Most reacted posts

  • Post in thread: Ac Volts bleeding into solar lines?

    SS first line support is unqualified. timselectric has a lot more knowledge than SS first line support and 99% of the turnkey installers that might turn up to your house.
  • Post in thread: How to meter what the panels are producing.

    How would the shunt determine the solar that is unused because it cannot be used by loads nor absorbed by the battery?
  • Post in thread: HELP HELP BLUETTI

    Post spec sheet screenshots... They're going to be on the Santan website or wherever you are thinking of. Because there are an infinite number of possible used panels and we can't get anywhere efficiently until you paste that info in As well, to be polite and help with efficient answers paste...
  • Post in thread: Failed Inspection - need some advice and guidance for NEC 690 infractions.

    It needs to be an approved UL9540 pair of inverter and battery combination. The battery positioning and protection within the structure is also prescribed in NEC or international residential code as adopted by your state (I think the latter). So that might be another rude awakening if inspector...
  • Post in thread: Ac Volts bleeding into solar lines?

    Which post talks about this? The AC on the frame is induced. There should not be any DC on the frame.
  • Post in thread: Signature Solar's EG4 8k Will it pass inspection in California and Hawaii?

    I haven’t bought any EG4 but when I was considering it I got a very bad taste in my mouth with the company’s professionalism/level of caring with CEC and other California requirements. I don’t think anything EG4 has ever ended up on the list. Let’s compare this to Chinese manufacturers selling...
  • Post in thread: Why is string voltage drop over 3% bad?

    Physics wise the same waste heat / power loss should be generated per unit length of conductor, modulo the positive thermal coefficient of resistance. However heat is not temperature. Temperature is related to how the heat is dissipated/not dissipated, and this definitely will not be symmetric...
  • Post in thread: How do you prevent back feeding the grid during outage?

    Basically something that synchronizes phase and frequency with an incoming signal. A grid tie inverter needs to generate output at the same frequency as grid, but with a controlled phase and voltage difference to push different amounts of apparent power back into the grid.
  • Post in thread: Zero Eport and the EG4 18Kpv

    Zero export parallel operation without interconnection agreement is an edge case in the grand scheme of things (ie not the echo chamber of this DIY forum) and quite possibly not the most profitable/easy to serve customer profile. Also zero export is very hard to implement in a way that escapes...
  • Post in thread: Failed Inspection - need some advice and guidance for NEC 690 infractions.

    Plenty of posts about this on the forum if you go looking... Personally I always like the installations with wireways + EMT into inverters and disconnects, over what you see in videos. This is a pretty reconfigurable, albeit expensive and timeconsuming to build in the first place, installation...
  • Post in thread: UL 1741 MUST see for all

    Code explicitly says listed, and not UL. Which by definition means any NRTL. So this is reiterating what well-trained inspectors and contractors are supposed to know…
  • Post in thread: Failed Inspection - need some advice and guidance for NEC 690 infractions.

    Yes this is something that can't be repeated enough. In the majority of cases PV has no overcurrent protection. Or even the capability of rock solid ground fault protection because there's no code requirement / available equipment for this type of MLPE protection at the panels. EG 1P or 2P, no...
  • Post in thread: Why is grounding so HArrrd!!!

    It would be great if there could be a hacktivist that goes around deleting all the bad info from the Internet… Anyway the meta solution for OP is to get better at critical picking of sources (websites and posts)… I would guess that 50% of the answers on Google are wrong
  • Post in thread: Running PV wires in an attic/indoors/basement guidelines?

    DC circuit needs to be in conduit or cable after exiting array. DC circuits also need to be in metal conduit within the building. Solar is allowed to use FMC or MC within building with extra protection or big enough conduit size to be strong enough to not need it. Need to comply with the solar...
  • Post in thread: EMT as solar panel rack ?

    Yup UL listed (or more specifically listed by some NRTL for compliance) is always relative to one or more specific standards. Another problem with EMT is that it will be a huge labor PITA. All racking systems have evolved labor saving components that are engineered to work properly...
  • Post in thread: Solar Assistant (Possibly) Voids Warranty on EG4 Inverters?

