Need advice on drawings

[foo1bar]

I've just been through this process myself, though in a much easier jurisdiction. My view is what you have looks pretty good. I don't normally disagree with Sensij who bats close to 1.000, but the M250 has a maximum output of 1A and you have 18 of them so I think you are fine with a 20A breaker.

Nope - need to multiply 18A by 1.25 because of NEC requirements - I think it's because it's a "continuous" current - would have to look it up.

Here's an article with NEC code references:

http://www.smainverted.com/2015/02/17/properly-sizing-a-pv-inverter-breaker/

[tehan]

I've just been through this process myself, though in a much easier jurisdiction. My view is what you have looks pretty good. I don't normally disagree with Sensij who bats close to 1.000, but the M250 has a maximum output of 1A and you have 18 of them so I think you are fine with a 20A breaker. You are missing a few things that I believe will generally be required: (1) datasheets for your panels, inverters, and rails and (2) calculations of wire ampacity and structural loading (The Ironridge webstie has a great tool that will provide you with all the calculations you need). Good luck!

[samotlietuvis]

Vow, that’s unbelievable experience for you.

Went for the 2nd time to the permit office, I they “failed” me for missing solar panel installation copy that was actually there. I showed it to the guy. He looked at it and told me to come back tomorrow.

Don’t forget to tell your permit guy what a great service he does to your city.

Today was a WOW day.
I talked again to the inspector and what a totally different person he was. day and night!

He spent more time explaining to me the whole process on how the drawing should look like, he actually made copies for me to follow!!!
Then he called the building inspector to explain to me what is needed from me to show them, like wind and snow loads. most of that info
is found at ironridge website.

I shook their hand and thanked them for the help that they provided me with.

Amazing experience.

Now back to the drawing table.

P.S. steve, your drawings are coming handy indeed

[J.P.M.]

Hi J.P.M., thatns for your comment.
I actually did contacted the town and they have no clue to what is required from a homeowner diy solar installation, they always had contractors doing
the work for the homeowners. as i said before, i do my own repair, upgrade in my home, water heater, gas line, boiler, driveway, fence, generator and so on.
and i always apply for permits and have my work inspected by the AHJ inspector. My famil's safety is my first priority.

I do have more building drawing but in different pc, and i dont have access to them right now. but i did all the calculation for wind, snow load, rafters spacing and more diagrams on setbacks from gutters etc.

I just want to make sure that is the inspector denies my application is because of valid point but not that i didnt hire a PE for their seals and stamps.

sensij, thanks for your input.

For my part, you are most welcome. Seems like you got religion.

[GreenTeeCrazy]

Today was a WOW day.
I talked again to the inspector and what a totally different person he was. day and night!

He spent more time explaining to me the whole process on how the drawing should look like, he actually made copies for me to follow!!!
Then he called the building inspector to explain to me what is needed from me to show them, like wind and snow loads. most of that info
is found at ironridge website.

I shook their hand and thanked them for the help that they provided me with.

Amazing experience.

Now back to the drawing table.

P.S. steve, your drawings are coming handy indeed

[sensij]

@foo1bar,

Correct, the the wires from string 1 and 2 get combined in midnite w/2 20 A breakers, then connect to MainPanel w/20 A double pole backfeed breaker

Foolish comments like this are probably why the inspector you talked to is not interested in looking at plans produced by someone not qualified to make them. I'm not sure which fundamental you are missing, but somehow you are not grasping one of the following:

1) Microinverters produce 240 V power
2) 240 V power in the US has two hot legs, 180 deg phase difference
3) All hot legs must have over current protection.
4) A double pole breaker can be used to protect a circuit with two hot legs, in this case, a single 240 circuit.
5) A 20 A double-pole breaker is rated for use on circuits which carry up to 16 A (80% of 20A = 16A)
6) The full current flows through both legs at any moment in time.
7) When you combine two parallel circuits, the currents add together.
8) Each string requires its own two pole breaker when you combine them. If you were planning on using only two single pole breakers in your combiner, that would also be wrong. There would be 4 hot legs, but only two would be protected.
9) The breaker going into your main service panel needs to rated for the combined current. In this case, you need at least a 25 A two pole breaker, and your conductors need to be large enough to be protected by that.

