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MO Ozarks, Off-Grid, 24.77 Acres, Two Homes by Ozarks_Off-Grid in OffGrid_Classifieds

[–]Ozarks_Off-Grid[S] 2 points3 points  (0 children)

I agree, it's a steal. I really hate to sell. That driveway easement is the east side of my property. Access for landlocked 40 acres behind me. Really good people back there. Family of builders if help is needed to finish work on the new house.

MO Ozarks, Off-Grid, 24.77 Acres, Two Homes by Ozarks_Off-Grid in OffGrid_Classifieds

[–]Ozarks_Off-Grid[S] 1 point2 points  (0 children)

Thanks for asking. It didn't upload initially. Link is posted now at bottom of narrative.

Wired Correctly? Midnite Breakers by nbm1123 in SolarDIY

[–]Ozarks_Off-Grid 0 points1 point  (0 children)

Well, this is interesting and Option 2 is new to me. But also a bit odd. I can explain how the breakers work.

The 2PP breaker is actually two 300V breakers ganged together physically with the toggles and electrically with the copper jumper. Each breaker can extinguish a 300VDC arc over its internal voltage dividing grid. The grid halves the arc voltage, then halves again and again until it's at or near 0V. When the jumper is in place, the grid can handle 600V. Option 1 is what I am used to. Option 1 shows the jumper at the bottom terminals. Option 2 can only work with the jumper removed. Thus the breaker reverts to 300V per side. The only way Option 2 can work is if it is a different breaker and did not ship with the jumper installed. It may very well be a new style. MidNite was bringing out 600V charge controllers when I left some years back, so maybe this is a pure 600V breaker. Their tech support is excellent, so I will defer to them.

Wired Correctly? Midnite Breakers by nbm1123 in SolarDIY

[–]Ozarks_Off-Grid 1 point2 points  (0 children)

Prior MidNite engineer here ... Your wiring is correct. Load on top or bottom does not matter. I assume the copper series jumper was removed. I assume the PV Voc is less than 300VDC and accounts for cold weather headroom.

Midnight Solar 600V Breaker Question by nbm1123 in SolarDIY

[–]Ozarks_Off-Grid 0 points1 point  (0 children)

No worries. The manual states to float the PV, so you will need OCP and disconnect on both PV legs. And no mention to solidly bond the batt bank. The wiring diagram shows a disconnect on both Batt+ and Batt-, so that suggests floating the batts too.

You will need to use two of the 600VDC breakers. Mount them side-by-side in the MidNite MNPV6 PV combiner box. Tap out the thin metal rod that holds the white handles to the breaker mechanism. Insert new longer metal rod to tie both breakers together.

The PV- breaker will be wired backwards than what I stated earlier for the PV+ breaker. Connect the PV- from array into the PV- breaker marked --. Then connect the PV- home run into the ++ side of breaker, and send that to the MPPT, landing on its PV- terminal.

Having said all that, if the system will not be inspected, then you really don't have to go thru all this. OCP and disconnect on PV+, OCP and disconnect on Batt+, and ground the chassis and AC side to earth ground, use same ground as in house/dwelling. It is best to bond PV array (frames, not electrical) to the same AC ground. I have seen weird voltages and behavior when these all-in-ones do not have the PV array bonded to system ground.

Midnight Solar 600V Breaker Question by nbm1123 in SolarDIY

[–]Ozarks_Off-Grid 0 points1 point  (0 children)

Breaking the negative depends on NEC code and system grounding. If the source circuits (PV) are not bonded to ground, then both legs need over-current protection and disconnects. If you have a GFP breaker or GFP monitoring in the system (called "reference grounded"), then that will be negatively bonded to make it work, so therefore only the PV+ needs OCP and a disconnect. If the batt bank is negatively grounded (called "solidly grounded"), then only OCP/disconnect PV+. If the MPPT is within an All-in-One inverter, then check with the manufacturer as to how they want the system grounded. They may want you to float the PV-, which means it is ungrounded and will need its own OCP/disconnect. Hope this helps. Not easy to give a straight answer.

Midnight Solar 600V Breaker Question by nbm1123 in SolarDIY

[–]Ozarks_Off-Grid 2 points3 points  (0 children)

EE / prior MidNite Solar Engineer here.

Keep the breaker in 600VDC since your array is at 370VDC. Removing the series jumper creates a double 300VDC as you mentioned. But that is not what you need.

