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  1. Like
    ___ got a reaction from Basil Katakuzinos in Kodak inverter   
    Oh dear, some of those look like Voltronics too. So either its a major rebadger... or a cloner.
    I'm just wondering about the Kodak name. Kodak went into chapter 11 Bankruptcy in 2012, but they technically emerged from it (still struggling), so the brand is still around. They are now merely a shell who licenses their brand to partners. For example, they had a bitcoin miner at CES in 2018, which was apparently considered a scam of some sort. Then there is Kodak Power Distribution who supposedly makes these things, but their http site has a stock shopify page on it, and the https one has an expired certificate.
    Basically... I suspect these things are made by someone in China and being dumped here... but I may be wrong if someone can find more info of course.
  2. Like
    ___ got a reaction from Basil Katakuzinos in Installing a Ziehl 101E Anti-Islanding Relay (SA Settings)   
    When combined with a Victron inverter, you need only one contactor. The NRS097 requirement is that you must have two relays in series and that a single failure must not break the system (ie there must be some redundancy). The Multi already has one such relay and LOM-detection (loss of mains). Adding the Ziehl with just one relay is sufficient to tick the second box.
  3. Like
    ___ got a reaction from Sarel in Another Blue install   
    Perfectly fine to be in the same vicinity, where they terminate. Nobody is that OCD.... okay... few people are that OCD 🙂
  4. Like
    ___ got a reaction from Kalito in Panel Installation Ideas   
    I have two frames made out of 40x40 angle iron. That stuff is insanely useful. The important thing is to treat them with the right kind of paint/covering. My one frame is holding up very well. The other one is rusting and I plan on replacing it with an aluminium frame.
  5. Haha
    ___ got a reaction from WJP in My new Victron install.   
    You sure? I seem to recall the battery with the open top link port is the master, ie the top?
    Edit: Oh hang on, I'm looking at the wrong picture. The "console" plugged tipped me off... 🙂
    I would move the master to the top (American politics be damned, that just seems right), and there is enough slack in the red battery cable to move that to the top module as well (so you get proper cross-link cancelling out of cable resistance).
  6. Like
    ___ got a reaction from 87 Dream in Axpert with Victron MPPT - does it make sense and how would it work?   
    Right... a lot to say here 🙂
    First on the how it would work. Since the Axpert doesn't do any state of charge measurement of its own and only looks at voltage, it really doesn't matter too much if you use an external MPPT to get the energy into the battery. I'm not sure how it would interact with the various "programs" of the inverter, I mean there are thing like SBU (solar before utility) where I assume the presence of solar power affects how it works, so I assume some changes will be required, but overall I suspect it will just work.
    There are some things to know about that test.
    The first is that the values returned by the hardware itself was used, so it did not account for calibration differences. The slight bit by which either charger outperformed the other was too small to crown either one a winner. Ideally one should have used a third-party measurement, eg a separate battery monitor, for both tests.
    The second is that it didn't test the speed of tracking, ie how fast the tracker finds a new maximum after conditions change. The Victron charger tracks faster, that is true, but in the South African context I'm not sure if that will provide significant additional generation, given that our cloud scenario is usually somewhat all or nothing 🙂
    The third is that it benchmarked one of the less expensive Victron MPPTs. There is something called an overcurrent event, that is when conditions change suddenly and the current value rises sharply and exceeds the limit of the charger before the control loop can pull it back. The cheaper controllers (which also includes the Axpert) shuts down and restarts from zero. The higher-end Victrons have a hardware current clamp and avoids this restart. So already this comparison is not helpful to the chargers you're considering.
    Fourth, I think what your installer is aiming for is the lower cable losses. The Axpert has a fairly narrow power band between 80V and 135V. Even though it is rated to 145V, it starts to derate. This means that for an Axpert the optimum setup is 3 x 60-cell modules in series. 4-wide the open circuit voltage becomes a tad too high, and with 72-cell modules you have that problem even earlier (max 2-series, at 3-series you're pushing 150V on a cold morning). Since most of the affordable and larger modules are now 300W and above, even the 150V chargers from Victron (no derating, but they also shut down above 145V) are somewhat limiting. This means thicker cables, more of them, and because of the narrow voltage band, it does mean a slightly shorter solar day. So I think this is the big item he is aiming for: With a 250V charger you'll get a bit more juice out of it.
