very interesting. thanks for the info. keep us updated
New 10kw NHX AIO From Watts247
- Thread starter Kornbread
- Start date
I like to repurpose things. The two 6panel pole mounts in the background were made from visiting the local scrap yard. The poles are ~6" ~1/4" thick aluminum from what looked to be some kind of very large dismantled electrical distribution system. The swivel mounts were made from a scrap piece of I-beam.
The main backbone is 3"x4" rectangular tubing ... from the scrapyard, and 2"x2" horizontal stringers. The 3"x4" backbone pivots on a 1" bolt allowing the panels to tilt. The short piece of channel strut allows the tilt to be locked in place. The 1" pivot area of the 3"4" backbone is slightly off center, from long end to long end, to allow for easy tilt adjustment. To change tilt, grab the channel strut with one hand, remove nut, alter tilt, tighten nut, easy peasy. They're two rows of 3/8" bolts down the lower portion of the head. Loosen those bolts, turn, retighten bolts.
This is the new swivel head for next 12panel pole mount. It goes where the bucket now resides. 3/8" flat stock. You'll never guess what the pole is made from ... you know those yellow poles in the parking lot that keep stuff from getting ran over? Yep. Welded two of those together.
Ingenious stuff. You might want to post it on this ground mount megathread if you haven't already.
TylerW
New Member
Thx so much for you updates...please keep them coming...I have a question please...is it possible to track monthly grid use and start on say the 12th of every month? Is it possible to export/sell back a specific amount each month? I need to use about 100KW/month from the grid and would like my "batteryless" grid tie to take care of the rest...
CuriousJohn
New Member
I don't know of any inverter that has that level of control built into it. Maybe someone else can speak up. I don't see that in the NHX for sure. I think you could probably do those things with solar assistant and/or home assistant.
The NHX can limit to cover your internal loads only if you want it to. Or it can cover internal loads AND export excess to the grid. It can limit its overall output to a percentage of capacity. For instance, 50% setting would mean it would never supply more than 5000 combined watts to your home and/or grid. It does track usage stats, so it does know how much it has exported - or at least the Solar Man gives you that info. But there are no controls in place to limit production once you have hit your limit. As I mentioned though, I would bet you could do that with some automation tools as I mentioned.
TylerW
New Member
Thx much appreciated...also I saw in a video that "Anti Islanding" was selected, which of course we want and I think is mandatory. My question is, if the grid goes down, can you de-select that anti islanding so that you could just turn the main breaker off and use your existing "grid-tie" connection to feed the main panel when grid goes down? There might be a UL regulation against that, but it would be an easy way to feed your panel when grid goes down...the risk is if you forget to turn anti islanding back on when grid is back and you restore back to normal....and also do the CT's keep track and tell you how much power you've used from grid? Just to keep the power company honest...
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CuriousJohn
New Member
That would be a very bad idea. If you did turn off anti-islanding, you would be attempting to power the whole grid. And of course you are putting line-men at risk.
The right way is to have a critical loads panel. You would NEVER disable anti-islanding, and you would instead power everything on the inverter outputs.
I can only think of odd use cases where you would want to disable anti-islanding, and it would pretty much never be when you are connected to the grid.
Yes the CT's track power in and out.
If he shuts off the mains disconnect at the meter, it cannot feed anything back to grid. If he forgets to turn anti-islanding back on after connecting back to grid, it could be big trouble, dangerous, and have possible legal liability when/if the grid goes down again, although, I postulate the inverter would shut down almost immadiately as it wouild be trying to drive a short. Still, those few seconds could cause harm to something, or someone.
TylerW
New Member
I did mention the main breaker would be turned off, so no chance of feeding the grid...also the CT's would be set for zero backfeed...but there's still a risk there that the breaker could be turned on without enabling anti-islanding I suppose...I don't want a second panel, cuz I'd pretty much have to move everything over to it, and my house in Mexico has regular power outages...so ya the clocks in the house are always flashing...the engineer in me wants to create a safe way to do this, so I'm looking for ideas and insight...
TylerW
New Member
I'd love the 18K but I get get 2.5 of the NHX for the same price...and grid-tie is all I really need...18K is a very expensive grid-tie option...but I hear the 6000XP may get grid interaction soon??? it's available outside USA as a hybrid...
@CuriousJohn could you check the pv inputs for ac. I'm curious if this inverter has ac riding on the pv inputs.
Which brings us to grounding. I assume it would be better to run a ground back to the central grounding point but, IIRC, NEC allows or recommends grounding at the pv panels. Why the NEC recommendation and which is better?
