How to get wires from PV through roof?

JDR*energy

Does anyone have pictures of how their wiring transitions from the roof to the inside?
It seems you would need a pretty large roof penetration to run the conduit or cables directly through the roof. If you run the conduit/cables over the side of the roof or down over the gutter, that seems to be pretty ugly.

I don't really have a problem with the roof penetration since it's a detached uninsulated garage. I have easy access to the inside of the roof.

Am I missing something here?

Thanks!

mike95490

Re: How to get wires from PV through roof?

My guys just drilled a hole thru the roof, and put a roof jack (pipe gasket) over the conduit. They ran the conduit down the wall, and then into the garage.

jza80

Re: How to get wires from PV through roof?

Same basic thing here, they drilled through the plywood underlayment, and replaced a tile with some metal flashing that is used for narrow vent stacks, flattened down under the panels. The conduit was 3/4" ID.

Here's a pic, you can just see the flashing in the circled area:

newenergy

Re: How to get wires from PV through roof?

mike90045 wrote: »

My guys just drilled a hole thru the roof, and put a roof jack (pipe gasket) over the conduit. They ran the conduit down the wall, and then into the garage.

Yep, after you drill the hole and put the piece of conduit through, seal it with some kind of roofing sealant like Henry's, and then use some flashing. On a comp shingle roof you might use something like Oatey 11830.

niel

Re: How to get wires from PV through roof?

jza80,
i see the shading from that tree encroaching on some of your pvs. hope that isn't a problem for you.

System2

Re: How to get wires from PV through roof?

niel wrote: »

jza80,
i see the shading from that tree encroaching on some of your pvs. hope that isn't a problem for you.

OUCH! The shadow is already at the edge of the PV's. This doesn't look good for the future of your project at all.
With any string of series wired panels, shade even a small part of one panel. will not only shut down that panel, but also the output from the string is basically killed. Like the old Christmas tree series wired lights - - one goes out, they all go out. Trees have a nasty habit of growing.
Wayne

JDR*energy

Re: How to get wires from PV through roof?

Thanks jza80 for the picture. I guess I feel better now about cutting a hole in my roof!

Wayne, it's not all doom and gloom.. Who knows what time of day that picture was taken... It doesn't look like high noon judging by the angle of shade on the chimney next door. Besides.. isn't that what they made chain saws for?!? Or if it's a neighbors tree, just refer to the law:

News: Solar energy trumps shade in California prosecution of tree owner

jza80

Re: How to get wires from PV through roof?

jza80,
i see the shading from that tree encroaching on some of your pvs. hope that isn't a problem for you.

Good catch, that photo was taken about 4:00 in November and the edge of shade was about to hit the lower edge panel.

Not a problem anymore, a substantial tree trim was part of the plan. Once the system was up I was able to closely identify which branches and how much length was intruding and needed to be trimmed.

Telco

Re: How to get wires from PV through roof?

Holy cow, the trees were there first. That's wrong, that someone else can make a change to their property while you do nothing to yours, and suddenly you're a criminal. That means your neighbor in California could potentially put solar panels along the ground on the property line and sue to make you tear down your house. I mean, if it's OK to make you tear down a tree, why not a tree product?

niel

Re: How to get wires from PV through roof?

Telco wrote: »

Holy cow, the trees were there first. That's wrong, that someone else can make a change to their property while you do nothing to yours, and suddenly you're a criminal. That means your neighbor in California could potentially put solar panels along the ground on the property line and sue to make you tear down your house. I mean, if it's OK to make you tear down a tree, why not a tree product?

though i agree with you that this is wrong and that in pa they would not allow such to be, i think i can say that they are looking at it like the old days when somebody upriver would dam up a river depleting a resource from going downstream. if (didn't read link here) it is the same case with redwood trees doing the blocking then i would think that california would not stop at your home as they may deem somebody in a valley on the north side of a mountain to be unduly denied solar and make somebody tear down the mountain. i could see it if after you placed your pvs that somebody came along and deliberately blocked the sun that there may be a civil suit for the investment you made, but they can't tell the owner he's not allowed to place something there on his property like a home or even trees for that matter imho.
edit to add: here in pa the branches and leaves that are from a tree growing on one property extending over the property of another becomes the property of the other to do with as they deem proper even if it kills the tree. it is, to be clear, only that portion of the tree which is over the other property that can be deemed part of the other property as the other property owner cannot touch what is not on or over his own property. if the branches overhanging the other property are cut off without going over or on the property the tree was growing on, then it is perfectly legal here and as said, even if it kills the tree. simply put, if it's over your property it is yours.

System2

Re: How to get wires from PV through roof?

What does the NEC say about running the PV wires through the roof? Looking at the PV Power Systems and the 2005 NEC: Suggested Practices, it says:

The code requirement that the PV source and output conductors be kept outside the building until the readily accessible disconnect is reached indicate that these conductors are to be treated in a manner similar to ac service entrance conductors [690.14]. First response personnel are less likely to cut these energized cables since they are on the outside of the building. The 2005 NEC allows PV source and output circuits inside the building providing that they are installed in a metallic raceway [690.31(E)].

Is EMT considered a metallic raceway?

Solar Guppy

Re: How to get wires from PV through roof?

Yes, EMT is required inside the structure for the PV wires

JDR*energy

Re: How to get wires from PV through roof?

Solar Guppy wrote: »

Yes, EMT is required inside the structure for the PV wires

the Grey PVC isn't allowed for inside? I'm doing a detached garage.. I didn't realize it had to be in a conduit... It probably doesn't matter at all for me since there are plenty of romex wires clearly visible all throughout my garage for lights/switches and receptacles.. they were all there when I moved in.

It would seem odd that I have 120VAC running all around exposed, then put low voltage DC in a conduit.

in the 70's my house used to be a hair salon.. with all of the crazy electric in my house (and garage), there is probably 60% that doesn't meet NEC codes.

Solar Guppy

Re: How to get wires from PV through roof?

AC has breakers to handle faults, a wiring fault in solar panel to disconnect run has no such protection and hence must be in a fire proof conduit ( PVC would allow a burn thru and actually be a fuel for the fire )

Its not optional, its a requirement. if you install solar and choose not to follow the NEC, your insurance would likely not pay off if there is a fire, not the best judgement call.

newenergy

Re: How to get wires from PV through roof?



That's me pulling the wire.

JDR*energy

Re: How to get wires from PV through roof?

Solar Guppy wrote: »

Its not optional, its a requirement. if you install solar and choose not to follow the NEC, your insurance would likely not pay off if there is a fire, not the best judgement call.

Yeah I guess that is a good point...with AC the breaker is AT the power source.. with PV the first interrupt may be many feet away...

This little battery charging project I have is getting very expensive. Between conduit, mounting hardware, 8AWG wire, disconnects, fuses, etc.. I think I'll have more money in "supporting hardware" than I do in half of my main components!

I'm so glad I haven't broken out my calculator to see what the ROI is on this project

newenergy

Re: How to get wires from PV through roof?

I have a solar panel mounted on my truck which charges tool batteries and I'm making a little illuminated sign too.

I'm also afraid to add up the costs, but it's a business expense so I'll have to.