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  1. jameshowison

    Why does Victron call for such large wire sizes

    For a 48v system or a 24 or 12v system?
  2. jameshowison

    Why does Victron call for such large wire sizes

    In the manual for the 48v 3000W Victron Multiplus it specifies 2AWG wire from the batteries/busbar to the inverter. I'm trying to understand why. https://backwoodssolar.com/product_attachments/Datasheet-MultiPlus-II-48V-3kVA-35-50-120V-EN.pdf Regular draw is 3000W ie about 62 amps (at 48v, so...
  3. jameshowison

    Complete rebuild of a house - how would you power and heat/cool ?

    I'm late to this thread but you might find http://coolcalc.com a useful place to start to figure out HVAC loads. It's a full on Manual J approach and free for homeowners (they charge to download the official forms for code officials, like $15 or so, it's a cool business model)...
  4. jameshowison

    Ok to attach more than one cable per stud in Lynx busbar?

    Ah, I finally found a picture with more than two wires, looks like they just offset the ring terminal connects by 20-30°. https://community.victronenergy.com/storage/attachments/26381-img-4581.jpeg
  5. jameshowison

    Ok to attach more than one cable per stud in Lynx busbar?

    Ah, because Lynx has cables coming from same direction, so to stack them you flip one. Makes sense! I can see that would limit things to two per stud but that is enough, I think. Some diagrams have the ground from the MPPT stacked in the inverter grounding spot as well, so that could free up...
  6. jameshowison

    Ok to attach more than one cable per stud in Lynx busbar?

    I'm confused about whether it's ok to attach more than one wire to each stud in the Lynx busbar? There seem to be "wire separator" pieces of plastic (which the manual talks about removing). Seems the general position on this is "try not to have too many on a single stud, definitely not more...
  7. jameshowison

    Why fuse SCC wire at "far" end?

    Thanks all, makes sense to me. So it's all about identifying the largest potential sources of current and protecting against those. Almost always the battery is the largest source. But I guess with a really massive solar array they are fused in the combiner box or otherwise en route to the SCC.
  8. jameshowison

    Why fuse SCC wire at "far" end?

    In all the diagrams I see the fuse to protect the wire connecting a busbar and the solar charge controller (SCC, MPPT etc) is at the busbar end of the wire, not near the SCC. Given that the power flows from the SCC to the busbar, it seems odd to me that the fuse is at the "far" end. I'm not...
  9. jameshowison

    Question about battery fusing in Midnite wiring diagrams

    Good point. And the charge controller wire is protected through the circuit breaker 16. But they do say in the notes that this is where DC loads would connect, they just aren't shown in this diagram. See the note for 21: "Battery Positive Bus Bar. This is where we would wire the Battery...
  10. jameshowison

    Question about battery fusing in Midnite wiring diagrams

    Battery positive (red) line runs to bottom of breaker, 15. But also off the bottom of the breaker a smaller red line runs horizontally to the bus bar (21). My read is that the busbar is not protected by the breaker. On the other side of the breaker the thick red runs to 31, the inverter, so...
  11. jameshowison

    Question about battery fusing in Midnite wiring diagrams

    Yeah, those breakers are substantial. But trace the red wires one more time, unless my eyes entirely fail me, the busbar is linked directly to the battery, it doesn't pass through that breaker.
  12. jameshowison

    Question about battery fusing in Midnite wiring diagrams

    I've been looking at the Midnite solar wiring diagrams, such as this one: https://www.midnitesolar.com/pdfs/classic_simple_flow_diagram.pdf The confusing thing is that they don't seem to include the equivalent of a Class T fuse on the battery positive. I see that in almost every other wiring...
  13. jameshowison

    Battery disconnect for nominal 48v systems?

    Thanks all. Some good options there. FWIW, I wrote to Blue Sea technical support with: And they replied:
  14. jameshowison

    Battery disconnect for nominal 48v systems?

    Setting up a 48v nominal system. Two 48v batteries in parallel, the Jakiper server rack batteries. Each has a circuit breaker disconnect on the battery. Most schematics also feature a main battery disconnect right at the positive busbar, using the red disconnects from Blue Sea. I would just...
  15. jameshowison

    Fitted a Midi fuse in a Victron Lynx Distributor. Is it OK?

    Is it ok to have multiple wires coming to the same stud in a Victron Lynx? Think multiple 12 AWG wires, fused with a holder or in-line fuse outside the Lynx? Is it ok to have those going to the same stud? They would definitely fit in the outside holes! I think that's pretty common for smaller...
  16. jameshowison

    Fitted a Midi fuse in a Victron Lynx Distributor. Is it OK?

    Thanks. Reason might well be that I don’t know what I doing :) So you are suggesting a small high amp bus bar pair for the high amp stuff (battery, inverter, link to smaller bus bar). And a lower amp bus bar/distribution center for smaller stuff. Basically add a 48v distribution similar to the...
  17. jameshowison

    Fitted a Midi fuse in a Victron Lynx Distributor. Is it OK?

    So that's a definite no. Not really surprising, given the long stud for the MBRF fuses. So if those are added to the positive bus bar in the Lynx (which is the "upper deck") there's no way the lid closes. This is the "Power In" version of the Lynx FWIW (so no second +ve stud). OTOH you...
  18. jameshowison

    From Growatt to Victron Energy

    Hah, I came to this thread after seeing 48v and Lynx distributor. And you've found the same issue with the fuses for the Lynx distributor. See further discussion, ideas, and links here: https://diysolarforum.com/threads/fitted-a-midi-fuse-in-a-victron-lynx-distributor-is-it-ok.22397/
  19. jameshowison

    Fitted a Midi fuse in a Victron Lynx Distributor. Is it OK?