Which brings us to grounding. I assume it would be better to run a ground back to the central grounding point but, IIRC, NEC allows or recommends grounding at the pv panels. Why the NEC recommendation and which is better?
Zwy
Emperor Of Solar
No, NEC requirement is to run EGC to the AC system grounding. This is the only requirement under NEC for array grounding.
Ground electrode at the array is allowed but not required, it is called an auxiliary ground. Any nearby lightning strike by an array with an auxiliary ground electrode can have a gradient pulse that enters the electrical system.
No what?
If the solar panels are mounted on metal ground mounts, are they not already grounded? In a nearby strike, wouldn't this also create the same difference in potential as grounding the array separately from the central ground electrode? In that scenario, is there any reason to also run ground to the central electrode?
If the solar panels are mounted on metal ground mounts, are they not already grounded? In a nearby strike, wouldn't this also create the same difference in potential as grounding the array separately from the central ground electrode? In that scenario, is there any reason to also run ground to the central electrode?
Zwy
Emperor Of Solar
No, the panels are not grounded, the panels are merely tied to earth. There is a difference. Grounded would be where the all metal in a system is bonded to the N-G bond to clear a ground fault using a low impedance path. An array with a metal ground mount with poles in the ground is not bonded with a low impedance path to the N-G bond.
Yes, it could create a scenario with a gradient pulse entering the pole in the ground and possibly entering the solar system. SPD's are installed to minimize this potential. Nothing is a sure thing with high voltage discharge from lightning, the idea is to minimize possible risk.
The purpose of an EGC from the array to the system grounding electrode is not for lightning protection, it is to protect electrical shock from occurring if the array was energized with AC power. The EGC provides a low impedance path back to N-G bond to clear the ground fault. In the case of non isolated charge controllers, it also will dissipate any trace AC voltage on the array.
Don't confuse lightning and grounding. The 2 are distinctly different. NEC requirements are any metal that can be energized by AC power needs to be bonded to the system ground.
CuriousJohn
New Member
Sure, I can see if I can detect any AC on the PV inputs. Is there a reason you think this is happening?
Maybe I should have said run a ground back to the central ground/bond point. Doesn't running a ground (back to the central ground/bond) from each array, which are mounted on steel mounts, so, tied to earth, create even more possibilities for catastrophic damage from a difference in potential? Should ac ever be riding on the solar panels? Trying to weight all the pros n cons in this situation.
Zwy
Emperor Of Solar
Non isolated AIO's with a charge controller will usually have AC on the array.
Here is Adam getting some sparks.
Mahendra Gomanie
Solar Enthusiast
Yea saw this on the mpps
I am very close to buying this inverter, the N3H-10K-US. Seems ot have the features I need, seems to work well enough, the price is definitely right, etc.
But I have these concerns:
1. What batteries can it talk to? It seems to be limited in the protocols it can handle and I haven't seen anyone successfully hook this to a bank of rack batteries and have it report their state properly. I would really want it to talk to the batteries properly.
2. How well does it handle UPS duties? That is, switch from grid to battery when the grid drops fast enough to not cause reset of your electronics devices. I'd love to see a video of it handling this case. Ian sent me a video of it not dropping an EV charger, but that's not quite the same as computers and clocks. The published spec is 13 ms which is a little worse than many others around 10 ms.
3. Will it be reliable? This is going into an installation at my mother's house which is in Florida and I'm in Indiana. If it has issues, that will be problematic. I will certainly provide a bypass option for her, but the ideal is that it gets setup and "just works" without a lot of attention.
What do you think, will this work for me?
Mike C.
But I have these concerns:
1. What batteries can it talk to? It seems to be limited in the protocols it can handle and I haven't seen anyone successfully hook this to a bank of rack batteries and have it report their state properly. I would really want it to talk to the batteries properly.
2. How well does it handle UPS duties? That is, switch from grid to battery when the grid drops fast enough to not cause reset of your electronics devices. I'd love to see a video of it handling this case. Ian sent me a video of it not dropping an EV charger, but that's not quite the same as computers and clocks. The published spec is 13 ms which is a little worse than many others around 10 ms.
3. Will it be reliable? This is going into an installation at my mother's house which is in Florida and I'm in Indiana. If it has issues, that will be problematic. I will certainly provide a bypass option for her, but the ideal is that it gets setup and "just works" without a lot of attention.
What do you think, will this work for me?
Mike C.
