Connecting 2 SMA inverters to internet

[Sunburner]

I recently commissioned a second, 12 kW grid-tied system which has 2 SMA 5.0 inverters. I want to connect them via ethernet to the internet for monitoring on Sunny Portal.

My question is how best to connect these 2 inverters? Each inverter has 2 ethernet network ports, A and B. Can I daisy-chain a cable from inverter #1, port B to inverter #2 port A and then from Inverter #2 port B to my router (or in this case a Ubiquity Litebeam ethernet bridge)? Or should I run a line from each inverter to a "Y", or switch, which connects to the router?

My installer in not too strong on the web connect side but suggested the daisy-chain method. The SMA manual doesn't address this.

Any suggestions?

Thanks in advance

[Mike90250]

I would use a 4 port router (wireless or not) and connect 1 ethernet from each inverter to a port on the router, and then connect the router to the internet

[sensij]

Yeah, what Mike90250 said. Running them both to a switch that is connected to your router should be OK too. You can daisy chain them, but then you'll need a cluster controller between the chain and your router.

http://files.sma.de/dl/7680/Speedwire-TI-en-11.pdf

[Sunburner]

Thanks Mike90250 and sensij for the helpful responses.

The SMA cluster controller @ $1,000+ seems like overkill for my purposes but the manual is very helpful. Would something as simple as an rj45 2-way splitter work or would I be better off with a router?

For a little more information, I am connecting the inverters, located on my barn, via a PoE injector to a Ubiquity Litebeam 5AC Gen2 point-to-point station aimed at its paired AP some distance away at my home, which in turn is connected via ethernet to my Time Capsule router, set to addressing by DHCP. Would there be a problem adding a router on the inverter end?

[sensij]

Thanks Mike90250 and sensij for the helpful responses.

The SMA cluster controller @ $1,000+ seems like overkill for my purposes but the manual is very helpful. Would something as simple as an rj45 2-way splitter work or would I be better off with a router?

...
Would there be a problem adding a router on the inverter end?

A simple small ethernet switch should be fine, <$20. If by "splitter" you mean a wiring adapter that just mechanically creates two jacks from one plug (like a phone line splitter), I don't think that will work.

[Mike90250]

You need something "smart" that can assign IP addresses. A simple "dual wired jack" will not be very successful. Router or switch would work. Hub or single/dual splitter, not likely.. I use a Alpha wireless router and get about 300' through trees from my power shed to bedroom.

[Sunburner]

Thanks again guys. The splitter I was referring to is a simple "wye" and I see now that it won't work.

So something like the TP-Link 5-Port Fast Ethernet Unmanaged Switch | Plug and Play | Desktop on Amazon at $11.99 would work? Cheaper than a router but will it do as good a job? I don't need it for anything other than monitoring these inverters.

I hope you'll excuse my ignorance about networking - I've been struggling mightily to configure these Litebeams - but is there any problem having 2 routers negotiating with each other on the same line? My inverters will ultimately be linked to my home router (Time Capsule) for internet connection. The distance between my solar array and my home is about 600 meters. I'm using meter aggregation to apply solar production from my barn meter to my home meter.

[ImInPhxAZ]

Yep, all you need is a small cheap unmanaged switch. That will do the trick. I would recommend against two routers in a home environment,

[Sunburner]

Great! Thanks ImInPhxAZ and others for your advice.

[solarix]

I have done what the OP described and it works fine. Just daisy chain the inverters together using the A & B ports - that's why there are two of them. Call the SMA techline (but they only talk to installers now) - they are more than happy to help you with the configuration. If I remember right, you just have to make sure both inverters use the same password.

[Sunburner]

So here's an update.

I went ahead and bought a TP-Link TL-SG105 unmanaged 5-port switch. Turns out, as solarix says, it's not necessary and daisy chaining from one inverter to the other with one ethernet line out works just as well. But the switch allows me to jack in with my laptop, or otherwise have additional devices if needed so it wasn't a wasted investment. I'm able to login to the inverters and configure as needed.

Unfortunately, my SMA inverters are giving a "faulty Webconnect" communication error and I am not able to access them beyond the switch.The switch has an amber light at the inverter plugs, indicating a slow connection, but my laptop is green. Maybe it has to do with my ethernet bridge using Ubiquity Litebeam AC5 Gen 2 radios. I get a good connection with my laptop so I'm not sure why the inverters are having problems. More troubleshooting ahead.

[sensij]

So here's an update.

I went ahead and bought a TP-Link TL-SG105 unmanaged 5-port switch. Turns out, as solarix says, it's not necessary and daisy chaining from one inverter to the other with one ethernet line out works just as well. But the switch allows me to jack in with my laptop, or otherwise have additional devices if needed so it wasn't a wasted investment. I'm able to login to the inverters and configure as needed.

Unfortunately, my SMA inverters are giving a "faulty Webconnect" communication error and I am not able to access them beyond the switch.The switch has an amber light at the inverter plugs, indicating a slow connection, but my laptop is green. Maybe it has to do with my ethernet bridge using Ubiquity Litebeam AC5 Gen 2 radios. I get a good connection with my laptop so I'm not sure why the inverters are having problems. More troubleshooting ahead.

The amber light probably indicates they are connecting at "fast ethernet" (10/100 mbps) speed, rather than "gigabit" (1000 mpbs). That is to be expected, there is no reason for the inverters to require or be built with gigabit network interfaces. The Ubiquity connection is probably to blame, for one reason or another.

[Sunburner]

The amber light probably indicates they are connecting at "fast ethernet" (10/100 mbps) speed, rather than "gigabit" (1000 mpbs). That is to be expected, there is no reason for the inverters to require or be built with gigabit network interfaces. The Ubiquity connection is probably to blame, for one reason or another.

Thanks sensji. You're correct about the indicator lights. I wonder why I can get a good, gigabit connection with my computer but none at all with the inverters? Maybe a question for Ubiquity. Or SMA.

[sensij]

Thanks sensji. You're correct about the indicator lights. I wonder why I can get a good, gigabit connection with my computer but none at all with the inverters? Maybe a question for Ubiquity. Or SMA.

The ethernet adapters inside the SMA Webconnect unit are probably not designed to support gigabit, since there is no reason for that kind of speed in this application. The 10/100 connection is all they are capable of, and the amber light does not indicate anything is wrong. That is more than enough speed for the data you are sending. Your laptop has an ethernet card that supports gigabit, so you get the faster connection with it.

In other words, your challenges accessing them on the other side of the Ubiquity bridge have nothing to do with their connection speed/quality to the switch.