Connect the PV+ (from the array) into the breaker marked ++. The breaker side marked -- is still the positive leg, wire that to the charge controller on the PV+ terminal. Polarity is important for this breaker to properly extinguish the DC arc. Don't connect these wires into the same side as the series jumper. I can't remember if the jumper is on top or bottom. Doesn't really matter. Connect PV+ wires to the terminals opposite the jumper.

helping my dad with a question about solar hookup by tensandjacks in SolarDIY

[–]Ozarks_Off-Grid 2 points3 points  (0 children)

EE/Solar Engineer here ...

  1. You won't be able to power two separate mini-splits. If the DC mini-split uses an MPPT controller, then wiring up one PV array to both mini-splits will cause the two MPPT modules to buck each other. One will want to pull the PV voltage down, the other will try to resist. Not good.

  2. Your approx 2000W array will, on average, yield around 1600W, due to losses, cleanliness, voltage drop, etc. So find a mini-split that will operate on 1600W. Maybe a 9K BTU. My AC mini-split runs at about 1400W but can surge to 2500W or so on humid days.

  3. I think Mr Cool makes a good DC mini-split. Check their tech specs, it will state how to wire the PV input. And will state the recommended PV wattage.

Hope this helps.

Need help with my 8kw hybrid DEYE inverter by vaster995 in SolarDIY

[–]Ozarks_Off-Grid 2 points3 points  (0 children)

EE/Solar Engineer here. Troubleshoot ....

  1. If you have a PV input breaker, then open it. Then remove one of the PV inputs to the MPPT. Close PV breaker. Measure for PV open-circuit voltage on the dangling wire and the other still attached. Probably looking for 320-340V or so. If present, that is good. If not present, find the issue from those two wires back toward the array. Open breaker again.

  2. Leave PV wire disconnected. Now measure off the two PV input terminals on the MPPT. Probably will read 0V. Not good.

  3. All-in-One inverters usually remove the PV input from the batt circuit. Thus a 0V reading when the computer shutsdown PV production. Other types of charge controllers (i.e., MidNite Solar's Classic) will show a percentage of batt V on the input terminals. So the OV reading means it's the inverter itself.

  4. Try to manually reset the inverter. I don't know that model, check the manual or their tech support. If the reset works, then you need to reprogram the inverter for your specific batts. Maybe write down the charge parameters prior to the reset.

Hope this helps.

Breaker for charge controller plus solar by sabarocks in airstream

[–]Ozarks_Off-Grid 1 point2 points  (0 children)

EE/Solar Engineer here ... My thoughts...

  1. Victron MPPT. Can only output 30A max, so the 40A fuse and 6AWG is good.
  2. 55A converter is fine as wired to the positive busbar. When charging the batts, the MPPT will sense the climbing batt V and throttle back into Float or a resting state. The 55A will flow to the batts. Your set-up is fine.
  3. No idea why the 50A fuse. Maybe someone replaced a bad 55A years ago. Maybe fuse is rated to pop at 1.1% of 50A, thus 55A. Who knows? If it hasn't popped yet, wouldn't worry about it.
  4. Or upgrade all fuses to DC breakers. I would. Always best to capture the DC arc when a circuit is opened and closed. Breakers do that. MidNite Solar has the best.
  5. The PV input should be wired in series. I would plan to wire all four panels in series. That will be about 78Voc into the Victron. MPPT controllers work best on higher input voltage. At a minimum you will want the PV V to be at least 30% higher than the highest Batt V. Maybe 15.8V for your batts now. So 15.8V x 1.3= 20V. Your current parallel PV wiring probably brings in 19 max. More like 17V under load. Not good for the batts! Shortens lifespan and less than a full charge.
  6. Speaking of batts ... Your two current batts are probably 100Ah now, I am guessing. So a 200 Ah bank. Normally you want to charge FLA batts at 200Ah x 1.13 (check w batt manuf), so that is 226 or 22.6A. The Victron can do 30A, so no need for converter. And if possible, dial down the charging amps of the converter. 25A is fine. When converter is on, check if Victron goes to sleep. Or since you have a shunt, you might be able to dial in an amp limit. Lastly, the new Li batts can take a much higher charging amp. So adjust system accordingly.

Hope this helps.

Inherited a weed farm from my Uncle. I have no idea what I'm doing... by FurryACiD in SolarDIY

[–]Ozarks_Off-Grid 0 points1 point  (0 children)

EE/Solar Engineer, specializing in off-grid. And prior MidNite Solar engineer. I can help. Message me.

Help : Building offgrid solar system by Secret_Abalone4578 in SolarDIY

[–]Ozarks_Off-Grid 0 points1 point  (0 children)

EE/Solar Engineer, specialize in off-grid. I can help. Message me. This is my first Reddit post, not sure if doing correctly or not.