Multiplus II Installation: I've been impressed with Victron up until now

DIY
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I’ve always loved my Victron setup and have recommended the brand to many of my RVing friends as being dead simple but incredibly reliable and configurable. After the install of my 3000VA 120x2 MP2, I don’t know how I feel anymore. Call this a rant, or maybe lodging a complaint. I just feel like someone at Victron needs to know if they don’t already as these are all design choices that add no cost to the unit itself.

  1. DC Connections: one of the positive DC terminals cannot be connecting without twisting the wire and/or flexing the header for the multipurpose jacks above it. The lugs are physically too close - I felt like I was going to damage the multipurpose headers by bending them and you have to bend them since the cables have to fit through a closed oval. Which brings me to my next complaint…
  2. Connection Inlets: why in the world are these not open on the top? It is MUCH easier to simply lay a cable into the unit and on top of the corresponding lug than to feed a 2/0 AWG wire through the inlet and then bend it mercilessly with plyers until the lug lines up with the eye. It isn’t water tight so not sure the reason for this design decision. Getting rid of the cable inlet would make measuring cables far more accurate and cut the installation time at least in half.
  3. AC-In Connection Inlets: per the manual, the minimum wire gauge to be used is 6AWG and there are 4 conductors to connect. The inlets aren’t big enough for a single 6/4 AC wire so you have to move over to the next inlet which doesn’t line up with the connector. This makes no sense. All they need to do is change the inlet to be “U-shaped” as opposed to a closed circle so that, again, cables could simply be laid in instead of fed through the inlets which don’t line up with the connectors. This would save a tremendous amount of time.
  4. AC Spring-loaded Connectors: these are the absolute worst. Every AC connection I’ve ever made has used screw terminals to insure a quality connection. I don’t know why I assumed this would be the case here. The fact that you are already wrestling with 6AWG cable trying to feed connectors that aren’t in-line with their corresponding inlets makes it hard enough - now you have a screwdriver jammed into a slot just in front of the hole you are trying to feed the thick wire into without it becoming frayed. This just seems like an obviously terrible design decision that could easily and cheaply be changed.
  5. Configuration: I purchased the $70 USB cable to connect my GX device (Raspberry PI) to the VE.Bus port. Unfortunately, I stupidly assumed I would be able to use my Victron Connect App through the GX device to setup the MP2 which, of course, you cannot. So I went to my backup plan - an admittedly old Macbook Pro running MacOS 10.13 High Sierra. This is the latest OS that the machine will run. I tried downloading and running VEConfigure through Wine but received the message that VEConfigure is not supported on “my version of Windows”. So I go back and dig around on the Victron site and find a depcecated version of Victron Connect. It installs fine but unfortunately for me, I updated the MP2 firmware using VRM and this firmware is not backwards compatible with the older VC app. Do I need to go buy a PC to configure this thing??
  6. Battery Connection: the unit should be able to pass AC power without a battery installed. This would make sense because if you are, for instance, replacing a lead-acid battery, you would want to be able to power the rest of the RV while you are completing the DC wiring on the new battery bank. I had reached a stopping point and had completed the AC wiring but not yet finished the battery hookups. Unfortunately, the unit wouldn’t function without a battery being installed so I quickly wired one up so the rest of the RV could function (refrigerator was my main concern). If I need to replace or otherwise disconnect the batteries, does this mean I’m without power?

Rant over.

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1-4 can you add pictures please?

5 - it’s not Victrons fault that your Mac is too old.
It never was and probably never will be possible to configure a VE.Bus device via VC-R.

6 - It’s a battery inverter so it needs a battery.
You could install a bypass switch for that or you just switch off the system for a while.

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  1. Its hard to tell because the picture is taken from a slightly elevated position. Imagine the wire is coming in from the oval shaped inlet so the lug is angled upward and cannot be placed over the stud without contacting the green multipurpose headers. There are two ways to handle this: you grab the wire and twist it as much as you can to angle it down and under the headers or you push the wire against the headers and watch them flex inward until you can get the eye over the stud. Alternatively, you remove the oval inlet altogether and manipulating the wire becomes much easier to the point where this isn’t a concern.
  2. There is no need for the inlet holes since this area is not otherwise protected from water. To make it finger-safe, you could simply create “U-shaped” inlets with a matching upside down U-shaped panel that could slide into place before reattaching the main body cover for the wiring. The AC inputs already have strain reliefs installed.
  3. You can see clearly on the picture that the wire inlets/cutouts for AC-IN and the AC-OUT 2 do not line up with their corresponding headers. Moreover, the AC-IN cutout is just barely large enough to fit 6/4 SOOW wire without removing the outer jacketing and feeding the individual shielded conductors in but if the wire is being bent at all, forget about it. In my case, there was physically no way to feed the wire in.
  4. Again, U-shaped cutouts would be much, much simpler to work with and not seemingly compromise the safety of the unit. (Sorry, responded to the wrong bullet. The spring clips are difficult to set. The screwdriver port directly blocks the wire connection making it difficult. A screw terminal would be much better. Someone may disagree and I’d love to hear the counter argument.)
  5. There is absolutely no reason that a Mac running 10.13 shouldn’t be capable configuring a Multiplus II. Full stop. And I’m not sure what you mean by “VC-R”. The Mac was connected to the MP2 using Victron’s Mk3 USB adapter. I can’t make it any more straight forward.
  6. This isn’t a solution. There is no reason the transfer switch can’t stay engaged while it is connected to AC power, with or without a battery. The unit should be capable of feeding AC power even if it is off. Why wouldn’t I want that? If the only solution is wiring this in parallel then that should be more clear in their own wiring schematic, which is what I followed. That is, BTW, not such an easy task when working with gauges this large and involves purchasing larger breaker enclosures, splices, etc. on the front-end of the project. I get it - you live and learn. But my complaint is still a valid one.
4

Regarding the AC cabling, have you seen how the professionals do it? They basically put an S bend into the wires. Feed it in so the jacket extends only minimally after the gland, bend it back on itself, and then bend once again forwards before you go into the terminals. That gives you the flexibility and the slack you need.

5

I should have probably watched more youtube videos before attempting this. I don’t know why I didn’t consider the binding mechanism when I was planning everything else out - I assumed it was a screw terminal like the terminals on the other Victron stuff I have.

I’ll see if I can find what you are referencing. I still think that the spring-loaded binding clips are unnecessarily cumbersome. Slack or not, you are required to have a screwdriver implanted in the terminal to raise the clip which makes feeding the wire into the connector more difficult to see and handle. In my case, the unit was already installed so was limited on the angle in which I could work on it. The screwdriver is in the way. Its completely possible I’m just not good at this and there is some engineering reason that these terminals are used. But in the moment, I couldn’t think of one.

6

In general, the engineering reason for spring-loaded terminals is that screw terminals can get loose over time due to thermal cycling. OTOH, my Multiplus 3000/48 do have screw terminals, and aligned holes in the case, and some slot/hole intermediate where the battery cables go, so there is variance in Victron products in that regard, too.
Also, yes, watch some youtube, there’s a number of electricians on there to learn from. That definitely improved my work from “might not burn the house down” to “easier to install and adapt in the future, and not completely embarrassing to look at”.

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I think I’m regretting the Multiplus. I’ve got everything wired up finally but am dealing with the dreaded chronic GFCI trip. I’ve tried everything but the GFCI hates the Multiplus. Never had this problem with the old setup so whatever current leakage was present, the GFCI handled just fine.