  7. Like
    ___ got a reaction from CCC Telecom in Installing a Ziehl 101E Anti-Islanding Relay (SA Settings)   
    When combined with a Victron inverter, you need only one contactor. The NRS097 requirement is that you must have two relays in series and that a single failure must not break the system (ie there must be some redundancy). The Multi already has one such relay and LOM-detection (loss of mains). Adding the Ziehl with just one relay is sufficient to tick the second box.
  8. Like
    ___ got a reaction from TJ Botten in Monitoring Pylontech batteries via WiFi   
    This is the reverse kind-of thing. I have an arduino with a canbus shield talking to a Venus-GX (in this application it is pretending to be a battery, it makes it possible to test code with all sorts of rubbish in the can frames). But you could easily reverse it and have it talk to a battery using the CAN-bus.
  9. Like
    ___ got a reaction from 2simguy in Neutral/Earth bonding relay Goodwe ES inverters   
    In my estimation the risk is low. Your neutral becomes a "hot" conductor (one might say), but if touching it causes enough current to flow to exceed 20mA-30mA, the RCD will still trip. With that said, I must still note that this would not be SANS compliant. SANS requires an islanded system to bond T and N.
    Both these are not allowed by SANS. Bridging the neutrals would probably be the lesser evil, 1) because Goodwe advises that you do this, and 2) apparently it is allowed in Australia. You won't lose the bond when there is a grid outage, but you might if your main breaker trips (which disconnects the neutral) or if you switch it off for any reason. Probably better than nothing, but not perfect.
    In my view this is the only proper way to do it, and ideally one would want the inverter itself to signal this (like the bonding relay box that's turned on by the internal relay in the Axpert). Only, I don't think the Goodwe has any way to signal such a relay.
    One potential way is to use a contactor with 2 x N/O and (at least) 1 x N/C contacts. Use the two N/O contacts to switch the grid to the inverter, and the N/C to make a bond on the output. Let the grid pull in the contactor, that is, when there is a grid outage the contactor drops out.
    The reason for actually switching the grid connection through the contactor is to mechanically interlock this operation: It would be impossible for the bond to be applied if the grid isn't also disconnected.
    Downsides to this scheme:
    1. If the voltage is out of range, but high enough to pull in the contactor, the inverter might switch to islanding mode while the bond remains unapplied.
    2. NRS097 mandates a 60 second monitoring window after the grid returns. If the voltage/frequency remains stable in this 60 seconds, the inverter will connect back to the grid. The trouble with this: When the grid returns the bonding is removed, but for another 60 seconds the output will remain floating.
    Which gets me back to my point that ideally, one would like the inverter itself to signal islanding mode in some manner.
  10. Like
    ___ got a reaction from podarok in Axpert inverters in parallel   
    Yup, the inverter will slow down its own frequency to sync with the grid frequency, If you put it in  situation where this can't be achieved, it will end up at some extreme value.
  11. Like
    ___ got a reaction from Durbanguy in Conduit through iron roof   
    I know. I made that mistake only once, way back in the day on the farm in Namibia. Dad came walking past and saw where I drilled the hole and the disappointment was palpable. Of course, given the weather, it hasn't rusted yet! (20 years later)... but the memory has remained.
    Way too far to drive just for that :-) Maybe a local store has something similar, thanks.
  12. Thanks
    ___ got a reaction from Marius De Kock in Youda's off-grid LAB   
    Yup. CAN-bus is a BUS. It's two wires running from the one end to the other, with 120Ω terminators at the ends, and many modules can connect to the CAN-H and CAN-L of this bus. There is a whole arbitration and collision avoidance protocol, and everything essentially waits for a gap and then they send their data.
    It's a bit like those old 10base2 Co-ax network cable setups (anyone remember those, or is it just me who is getting old?). Or perhaps another analogy, it's like your television RF cable... you can throw a splitter on it and add another tv at te end.
    The only thing you have to ensure is that the bus is terminated at both ends. Often there is already a terminator built into the ends (sometimes there is a DIP switch to enable/disable it), and on a short run one missing terminator usually doesn't break the bus... but it's a good idea to ensure you don't break the termination.
  13. Like
    ___ got a reaction from Marius De Kock in Youda's off-grid LAB   
    Preach it brother! Absolutely agreed.
    Yup, and unlike some of the other more commonly demanded hardware, these are not always cheap. Your options are:
    1. Rpi with a MCP2515+MCP2551 hat, probably your best bet.
    2. Same chip-combo, but with SPI header that you just wire to the relevant pins on the Rpi/Arduino.
    3. Arduino with the same chips on a shield.
    4. Same arduino setup, but run the slcand code so it shows up as a serial-can device on linux, ie the arduino becomes a usb interface to can-bus.
