Well said, Smart$ and J ben. Thanks.
Type: Posts; User: Zee
Well said, Smart$ and J ben. Thanks.
I faced a corrugated metal roof only once. Typical, true wavy, every couple inches.
We pulled the existing gasketed screws where needed and in its place set the "top slider" of a pro solar tile...
I imagine that vertical, dc, double 3" conduit could be furtehr reduced if you combined on roof.
So....2x32 conductors= 64 wires/4 inverters = 16 per inverter = 8 strings each?
WHy aren't you...
If inverter vents top and bottom, and if you have no/minimal side clearance on inverters.......and you transition to THHN on your DC Spaghetti wires above this room, thus significantly...
Definitely transition to thhn from pv wire, once you leave PV array.
3" EMT is insane. the fill factor on pv wire is triple that of thhn. same gauge. At least.
some AHJ's don't allow load side, period. Check.:eek:
"....you could make the argument that the [subpanel feeder] conductor can fall under the 120% rule. "
I agree with quad suggestion, and everything else, but I won't waste space writing...
Ideally, you want to attach at the peak of the "ridges" . All water flows down from there. Water flows in the valleys.
The roof itself attaches in this manner, at ridges. See rubber washered screws....
Not wanting a hole in wall and wanting an inverter on said wall is incompatible.
You gotta drill a hole for a screw.
Use a blue TAPCON screw for stucco/concrete that effectively fills hole in any...
I agree with other comments on downsizing most likely being fine.
2p175A would be the very next step down, I have done it many times, and a 175A main breaker should suffice to feed the house...
A couple more options that are available:
Replace the main panel (not upgrade the service to 400A) with another 200A panel. This panel should have one of the following:
a. add'l SUPPLY SIDE busbar...
Yes, I agree:
If two separate busbars are fed by a 4 pole breaker (which in essence is a pair of separate 2pole breakers with handles tied)....then it really is a split service, AKA a main with two...
Unless 2014 Rapid Shutdown requirements apply:
If dc conduit is metal inside building, then dc disco adjacent or integrated with inverter is per code.
AC disco within line of sight of...
I have heard of termination issues for the finer stranded wires, not the 7 strand.
(namely fine-stranded 2/0 and 4/0 cables for battery based PV)
"NABCEP certification, the one that is hard to get." :p
If someone is giving you wrong answers.......No wonder!:jawdrop::happyno:
I am a big fan of NABCEP by the way, it really is a meaningful...
Can you switch inverters around so that you get down to 200A?
I would think so, from 208.4 Amps.... you're getting mighty close.
Usually you would find that you have extra capacity left over on...
Yes, my unstated point too: plenty of labels warn of high voltages already, ungr. circuits, line and load energized etc, . And on larger systems labelling well becomes worthwhile.
I stick a label on the outside to appease AHJ...
.....and one on the inside to appease my conscience and avoid all destructive UV.
Sharpie will fade and burn out. So will my labels (when don't...
Only experience was years ago...when solar was new...we just tapped into busbars with any lugs that fit.....but it won't past muster now.
My experience is when i call a manufacturer of equipment...
Yup. Says outdoor.
How do you label V and Amps?
All this means is you have to run two dc circuits as OP mentioned, instead of one. Say...12 and 18 KW each.
Everything points in that direction..... there is a Connection Unit, as SMA calls it, a CB...
From SMA Data Sheet:
"Max. Input current / per MPP tracker ........66A/33A"
That indicates max 33 Adc per input. And 66 Adc only if you use both inputs.
What they said.
Consider wire, sure. However, also consider conduit size in terms of extra work and cost. It' s been a while since I used larger than 1/2" EMT!:roll:
Before, I used to...
on DC systems use
Imp for Voltage Drop calcs!
(not Max Sys. V, Voc or Isc)
If Blake writes it, it is well though out.:D
And remember: every time you up the Volts, you ALSO drop the Amps! Double benefit for V drop.
On a recent ground mount I had...