Further to my previous topic on replacing a dud Delios inverter, I have been doing my layout on CAD. The Multiplus 11 Inverter and 450/100 MPPT are planned to be on the wall at about head height. All the DC cables 50 mm2 will be coming down into the Lynx distributor which is below them so keeping them short and avoiding any bends where possible. Problem I have got is with the battery leads, the battery is on the floor so terminals coming up to the Lynx would need to go round the top to the entry point on the Lynx. Is there a way of using the terminals on the ends of the Lynx so I do not have to bend the battery cable which is also 50mm2, and would cause quite a big loop. I naively thought there might be a right angled Lynx that could be joined to the standard Lynx but does not seem to be one, I am sure this issue is not unique so how have others solved it?. I have seen MRBF terminals in an American video but I am not sure if this is the way to do it and they are not listed by Victron so probably not approved. I also need a way of monitoring the battery parameters so charging and discharging can be controlled so I thought the Lynx shunt might serve both purposes but do not think so. So far my thinking would be a DIY right angled pair of bus bars to give me the solution but I would rather have a proven method,
I use them and have heat shrink that fits over. I recently had to modified someonessl so the picture below is mid modification and set up -didn’t cut the inverter cables so there is a loop- skip that part. i feel like they may change their minds again.
We have also made our own bends with bus bar. Its a mission though.
You can also mount it terminals up and have the batteries coming in from the side (supported near entry though, so some cable tray)
There is also other bus bar from victron a 6 way one that has entry from both sides, however it is not in a neat one box package like the lynx.
Many thanks to you for that.
My proposed layout would have the distributor the other way around to your example photo so cables came into the top and use the opposite terminals to your example.
I have since found out that Victron have a pair of dual terminal studs black and red which might work.Datasheet-Dual-terminal-stud-M8-EN.pdf
I will also want to incorporate SOC for the battery not sure best way to do this. Cheapest option seems to be the smart shunt which, could I also use to “turn the corner”?
Belated seasons greetings.
Dafydd
I can’t see the photos for some reason. Some people have linked the Lynx modules by connecting them with appropriate wire, usually very thick. I don’t know if this would work for the OP.
I have read that MRBFs are good for 12v and possibly 24v systems but not for 48v or above.
If you click on summary in LX reply the photo will be revealed. Thanks for the info re the MRBF.
Dafydd
Sure. With a decent size cable that matches the lynx copper size will work. And the postive link the same. Cable routing a 2x can be done one on each side if a tight bend is necessary (will be a bit more awkward with it off the other end but can be done.) we have modded the cover a few times its not likely there will need to be a warranty claim on the Power In- maybe not mod the Distributor as it has electronics.
Many thank sall I have drawn it out on the CAD and I can use the protruding bus bar side side (rather than the stud side) and the Lynx distributor would be upside down.
The battery cables can then come up direct into the Lynx.
It is an awkward layout as I am restricted by where the armoured cables for both the DC and AC come in as they suited the previous inverter.
The MultiPlus is going to be on the left of the wall and MPPT on the right. Ideally I would have liked them to be other way round but the outbuilding that houses the gear has sloping ceiling.
I have to leave 300mm top and bottom of the MPPT for the air space so have no choice.
A legacy of the previous inverter is that I have a energy meter ET 112 with RS485 port which I thought I could use. But where would I connect it to?. Presumably on the Cerbo GX.
The Victron schematic (appended) shows a connection to the MultiPlus 11 from a CT but there is no obvious connection on the photos of the inverter but then there is no Cerbo GX on the schematic.
Regards
Dafydd
Yes. The ET victron manual describes what and how. The CT depicted is not in the box with the inverter.
The inverter will connect to the CAN on the Cerbo. And the cerbo powers from the DC.
The MPPT definitely needs the vertical space and the MP2 100mm to the sides. You could use 35mm² on the mppt it is more than sufficient if it allows more wiggle room.
If there is going to be a pocket where the heat accumulates consider vents or fans to move it out of there.
Thanks again, did not know there was a manual for ET 112 by Victron. They are so encompassing, The best option is the 2.1.2 example is a similar layout to what was previously that will record grid in and export as it did previously.
Will need to wire in an USB end or get an adapter like this Waveshare Industrial USB TO RS485 Bidirectional Converter Onboard Original CH343G Multi-Protection Circuits: Amazon.co.uk: Computers & Accessories
It is a bit long at 53 mm the Victron cable seems to be a standard USB cable with bared ends so maybe I don’t need the electronics of the Waveshare adapter.
Yes I noted that I can use a 35mm cable I’ll do that particularly if I get cables made up to size.
