automatikdonn
Becoming Offgrid
Hopefully it fails harmlessly, even better would be a PID loop that checks the voltage on the grid side terminals and shuts down if nominal voltages are exceed.
EG4 18KPV - What not to do in parallel
- Thread starter automatikdonn
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Hopefully it fails harmlessly, even better would be a PID loop that checks the voltage on the grid side terminals and shuts down if nominal voltages are exceed.
ksmithaz1
Solar / EV Junkie
If you unplug the cable the systems get pissed and drop into standby. At least they used to I haven't tried it in a while.
This is killing me. If I hook the interconnect cable up to a poe ethernet hub and the inverters do not work properly it's EG4's fault, they should have thought of that after all. I cross wire the phases, sh*t goes boom, it's EG4's fault. I smash the thing with a sledgehammer sparks fly, and it's EG4's fault. I don't buy it. It is not the responsibility of a manufacturer to make sure you wire their product correctly. If the instructions are not clear it is your responsibility to get it right, if you chose to just guess or grab whatever is handy and staple it together anything that goes wrong is on you.
You can blame the dog, the manual, the engineering, but the bottom line remains that if you don't wire something properly it may not work properly. If you blew up stuff because of this, it obviously was not tested by the installer, so not only did the installer wire it wrong but they did not test the proper operation of the equipment. Again apparently this is EG4's fault. I wired it wrong and I did not test normal operation things did not work properly, equipment was fried, but it it isn't my fault because the manual was not explicit about a cable pinout and I didn't bother to verify a darn thing on a device with lethal voltages present.
Sure thing. Not my fault, point fingers and complain about the engineering.
I can assure you my system was turned on with no load and inputs and outputs were measured before anything was connected. I tested shutting inputs / outputs and switches off/on to make sure things were as expected under all of the various operating conditions I engineered it for. If you did not do this shame on you. These installs are not trivial, there is a lot of stuff going on. You need to pay effing attention.
automatikdonn
Becoming Offgrid
He did try to test. When the very first test was executed, 400v were sent to the appliances in the home.
I was called after that.
No inverter should be sending 400v back towards the grid for any reason
Unintentional islanding clearly doesn't work
(Which includes human error)
If the parallel cable was this important, then it should have been called out in the manual. It is in the upstream Luxpower manual...
At the end of the day its a flaw. All products have flaws. Blaming the installer however is just straight up not correct.
ksmithaz1
Solar / EV Junkie
So it was TESTED with a live load the first time. Oops, but on that front kudos: it failed the test and the problem has now been figured out, albeit with some unexpected equipment damage.
Something about always and never comes to mind. Easy to say. Should be addressed for the future if possible.
Implying the issue was not caused because it was improperly wired/installed, which is clearly what caused the problem. Had it been wired properly to start with this thread would not exist. A miswire creating a cascade failure condition is not exactly unheard of. Had I done this I would have owned it, not blamed it on anything else, I put the wrong cable in, my fault. I have cooked a data port or two in a similar fashion on some expensive equipment over the last 45 years. I would also have reported it to be addressed by the manufacturer, to help out the next idiot, but it's still my fault.
automatikdonn
Becoming Offgrid
There was no way for the installer to know this kind of event would occur. There was no way to know that it wasn't wired correctly.
It was utterly undocumented. It just said plug in an RJ45 cable. No mention of a pinout or wire type. If someone doesn't work with these types of cables every day, looking at the pinout of the connector is unlikely with a commercial off the shelf (Belkin) cable.
automatikdonn
Becoming Offgrid
(Two posts because two different points)
How do you explain the inverters not shutting down to the voltage being out of range and out of phase? Is that the installers fault too?
Dave911
Solar Enthusiast
I dont buy your arguments. If you connected a router to your laptop with a crossover cable and your laptop caught on fire, you'd say thats unacceptable. This is a design or firmware problem. EG Jarret doesnt say whats going on with the sync signals. I dont know the solution. But if they are running raw sync signals over an Ethernet cable, thats a problem. Ethernet cables are Ethernet cables and not intended for anything other than digital communications. Its likely that Ethernet cables were chosen because they are dirt cheap. Ironically, inexpensive SRNE ASP inverters use a VGA type cable for parallel synchronization. Maybe that was a better design choice. Yet the inverter is less than half the price of the 18kpv. Hmmm....