    Pretty sure crowz posted that hint because that implies the inverter is capable of taking power from both host USB and its internal power supply for some components. That is a liability and can lead to damage. There's also zero functionality benefit to it other than saving some micro bucks on...

    Best case if you YOLO into plugging grid tied inverter into off-grid inverter is that it only shuts down before anything bad happens. Manufacturers of AC coupled equipment warn about damage too in some edge cases if the equipment is not sized correctly (though they do not enumerate these). IIRC...
  • Post in thread: Need Advice: Expanding My Solar System Due to EV Commute

    It was but the installer association guy who was constantly updating the subreddit knows WAY more about gaming the NEM2/3 than the best person on this forum. And probably has helpers feeding him info.
  • Post in thread: Ac Volts bleeding into solar lines?

    At least from the stories of support woe, a lot of them are also really bad at knowing what they don’t know or admitting to it
  • Post in thread: DC Fast Charging using FREEWIRE Chargers?

    Ok to simplify this problem with an alternative option as a thought experiment. Why not consider using 48V battery to 240v inverter and then use onboard charger? Very mature set of components. Don’t need to cobble together HVDC battery pack and DC charger (there have been posts on r/evcharging...
  • Post in thread: Connecting from a RV pedestal to an inverter 200' away

    Might even consider adding a second subpanel right at the service that can be completely de-energized without calling POCO. You should be able to find 100A-125A branch breakers for most brands
  • Post in thread: PWM controllers: Do they cause high voltage disconnect of inverters? Other voltage problems?

    You are forgetting that the solar panel and battery will reach an equilibrium voltage. And it cannot be that much higher than the battery voltage, otherwise there would be way too much current going into the battery. So it’s more like swing between (battery voltage + V, battery voltage), where...
  • Post in thread: Solar to electric vehicle-direct

    Level 3 is DC charging. Also not discussed here but worth mentioning. DC charger requires the shore side equipment to handle all the responsibility of charger, including communications with EV, DC DC converter to provide CC and CV behavior at appropriate points in the cycle. DC EVSE also needs...
  • Post in thread: Question regarding PV Panel on the roof overhang

    I've heard that this is doable, but I'm not super familiar with the code. FWIW I did a layout on an aerial photo / old CAD from previous install. Then contracted a designer to convert that my hand-drawn layout into submission-ready plans. That would help address this kind of question. It also...
  • Post in thread: NEM PGE Application Questions

    Update: I just got the pre-engineering kudos from PG&E, it looks like this: CRM state: E-mail
  • Post in thread: Why is string voltage drop over 3% bad?

    The voltage drop may be enough to hit a boundary condition where the MPPT cannot operate. I think if the string is riding the edge of a voltage limit voltage drop might be more important. Could have happened at 3% too.
  • Post in thread: Hoymiles HMS-2000-4T-NA [240]

    The modbus registers are fairly well documented by Hoymiles. You can also use the DTU to send commands down, like curtailing the output, which I think will be useful if I try AC coupling to HM microinverters.
  • Post in thread: Anyone doing net metering using Victron Inverter?

    This has been my assumption and I would love to be corrected, but I kind of crossed off Victron from my list of ESS candidates when I saw that MultiPlus only got 1741 certification. IIRC I looked at the actual certificate to see that it is 1741 only. From the fact that the certificate was...
  • Post in thread: UL9540A for server rack form factor -- how would it work? What info have you found overall?

    Simple, UL9540A is not the same as UL9540. It’s a terrible naming convention. UL9540 is what you need for installation in places that require a listed ESS
  • Post in thread: Connecting from a RV pedestal to an inverter 200' away

    I think OP punched in the wrong numbers. I got #4 as well for 240v@50A. Maybe the distance was doubled or 120v was used or some bad calculator was used. Also is 3% limit really necessary? The grid voltage can vary more than that anyway. Polaris makes 250mcm -6 etc that covers the range here...