

This is the extent of the instructions, and I interpreted this to mean the clamps had to be released to attach the wires.

A blade tool of 2.5mm (e.g. a screwdriver) is required to operate the spring loaded AC terminal blocks.​

The terminal blocks can be found on the printed circuit board, see Appendix A.​

Do not invert neutral and phase when connecting the AC​

 

[Checkthisout]

This is the extent of the instructions, and I interpreted this to mean the clamps had to be released to attach the wires.

A blade tool of 2.5mm (e.g. a screwdriver) is required to operate the spring loaded AC terminal blocks.​

The terminal blocks can be found on the printed circuit board, see Appendix A.​

Do not invert neutral and phase when connecting the AC​

Oh dear..