Luxpower screwed up here.
marionw
Solar Addict
What is the difference between a cat5 cable and a 15 pin VGA other than the number of wires. Pretty hard to decide one is better than the other without knowing exactly what type of signaling is used. Might only be 5 volt logic level square wave timing signals
Dave911
Solar Enthusiast
It does appear that using Ethernet cables was a bad choice. I find it interesting that a much cheaper inverter, uses a more expensive interface. A good question is why. I suspect that SRNE has a very good reason to do so. Otherwise they would be using cheap RJ45 cables as well.
zanydroid
Solar Wizard
Might blow folks minds here that Cat cable is used for professional analog video transmission
Cat6 has 250 MHz of bandwidth, I believe that is per pair and there are 4 of those.
NTSC Composite video is single digit Mhz over one pair
Cat6 has 250 MHz of bandwidth, I believe that is per pair and there are 4 of those.
NTSC Composite video is single digit Mhz over one pair
Hedges
I See Electromagnetic Fields!
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No, it was tested with no loads.
It was tested by feeding it from the grid (house wiring to "Grid" input).
Probably did not have a combiner box, only two breakers in a panel feeding two inverters. Or maybe two taps off a wire?
If installer had shut off all breakers to other circuit from the house before cutting power to the house, it wouldn't have had a chance to blow up appliances.
Maybe he was then going to check Load terminals, if intended to do batteryless backup.
With grid power disconnected, instead of cutting off backfeed per UL 1741 anti-islanding, it proceeded to backfeed ~400V with enough power to kill appliances.
BIG FAIL ON THE MANUFACTURER'S PART.
YOU NEVER, EVER BACKFEED POWER INTO THE GRID WHEN THE GRID IS DOWN.
NO MATTER WHAT DATA CABLES ARE CONNECTED, OR WHAT IS ON "GEN" OR "LOAD" TERMINALS.
THAT VIOLATES UL LISTING AND COULD HAVE ELECTROCUTED A LINEMAN.
I used to have a some of those cable for a PBX system-- BRI cards needed them. We used the label maker to mark each end and the middle with "BRI Crossover Cable" so they didn't get re-used for the wrong thing.
Brucey
Solar Wizard
Yes this seems like Boeing who loves to blame "pilot error" versus taking accountability for garbage management putting profits ahead of human lives.
labeeman
Solar Enthusiast
Rat chewing on the cable could cross them like it was a cross over cable not likely but could happen.
marionw
Solar Addict
That may be true for video but for the ethernet protocol cat5 and cat6 support over 1ghz of data transmission
marionw
Solar Addict
Keep in mind there are a number of manufacturers as I suspect this firmware is used in a number of "clone" inverters.
Until every parallel capable inverter (regardless of whether it uses cat5 or a vga cable) is tested this is probably an issue for more than just the EG4 18kpv
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
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CATx cables get used for Ethernet, with transformer-isolating magnetics in the jack and layers of error detection, correction, retry in software.
They get used with lower level hardware and maybe firmware/software but lacking the higher levels, e.g. for Philips ProfiNet, which can be used for keep-alive signal and shutdown on fault. I dealt with EMI/EMC failures where kV noise injected on power lines didn't affect other communications but triggered shutdown. Higher quality shielded cables were required for the longer runs.
I've also seen these CATx RJ-45 cables used between boxes where there is no transformer isolation. That was the case for a KVM extender, which showed image distortion and shut down during bulk current injection tests, a clamp transformer which injects modulated 10V common mode noise.
SMA uses RJ-45 cables for both their bus between Sunny Island battery inverters (similar communications and sync signals), also for communications from SI to older Sunny Boy battery inverters, switching between UL-1741 on-grid and "island" off-grid modes, and to monitoring hardware. Those are not transformer isolated, and both (I think) run 1200 baud. Newer SMA models use "SpeedWire" which is Ethernet so isolated.
zanydroid
Solar Wizard
I did say they have 4 pairs at 250 mhz each. All of those are used together for simultaneous tx/RX for 1Gb through 10Gb. The TX/RX combining being done via a hybrid cancellation circuit
automatikdonn
Becoming Offgrid
I don't know that the type of cable or connector is really the issue though. The inverter should always trip offline when volatge is detected on the grid side terminals that are out of range.
ksmithaz1
Solar / EV Junkie
I agree with this, and apparently the somewhat aggressive testing found the installation error with some thankfully, relatively minor consequences. I will not dispute that the error handling for the mis-wiring should be handled better, as this mis-wiring created a hazardous output condition, but at the end of the day it was mis-wired. There is no way anyone could know this event would occur unless this exact scenario was tested beforehand thus I'm not sure what this has to do with wiring something wrong.