I am not sure if I need a battery isolator on the Lynx as there is an electronic switch, and pull out (Mersen I think they are called) fuses on the battery itself.
Not had any of the gear yet I hope it gets despatched this week. Will need a few other bits and pieces as well.
My next challenge is work out how to lift the unit onto the bracket at 42kg it is a heavy piece of kit. The previous inverter was about 34 kg and we lifted that up by making a cradle for the bottom and jacked it up with timber sections and hydraulic car jacks.
Think I need a safer method this time as it was a bit nerve racking doing the Delios. Maybe look for an inflatable air bag or similar. Any suggestion?
Dafydd
Yeah. Not really. For most of our installations it is the old grunt’n’lift method.
No you won’t if the batteries themselves are fused.
I’ve had to get creative with some of my wiring in the past. The suggestion of using a busbar is probably where I would have started. I would find a length of copper flat bar that is suitably sized. That can connect to the normal position on the Lynx Distributor and stick out far enough to allow your cable to connect without having to make the bend.
Also, don’t think in only two dimensions. If you mount the Lynx Distributor 1” away from the wall with spacers you can run the cable under it and avoid going around it. You still have the issue of getting the cable into the opening. The trick with the copper flat bar isn’t going to work very well as the positive and negative studs are on top of each other. The way to get around that is to use different length copper flat bar. Not an ideal solution, but it shows that there are multiple ways to make the wiring work.
Thanks Jim for the reply.
Most of the ancillaries are mounted on a big board beneath the inverter and MPPT which will be fixed to a blockwork wall.
That is spaced off the wall by 9 mm I can run some thinner cables behind that but lifting the distributor does give me more options particularly with the AC wiring.
I had though I had cracked it by using a smart shunt as the “extension”.
But then another little hurdle crops up the 10mm bolts do nicely for the distributor and shunt but my factory fitted lug on my battery is 8mm.
I have not studied the surface area of a 10mm lug to compare with an 8mm (not got one) to see if it would make a difference if I drilled out the 8mm lug to 10mm.
Strange when all the battery fixings are 8 mm that Victron have mixed the sizes. There must be a good reason to go from an 8mm hole distributor to a 10mm one.
Dafydd
I am getting too old for that weight some many years have passed since I was able to put a 1cwt bag (50kg) of cement on the back seat of a car.
I’ll come up with something I usually do.
Dafydd
Apparently when Victron introduced the 1000A Lynx BMS they discovered the m8 end connections weren’t sufficient, therefore the m10 lynx components were born….however what was going on with the m10 units before 40th week of 2023? They must have made a running change to almost double fastening torque on the interconnection, doesnt give warm feelings about the m10s made prior to that date.
“M8 Model: 14Nm
M10 Model: 33Nm (17Nm for units with a serial number before HQ2340XXXX)”
And now m8 lynx power ins and distributors etc are getting hard to find as they are no longer in production, all m10s going forward.
Thank you that is most interesting thought there would be a reason somewhere. Got another query think I wll start another thread.
On a side note the bolt doesn’t carry the amps… Just saying.
And the likelihood of your bus bar experiencing 1000Amps in your set up is unlikely.
What I was thinking was, though I did not express it as such. drilling out the 8mm hole in the lug to 10 mm may reduce the surface area contact compared to a 10mm lug. But a 10mm lug dimensions may be same size as an 8 mm lug. Guess there will be variation from maufacturer to manufacturer anyway. Joints are always the weak point in any system. Bet there will be someone somewhere that has reaserched this.
Yeah. Resistance through mating surfaces… Etc. did a short study on it.
Yeah. Surface area and contact is the key.
The problem usually begins where it was an 8mm hole lug and someone drilled it out vs buying the 10mm hole lug in the beginning. 50cent problems becoming more costly.
I have found more of an issue with the the way crimped lugs are done on ends on cables. (being tied between bad crimps incorrect lug size use and crimping on heat shrink insulation.)
Your other option for space is moving out in a 3d fashion.
So create a second face to work on with a frame or something. If that is an option for you.
The 8 mm lug on my BMZ battery leads is made in the factory, the battery came with the 50 mm2 cable already fitted. I am reluctant to cut it off and fit a 10mm lug as my crimp will not be as good as the factory one. When I get all the stuff thats on order I will have better idea of how to put it all together. Doing it on the CAD is one thing, doing it for real is another. But CAD though gives me a good starting point. I am not conversant with 3D cad that would be more useful.
I believe the reason for the larger stud is that there will be heavier cable used. 10mm can handle more weight than 8mm.
I tend to use the smallest stud possible to ensure I have the most surface contact.