Need advice on drawings

[GreenTeeCrazy]

Here are the .doc files for th eproposal work:

[GreenTeeCrazy]

Updated diagrams

One more time i need any suggestions or modifications to my drawings.

here are the updated files, they seem more professional than kindergarten ones.

[Naptown]

Make them point out the provision in the codes. You have a right to see the written code.

[Naptown]

The code says 18 " if both sides of valley have panels. If only one side than you can go right to the valley.
That whole code as I read it comes from a memo from the chief building inspector. I could find no county council bill adopting that code provision into law.
You may want to file an appeal and see where it goes.
I had the same issue in Annapolis where they were enforcing the setbacks but we're on the same fire code as harford. I filed an appeal and they dropped it and approved it 2 days before the hearing.

[JFinch57]

I was also told by Harford County MD that they need 18" from all valleys. That would only make sense if you had panels on both sides but I didn't ask further. Also, tried to attach my approved line diagram that I did on Visio but there is no button!

[Naptown]

Correct! Harford County. The way the lady at the permit counter explained it to me was the entire perimeter of the array needed the 3 feet of set back. If that is the case, it greatly limits me. If I go with 325 watt panels I can just barely squeak by with 32 panels. I was hoping to be around 12kw and go the level two route with BGE.

Their website says they have adopted the 2013 Maryland state fire code which is basically the NFPA-1-2012
The state code specifically exempts one and two family homes from the fire code. That said they are basing that on a local ammendment which takes the exclusion out ( the exclusion is at the beginning of the code on page 3 I believe.)
Or it could be the IRC which gives you s choice of pathways.

[inetdog]

Correct! Harford County. The way the lady at the permit counter explained it to me was the entire perimeter of the array needed the 3 feet of set back. If that is the case, it greatly limits me. If I go with 325 watt panels I can just barely squeak by with 32 panels. I was hoping to be around 12kw and go the level two route with BGE.

I would look at the exact text of the local rule to confirm that you need the 3' clearance on the downhill side over the eaves too.
Then see whether there is a procedure for the fire department to waive some of that requirement if there is another way (like other side of roof peak) to ventilate the same attic space safely.

[Smitty]

Correct! Harford County. The way the lady at the permit counter explained it to me was the entire perimeter of the array needed the 3 feet of set back. If that is the case, it greatly limits me. If I go with 325 watt panels I can just barely squeak by with 32 panels. I was hoping to be around 12kw and go the level two route with BGE.

[Naptown]

You must be in Baltimore or harford county.
They are the only ones I know of that
Enforce those rules. Most of the state is on the state fire code which exempts one and two family he's from that rule.
However if they are referring to the IRC you can do the 3 feet at each end OR a 3' path in the center. In either case the path cannot be over a window or door.

[GreenTeeCrazy]

GreenTee, I just came from my building permit dept here in MD. Here I must have a building permit for mounting the array first, then the electrical permit after the first permit is approved. They did mention the 3 feet perimeter if, heaven forbid, there is a fire and the firefighters need to walk on the roof. I will be stealing your drawings to help with mine . I too do EVERYTHING on my property and have it approved by my licensed friends for the respective discipline. I sure do learn a lot that way and it keeps the County (who by the way is extremely helpful) happy. Thanks!

please help yourself to my drawing but be careful as i have too many mistakes in their.

In my town, we need 2 permits, 1 for zoning dept and 1 for building, I'll find out about the 3 feet setback once i file the building permit.

Its always nice to have a friend who has some licenses

[GreenTeeCrazy]

@samotlietuvis,
So true, I am getting a very positive attitude from my town inspector.

[Smitty]

GreenTee, I just came from my building permit dept here in MD. Here I must have a building permit for mounting the array first, then the electrical permit after the first permit is approved. They did mention the 3 feet perimeter if, heaven forbid, there is a fire and the firefighters need to walk on the roof. I will be stealing your drawings to help with mine . I too do EVERYTHING on my property and have it approved by my licensed friends for the respective discipline. I sure do learn a lot that way and it keeps the County (who by the way is extremely helpful) happy. Thanks!

[GreenTeeCrazy]

Thanks everyone, I am still working on it. all tips are welcome.

@sensij,
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.

I got what you are saying here. Thanks

[tehan]

Yeah, I definitely don't bat 1.000, but this one is a hanging curve.



This is right. Once you get up to commercial scale (>125 A), there are actually breakers that are rated for continuous load circuits at 100% of nameplate, and code has an exception that allows those to be used without the 1.25 factor. See this white paper for a primer.

Checked and you are right. Dang, 1.000 it is. Kinda odd though, because derating a breaker is more about nuisance prevention than safety so you wouldn't necessarily think it should be a requirement. Mind you, I've seen enough people fix a frequently tripping fuse with a nail to know that a nuisance can easily become a hazard!

[sensij]

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!

Yeah, I definitely don't bat 1.000, but this one is a hanging curve.

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/2015/02/1...erter-breaker/

This is right. Once you get up to commercial scale (>125 A), there are actually breakers that are rated for continuous load circuits at 100% of nameplate, and code has an exception that allows those to be used without the 1.25 factor. See this white paper for a primer.