[GreenTeeCrazy]

@foo1bar,

Correct, the the wires from string 1 and 2 get combined in midnite w/2 20 A breakers, then connect to MainPanel w/20 A double pole backfeed breaker

@sdold;
PM sent, anything can help Thank you

I totally agree, My drawing were not explained properly

[sdold]

Hi GreenTeeCrazy: I did drawings for two Enphase M215 systems in CA that passed two different AHJs without much trouble, they are in Autocad and PDF form, if you'd like to use them for ideas give me your email address and I'll send them to you.

I think the building dept.'s willingness to work with you depends a lot on how hard they have to work to figure out the drawings, and how much of what they need is missing, so I think you're on the right track.

[foo1bar]

Enphase M250 has a limit of 16 micro inverters per string. 16*1.25=20
I have 2 strings of 9 inverters. 9*1.25=11.25 but my system will come shipped with 20 A breaker.

You have in your plans that you combine those 2 strings before it reaches the main panel - what breaker size is appropriate for that?
What wire size? Did you calculate with temperature derating if that wire is in conduit on the roof? (How far off the roof is your conduit?)

I think some AHJ are more toward helping contractors than homeowners

My experience is usually they like homeowners better and will be more helpful to them.

[GreenTeeCrazy]

1) Plans may need to show grounding details
a) frame
b) electrical safety

2) Enphase inverters. Why ? Do you have shade issues from trees south of you ? Otherwise, I'd suggest 1 or 2 String inverters. Yes, you get DC wires with that, but you don't have to pull 3 panels to replace 1 bad inverter next year.

I did miss grounding from my drawing, but now that you mention it... i'll be adding it to the One-Line electrical drawing

I am not quite sure what you meant by electrical safety?

Enphase inverters were my preference of choice for their easy configuration and the ability to access and check the performance of each one from a web browser.

I think it'd make things much clearer.


I would include:
* Rafters are 16" OC
* Rails will have minimum of 4 attachment points per rail, 48" between feet and no more than 24" cantilever.
(Or whatever Ironridge's design assistant says is OK for span/cantilever. )


I *think* you are saying that on your plans between roof1 and roof2 is a valley (running roughly North-South) - but that wouldn't make sense for your drawings showing the rain gutters.
I'd definitely recommend either an aerial shot of your house (from google maps/earth or from 2nd story window across the street) or an isographic drawing.
Even a street level picture with panels photoshopped in would help establish what you're doing.

BTW - I didn't see on the plans an indication of where your combiner will be physically placed.

Good luck

Again you came through with more pin-point diagnostics. I' need to improve my drawing so anyone can have an idea of what they are looking at.
I'll also be contacting my vendor for their assistance.

Some AHJ requires wet stamp plans by the structural engineer and also signature of the C10 license holder or wet stamp from the electrical engineer.
18 Enphase M 250 , each one at 1A @ 240 V, 18x1 A x 1.25 =22.5 A next available breaker 2 pole 25 A . Good luck with you project.

Enphase M250 has a limit of 16 micro inverters per string. 16*1.25=20
I have 2 strings of 9 inverters. 9*1.25=11.25 but my system will come shipped with 20 A breaker.

I think some AHJ are more toward helping contractors than homeowners

But i just need to keep a positive attitude and start from scratch again.

[Mike90250]

1) Plans may need to show grounding details
a) frame
b) electrical safety

2) Enphase inverters. Why ? Do you have shade issues from trees south of you ? Otherwise, I'd suggest 1 or 2 String inverters. Yes, you get DC wires with that, but you don't have to pull 3 panels to replace 1 bad inverter next year.

[foo1bar]

VERY informative post, exactly what i was looking for, much appreciated.
- I'll redo my drawing with more colors if it will make the town inspector happy.

I think it'd make things much clearer.

- To do: quick mount point installation with spacing between them, 4 quick mount connection per rail.

I would include:
* Rafters are 16" OC
* Rails will have minimum of 4 attachment points per rail, 48" between feet and no more than 24" cantilever.
(Or whatever Ironridge's design assistant says is OK for span/cantilever. )

My house is split level, so the ridge is horizontal next to the chimney, (Will be corrected with color) the valley is between the 2 roofs.

I *think* you are saying that on your plans between roof1 and roof2 is a valley (running roughly North-South) - but that wouldn't make sense for your drawings showing the rain gutters.
I'd definitely recommend either an aerial shot of your house (from google maps/earth or from 2nd story window across the street) or an isographic drawing.
Even a street level picture with panels photoshopped in would help establish what you're doing.

BTW - I didn't see on the plans an indication of where your combiner will be physically placed.