    5. A USB-can chip, such as the CANable or Kvaser (very costly).
    The canable would be my choice, except that it's still 30USD, so cost-wise the the hat/shield options will probably win. Aliexpress shows a few 15USD options, but there is no telling if they are any good.
    Cheap "canable" interfaces... that's what we need.
  14. Like
    ___ got a reaction from Tim003 in Fuse and Quick disconnect between Pylontech battery and Inverter   
    Why would you take the chance? But okay, you're right, I'm arguing the sensibility and you're arguing the legality... so here goes...

    That's from a draft copy of SANS-10142-1 that has the new DC bits added to it. It says you MUST have an overcurrent device in place. Does not have to be a fuse, can be a breaker, but it must be able to interrupt the full short circuit current of the the battery (which would be a very hefty breaker).
    The insurance company will smack you on the letter of the regulations. Put the damn fuse in 🙂
    What is also interesting here is how ground-faults are avoided. The cable between the battery and the protection device (fuse) must be kept as short as possible, and the positive and negative cabling up to the fuse must be kept separate. They are clearly trying to avoid fault conditions on the wrong side of the fuse. When you do this, you need a battery fuse only in the positive line, since ground faults are now unlikely (it would have to happen in the very short cable to the fuse on the positive side).
    Edit: Also note "NOTE 3", which already refers to the battery protective device, aka the BMS.
     
  15. Like
    ___ got a reaction from melvin phuti in ECU CBI Interesting device and how would one connect   
    It's essentially an internal load-shedding solution to keep your own peak consumption down, by ensuring that two high-consumption appliances are not on at the same time. Eg Stove and Geyser. These days, a function like this could be integrated into something like a geyserwise.
  16. Thanks
    ___ got a reaction from CCC Energy in Connecting a Carlo Gavazzi ET112 to Victron CCGX   
    This part often causes confusion and people wonder why that fuse is there. Let me see if I can explain.
    That neutral wire, which would normally be black in colour, carries only the current required for the electronics of the meter itself. The red wires between terminals 1 and 2, they carry the big stuff. Since that black wire only carries a few milliamps, it does not have to be a very thick wire. It can be as thin as 1.5mm^2. And under normal conditions, that would be all that is ever needed. But you have to cater for what happens under not-normal conditions, aka fault conditions.
    Under a fault condition inside the meter, that meter might be dead-shorted from either terminals 1 or 2 to neutral. It is unlikely, but you have to cater for that. In that case, you must have overcurrent protection for that thin black wire, so that the wire itself does not turn into a small heating element that burns down the house. That's what the fuse is for.
    The fuse just needs to be sized for (or smaller than) the wire. In this case something like a 5A fuse will be more than sufficient. It is less than the wire can carry, so it protects the wire, but way more than the meter will ever need to operate.
    But... you can also just leave the fuse out. But then you must size that black wire for the full current of whatever the upstream breaker is. Since this meter is usually installed right after the big 60A breaker that feeds the house, that black wire must be sized for 60A then, that is to say, it would have to be a 10mm^2. This is what I see most installers do, they just use a thick enough black wire.
  17. Like
    ___ got a reaction from CCC Energy in Mersen battery disconnect - large cables   
    I have never quite understood how you are supposed to get a cable into them. I always cut the plastic to get the cable in. Don't like it, but until someone can tell me how it is supposed to work, that is what I do.
  18. Haha
    ___ got a reaction from hoohloc in Backup ups   
    Dude... I once saw a motorcycle advertised on gumtree. Beautiful machine, almost brand new. The seller explained that his reason for selling is that apparently "Do whatever the f... you want" doesn't mean what he thinks it does.
  19. Like
    ___ got a reaction from NoordSolar in Recommend me some batteries for solar to replace existing lead acid deep cycle   
    Yeah different BMSes have different expectations of the hardware connected to them. Some BMSes get very upset and disconnect their DC protection relay/FET easily if you don't stop charging quickly after it has ordered you to do so.
    In my experience, if you keep your battery voltage BELOW the voltage where the BMS activates its protection features, and if you have a large enough battery so that constant charge current interventions is not necessary, then you don't need communications with the BMS. If anything bad happens, the BMS shuts off the power and the entire house goes dark. Oops... let's not do that again 🙂
    There is however one very useful feature that comes from BMSes that can do comms, and that is that they track SOC. If you already have another way to track SOC (eg an inverter that has this built in, or a BMV), then you don't need to use the BMS for that. SOC is always an estimate, and even the BMS gets it wrong (I have examples of use cases where a BYD battery gets it spectacularly wrong), so using your BMV-7xx is really not a bad alternative.