    Working on a similar issue. I have a 48v battery system and the mega fuses are not sized for reasonable wire sizes for 48v. I asked about this here, but no replies: https://diysolarforum.com/threads/fuse-and-distribution-for-48v-loads-inc-48-12-converter.31390/ There is also a similar...
  20. jameshowison

    Fuse and distribution for 48v loads (inc 48-12 converter)

    I am planning a 48v battery system that includes a few 48v loads. I'm trying to understand the options for fuse to protect the wires to the 48v loads. The loads are: 1. 48v-12v 30amp Orion converter (draws 10amp at 48v) 2. A 48v HVAC system (draws max 30amp at 48v) 3. Possibly a 48v hot water...
  21. jameshowison

    Charging 48v with small arrays/100 VoC MPPT

    Ok, thanks. Hmmm, the Victron calculator is also pointing out the risk of power output dropping as temps rise, such that I can get the calculator to recommend the 100/20 for the CIGS panels only if I keep the max temp below 62°C (which is a bad idea here in Texas and with stick down CIGS...
  22. jameshowison

    Charging 48v with small arrays/100 VoC MPPT

    Rich Solar got back quickly with the temperate coefficients for their 160 CIGS panels: PMAX -0.39%C VOC -0.29%C ISC 0.05%C Using https://www.solarchargecontrollercalculator.com/ and -20°C that gives 105V so too much for Victron 100/20. Thanks, Is that VoC or Vmp? Looking at the Victron spec...
  23. jameshowison

    Charging 48v with small arrays/100 VoC MPPT

    No special reason for the 1.25 other than I had thought I had seen it quoted somewhere, but reading more I see 1.15 times VoC quoted too. Honestly, vast majority of the time we'll be above freezing, but we would like to be able to winter boondock so being functional down to 0°F would be useful...
  24. jameshowison

    Charging 48v with small arrays/100 VoC MPPT

    Thanks, that does give more headroom. And that's calculated with the Vmp not the VoC, right? So for the Rich Solar CIGS 3 panels is only 56.7 so not enough, right? I can look elsewhere but trying to know I'm thinking about this right :)
  25. jameshowison

    Charging 48v with small arrays/100 VoC MPPT

    I have the Jakiper 48v batteries on order: https://jakiperbattery.com/product/jk48v100/ If it wasn't those I'd be getting the Lifepower EG4 48v. I like the server form factor.
  26. jameshowison

    Charging 48v with small arrays/100 VoC MPPT

    I'm planning a 48v system for a travel trailer. I'm trying to figure out the arrangement so that I can purchase the MPPT solar charge controllers. My understanding is that I need to design the voltage on the solar to two numbers. The minimum is sufficient to charge a 48v battery. The maximum...
  27. jameshowison

    How many amps can a victron 100/20 48 volt solar mppt handle? Is this false advertising?

    Might someone give/link to a discussion of “load current” vs “charge current”?
  28. jameshowison

    Shore power for DC Air conditioner (or other constant DC loads)?

    Fantastic video and explanation, thanks!
  29. jameshowison

    Shore power for DC Air conditioner (or other constant DC loads)?

    Thanks. I have seen that long thread, very useful stuff. I think you are discussing the Dometic 12v and the units from undermountac.com (possibly as well as the truck market cabin coolers). I'm planning to use a different dc system, the DC4812VRF from Hotspot Energy. See...
  30. jameshowison

    Shore power for DC Air conditioner (or other constant DC loads)?

    Thanks. Yes, I'll look around for how charging works. I tend to think with a water analogy which is useful sometimes but yesterday I had to search "What happens to solar power when the battery is full" thinking that the incoming water continues so it must cause a flood somewhere :) So that's...
  31. jameshowison

    Shore power for DC Air conditioner (or other constant DC loads)?

    Ah, thanks, that's helpful. In my text drawing I made it seem as though it was a series, but now I'm realizing that these will go to a pos bar and neg bar. btw, is this a standard notation (what's the significance of the arrows, I'm guessing they show flow direction) I'm looking at the...
  32. jameshowison

    Shore power for DC Air conditioner (or other constant DC loads)?

    Right, makes sense. So if the charger has, say, 30 amp capacity and it is delivering 15 amps it'll be much less noisy than if it had 15 amp capacity. (in this case we would be converting 120vac to 48vdc, not 12vdc to 48vdc, but it's the same principle, and maybe you meant 120vac)
  33. jameshowison

    Shore power for DC Air conditioner (or other constant DC loads)?

    I'm looking at an RV build with a DC powered air conditioner (48v Hotspot), but I think the question is relevant for the 12v DC powered air conditioners as well, or any constant draw DC load. Often we will be connected to shore power (think 30amp 120v). For the sake of argument let's discuss a...
  34. jameshowison

    1500w 200ah 12v power box

    Looks great. With this setup can you charge and run the inverter at the same time, or do you always need to disconnect the charger when turning the inverter on?
  35. jameshowison

    48vdc output from solar generator?

    Is there any hope for 48vdc output from the "solar generators" (e.g., Bluetti)? I think they have 48v batteries internally but only provide 120AC and 12vdc output. A weird ask but intended application would be powering the Hotspot 48vdc mini-split heat pump, which takes 48v directly.
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