Good luck

[solarfrank]

Some AHJ requires wet stamp plans by the structural engineer and also signature of the C10 license holder or wet stamp from the electrical engineer.
18 Enphase M 250 , each one at 1A @ 240 V, 18x1 A x 1.25 =22.5 A next available breaker 2 pole 25 A . Good luck with you project.

[GreenTeeCrazy]

1> IMO the plans aren't very readable. I can't tell which lines are dimensions and what are denoting structures/materials.
2> Is there a requirement of 3' on each side of the ridge for fire setback? Throughout CA there is, and I think other places too.
3> The last attachment I am interpretting that as the "rafters" are every 16" OC running horizontal? That'd be really odd.
A> Are you sure it's 16" and not 24" OC? Many roofs are 24" OC - so if you haven't checked, check.
B> Almost always rafters are running with the slope of the roof, not across the slope.
C> I don't see how many attachment points/feet there are - or what is being used (ex. which quickmount product)) I didn't see a "Attachment points every 48 inches" or something similar. (Or are you doing attachment point on every single rafter?)
D> I assume there are multiple microinverters that aren't shown? IMO you need to show them. Do one page per roof face if necessary. Use color or grey fill to make it easy to differentiate between different things.
4> Make explicit the roof pitch - and/or include a photo or non-top-down drawing to show things. (I assume the ridge is between roof 1 and roof 2 - with downslope being to left on roof1 and to right on roof2) An isographic drawing could make that clear.
5> Do you have any vents/chimneys that you need to deal with (dryer vent, plumbing vent, cooking hood vent, bathroom fan vent, HW heater vent/chimney, furnace vent/chimney, etc.) If you're going to have to move them or work around them, put that in your plans.

I think this is a good example plan:

http://santaclaraca.gov/Modules/ShowDocument.aspx?documentid=1666

Obviously it'd be better to use as a starting point an example plan from your AHJ if they have one.
But if they don't have an example, I expect your AHJ would be happier with something that looked like that link, rather than what you've attached.



Without a contractor - sure.
Without proper engineering? No.
And what you said is basically that they require an engineer to approve/create the plans - which is not an onerous requirement IMO.
The structural portion you may be able to get enough from Ironridge and Quickmount.
The electrical portion you may be able to get enough documentation from Enphase since you're using them. That might be enough to make your AHJ happy. (And if not, it's probably less than $300 to get a plan written for you by someone. A vendor selling you panels, etc might even toss it in as a "free with purchase")

VERY informative post, exactly what i was looking for, much appreciated.
- I'll redo my drawing with more colors if it will make the town inspector happy.
- Rafters spacing is 16", old house, older than me.
Rafters with double dotted lines (Vertical) while rails (Horizontal) with single line..... color will be used in the next drawing for better
- To do: quick mount point installation with spacing between them, 4 quick mount connection per rail.
- One roof per drawing, very good idea.

My house is split level, so the ridge is horizontal next to the chimney, (Will be corrected with color) the valley is between the 2 roofs.

You did open my eyes to so many unclear lines in my drawing.
The link is absolutely great, i'll see if i can include it in my permit app with some modifications

Thank again

Drawing will be updated soon

[GreenTeeCrazy]

Like'em or not, two rules that need to be followed: Rule #1: The inspector is always right. Rule #2, if the inspector is wrong, see rule #1.............................. FWIW, a couple of things I didn't see on your drawings was any reference to wind or seismic loading considerations, or any bolting/screw/fastener details........................................... . Also, sometimes/usually it helps to go to the AHJ before submittal. Often, believe it or not, building depts. can be quite helpful. One big reason they are there is to help ensure safety for not only you, but your neighbors and the rest of the community. They are not out to get you. They have better things to do............................................. You can do pretty much what you want to your property without a contractor's assistance, but only to the extent that what you do follows safe, recognized and allowable practices and applicable building and other codes.

Hi J.P.M., thatns for your comment.
I actually did contacted the town and they have no clue to what is required from a homeowner diy solar installation, they always had contractors doing
the work for the homeowners. as i said before, i do my own repair, upgrade in my home, water heater, gas line, boiler, driveway, fence, generator and so on.
and i always apply for permits and have my work inspected by the AHJ inspector. My famil's safety is my first priority.

I do have more building drawing but in different pc, and i dont have access to them right now. but i did all the calculation for wind, snow load, rafters spacing and more diagrams on setbacks from gutters etc.

I just want to make sure that is the inspector denies my application is because of valid point but not that i didnt hire a PE for their seals and stamps.

sensij, thanks for your input.