I strongly dis-agree with this. A "professional" installer should not make any assumptions about a cable that synchronizes two high voltage devices. In particular it should be obvious this was not any kind of a standard networking interconnect, nor was it labeled as such. To state otherwise is disengenous at best. As much as all the folks in this thread are arguing about making assumptions about RJ-45 cables, this discussion shows this to be a fallacy at the outset. Further the provided battery communication cable is non-standard.
I had 5 inverters in parallel before I got the EG's I have. They used a 15-pin HD-DSUB for sync/comm. Most 15-pin HD cables have a key pin, they only wire thru 14 of the 15-pins, and I needed a 10 footer for one of the runs instead of the supplied 7 footers. It took me three tries to obtain a 15-15 10 foot cable, and I actually took a meter to the cables before I hooked it all up. It is likely the missing pin would not have caused a problem, I doubt they were using all the pins, none the less, the answer from PowMr was to only use the supplied cable. There was nothing in the manual about the pin-outs, and if something failed or blew up because of it that would be on me. 100% my fault!
This is no different than if the cable was wired to color coded screw terminals, and you screwed it up and cross-wired some of the pins, and something went poof. The fact that the connection was an RJ-45 connector is not relevant. A professional should never substitute wiring or cabling in a device without understanding what they are doing and the potential ramifications. That's why you get paid to do it, that is what makes you a professional. If you are taking money, you should damn sure have a basic understanding of the product you are installing, and if you don't you ASK FIRST. You either know or you find out what you don't know. I consider the professional installer negligent (not malicious). The issue caused by the negligence is ancillary.
ksmithaz1
Solar / EV Junkie
So you are saying the device does not disconnect when wired properly? This is where the argument falls over. The inverter will *always* trip offline when it is properly wired. Do you dispute this? I mean it may not work properly if I break out the '45 and drop a little lead in the cabinet. Saying a device should always do the right thing when you screw up the wiring is disengenuous.
ksmithaz1
Solar / EV Junkie
To the point manufacturer of the integrated components and IC's used to build these systems, generally provide a core firmware that is provided to the OEM's under an NDA. The OEM's then modify and expand on that firmware as required to work it into the desired needs of the full system. Sadly many manufacturers do very little in the way of testing, updating, and correcting past the initial release.
automatikdonn
Becoming Offgrid
If you do use the right cable and one (or many) of the pins goes bad - it's very likely to experience the exact same issue. Can Bus is up, but the parallel signals aren't.
The way I interpert what you are saying is the installer bear's 100% responsibility for this issue. If that isn't what you are saying, then please make that clear. Forums can sometimes be difficult to convey intent.
I had said this earlier, but I can't find it.
I think EG4 bear's the brunt of this, but are not 100% responsible.
I would put it at maybe 80/20
I'm not arguing that the installer didn't make a mistake - I am arguing that these inverters in parallel operate outside of UL1741. I have already posted the specifics a couple times, so I am not doing it again.
The inverters should trip offline when the freaking display reads 387v on the grid input - no excuses. I don't care if it's miswired, the inverter is GENERATING this voltage and should not.
sunshine_eggo
Happy Breffast!
I am. He used an RJ45 cable in accordance with the installation manual published at the time. Had he been working to the Lux manual or the current EG4 manual, I would say it's his fault, but it would still bring into question the suitability of this unit for its intended use with this failure mode and place some blame on EG4/Lux.
Quattrohead
Solar Wizard
I can count on the fingers of one hand bad network cables in my life and there must have been tens of thousands that I have installed.
I even had one that must have been plugged and unplugged many hundreds if not thousands of times because the user wanted to send RS232 data from a CAD PC to one CNC machine or the other. (Ewww I know RS232 over an old network connection)
Yes the inverter could and should have handled the situation better if it knew exactly what was going on, but it didn't because the installer cocked up the install. Again I ask where is the installer in all of this?
I even had one that must have been plugged and unplugged many hundreds if not thousands of times because the user wanted to send RS232 data from a CAD PC to one CNC machine or the other. (Ewww I know RS232 over an old network connection)
Yes the inverter could and should have handled the situation better if it knew exactly what was going on, but it didn't because the installer cocked up the install. Again I ask where is the installer in all of this?
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