    But ideally you want a BMS that allows you to regulate the voltage and not constantly mess with current limits. If you just aim for 3.45V per cell, it should run like a conventional lead acid bank...
  20. Like
    ___ got a reaction from YellowTapemeasure in Youda's off-grid LAB   
    Preach it brother! Absolutely agreed.
    Yup, and unlike some of the other more commonly demanded hardware, these are not always cheap. Your options are:
    1. Rpi with a MCP2515+MCP2551 hat, probably your best bet.
    2. Same chip-combo, but with SPI header that you just wire to the relevant pins on the Rpi/Arduino.
    3. Arduino with the same chips on a shield.
    4. Same arduino setup, but run the slcand code so it shows up as a serial-can device on linux, ie the arduino becomes a usb interface to can-bus.
    5. A USB-can chip, such as the CANable or Kvaser (very costly).
    The canable would be my choice, except that it's still 30USD, so cost-wise the the hat/shield options will probably win. Aliexpress shows a few 15USD options, but there is no telling if they are any good.
    Cheap "canable" interfaces... that's what we need.
  21. Like
    ___ got a reaction from Boerseun in Mecer 1200va not opening garage door   
    I had one of those... but it broke way back in December 2012. This is what the big worm gear mechanism looked like:

    These door openers have a normal 230VAC induction motor, and as a result it will have somewhat of a start spike, generally about 5 times its nominal rating. I suspect that's the issue, it simply overloads the inverter.
    I have since thrown the remains of it away, but a it of googling indicates it has a 0.5 horsepower motor, which is just short of 400W. That would need a good 2kw kick when it starts. While many inverters (including the voltronics) can handle a 200% spike for about a second, I suspect your's is JUST a tad outdone by that motor.
    A new low-voltage motor is around 2.5k and well worth it imho.
  22. Like
    ___ got a reaction from Boerseun in 3 Phase generator connection   
    No, that's not going to work. The inverter wants to close its transfer switch and connect the input to the output. The outputs are tied together in a single phase system, but the inputs are 120 degrees apart with 230VAC between them. In all likelihood the inverter will refuse to use the AC input, but it could also blow things up if you try this.
    You'd have to either reconfigure the inverters into a three-phase system, or get a separate three-phase charger.
  23. Haha
    ___ got a reaction from Louisvdw in Is it a good idea to buy used batteries?   
    Oh man do I have a story. Well two...
    When I was about early high-school years, my dad sent me to go fetch the Bobbejaan (for those who don't know, this Afrikaans also means Baboon). My younger sister (probably around 6 at that time) who was inside the house heard this, and came out of the house, waiting anxiously for my return from the storage place, which was around 100 meters away. She was quite upset when I didn't return with the expected Baboon by my side, but instead with a monkey wrench.
    The second was a case that almost turned into labour unrest. My dad and his employees were putting up a water tank. The tank was tied down with a rope, to prevent the wind from doing any bad things. One of the workers untied the rope at one point, and my dad shouted at him (as one does), don't untie that rope you stupid! Well, no, in Afrikaans we call a stupid person a Bobbejaan, so that is what he said, and as many saffers know... that can also be construed as a racial slur. The worker replied "Ek is nie Bojaan nie!", and then proceeded to sulk for the rest of the afternoon. Count your words as they say!
  24. Like
    ___ reacted to PeterP in Cost of solar generation   
    Current SA EV prices are ludicrous - we got ours 2nd hand for R193K with 35K on clock - so then it's ok. Future EV pricing will be in line with ICE in a few years. We had to replace the other car anyway, so for us it made sense.
  25. Like
    ___ got a reaction from Chris Hobson in Housing Victron shunt? And where to put in circuit   
    I'll tell you why you'd normally want it as close to the battery as possible, and then I will tell you why in your case it probably doesn't matter.
    In many systems the BMV serves as a voltage measurement service. It is closest to the battery, so it has the best idea of the voltage. Other devices might be measuring higher or lower because of voltage drops on the cable. Now the BMV has this red fused cable going directly to the positive of the battery, and there is going to be almost no voltage drop on that cable, so on the positive side you are covered. On the negative side, however, it reads the voltage at the shunt, so you should put the shunt as close as possible to the battery. In most cases that is.
    However... putting it slightly further down does not affect its capability to do its job (managing the SOC), and you already have another even better source of the voltage (the BMS itself, if you can read it that is). For this reason it is not going to matter if you put it on the other end of the cable.
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