Just begining DIY project

[paulcalif]

I'd like to DIY install solar on my Riverside California home.

I've done a little research, need to do more. Hopefully I haven't already made a big mistake. I purchased 12 solar panels. The panels are Longi LR4-60HBP-350M. Are these ok?

I don't want to change out my service/breaker panel unless I have to. It's Outside, flush mounted, in stucco. My panel appears to be rated for 125amps and currently has a 100Amp main breaker. I read somewhere that I can change out the 100Amp for a lower amperage breaker, say an 80Amp. I believe that would allow me to supply a maximum of 45Amps from solar. Is that correct? Or can I go over that 125 amp rating? I think I read 120% (I need to start taking notes :-(.

I have a lot of open roof area on my single story 1750sqft home. Unfortunately, I don't have a South facing roof. I have 2 large areas, one facing east, the other west. Will that work?

The roof is tile. I've seen several videos on how to install the rail roof hooks. Every one of the videos shows a different type of hook and different ways to seal them to the roof. Some use no flashing. Some use felt, some use a rubber like flashing and some use metal. How do I figure out what kind of hooks I need? Will all of the hooks made for tile work? Is there a particular brand of hooks and rails that are most commonly used? Does it depend on the type of tile I have?

I plan on using Enphase micro inverters, but only because those seem to be the most popular and readily available. Thinking 7 series since my panels are only 350W. Are they a good choice? Is it safe to buy used? Will the city allow used? Or should I just go new?

I know each panel gets an inverter, and that they link together. I'm fuzzy on how that power gets down to the panel below. I know I need a water tight connection box on the roof to connect the wire from the inverters to the wire going through the attic and finally outsider. I'll need some kind of a water proof roof penetration. Can I use emt through the attic? Could I use Romex without conduit? (Can't put romex in conduit, but I could put junction boxes in the attic?? Or do I need to run rigid?
Once outside (stucco), do I need riged or can I run emt? Am I only running the power cables or is there also a logic cable that must be run?

Outside, I know I need a disconnect, and a "magic Enphase box" (need to learn a lot more about that).

Reading several posts on this site, I've learned that I should plan, get the plans approved and then purchase the components. Oops, should have waited on the panels. Got them for $140ea. cash, which I've since learned is about full retail. They're new from an installer that went out of business. If I had it to do over, I would have purchased from a reputable supplier with a warranty (and a receipt).

Any advice will be greatly appreciated, even just a point to some good info. I'm old but still in pretty good shape. Hiring this out doesn't make financial sense. I won't live long enough to pay it off with the savings. Thanks in advance.

Oh, and the house has a whole house generator with a separate breaker panel and an automatic switch. There is a problem with it, but that's another post for another forum

 

[12VoltInstalls]

So you want to just power your home when the sun is up? Or get ‘paid’ to feed the grid? It doesn’t sound like you wish to disconnect from the grid or have solar as a backup (no batteries and using microinverters)
I believe you’ll need to use metallic conduit from the panels/microinverters on the roof and through any interior spaces to whatever exterior junction boxes, breaker panels, or control device boxes you plan to utilize. Not sure about Cali permitting plastic conduit on the exterior fwiw but many places that’s fine.

Could I use Romex without conduit? (Can't put romex in conduit, but I could put junction boxes in the attic??

Is it a code thing to not run romex in conduit?!
Having said that, I’d use the appropriate thhn in conduit myself; simpler, easier to plan the pull, and smaller conduit than ‘bulky’ romex. 500ft spools are usually less costly for the same number of conductors and the conduit will be a bit less spendy.

If the junction boxes are “accessible” (not buried with no access) they can be installed in the attic. I believe NEC requires solar cables to always be in conduit anyway.

the house has a whole house generator with a separate breaker panel and an automatic switch

Is that also a 100/125A panel? That might be a consideration for integration.

I don’t have any experience with microinverter systems so I can’t offer more than these observations.

read somewhere that I can change out the 100Amp for a lower amperage breaker, say an 80Amp. I believe that would allow me to supply a maximum of 45Amps from solar. Is that correct? Or can I go over that 125 amp rating? I think I read 120% (I need to start taking notes :-(.

No idea how this ‘computes’ since 4200W at 120V is only 35A without factoring for temp or equipment efficiency losses or anything.

The idea of a solar power system without batteries and a central inverter/ATS/offgrid capability has not really been anything I’ve spent any time on. It’s just not in my dichotomy. I understand its appeal for some city residents but the idea of anything over 5-7 year ROI without a provision for autonomy does not compute for me. Gridtie with feedback/payback with offgrid capability makes some sense (especially with my welders, bigger compressor, and iron tablesaw) but without factoring battery costs- not being grid vulnerable is not much different in cost over being grid vulnerable when one factors for time and the price of entry less any ‘credits’ or other paybacks.

I will say… growing up in New Hampshire and now living in Vermont for a number of years; just looking at the proximity of what I assume is ‘neighboring houses’ your sat photo stresses me out LOL

 

[chrisski]

Most of the your questions are permitting and would be difficult to answer. The authority with jurisdictions AHJ has likely adopted 2020 NEC code with local exceptions, so getting someone from your county or town to help a DIY would be difficult. That’s why I decided on a contractor to install.

I purchased 12 solar panels. The panels are Longi LR4-60HBP-350M. Are these ok?

Recommend holding off on more purchases until you have a good plan, and approved permit. For my RV, I had some headaches about getting stuff too early and having to design the system around that.

Is it safe to buy used?

If you buy used, this is ineligible for a tax credit.

Can I use emt through the attic?

Look at installs in your area. Typically in central AZ, I see external conduit on the roof and wall to an external inverter next to a main electrical panel. The conduit is painted to the March roof.

 

[pvgirl]

If you are doing a grid tied system, with no battery, you should read up on the net metering program in your area, being in CA you will most likely be subject to NEM 3.0 which changes the payback of solar vs older net metering programs. Used Enphase micro inverters will not be covered by their warranty. The site PVWatts https://pvwatts.nrel.gov/ can help estimate production based on the angle and direction of your roof.

Before we get into the details of wiring, inverters, etc the first question is what is the goal of your solar system?

 

[paulcalif]

Wow, what a great forum, you replied fast!! Thanks everyone!

I hadn't considered used equipment not being eligible for a tax credit. I may not get much of a credit anyway as I rent the house out most of the time on Airbnb.

I should have mentioned that I don't want the hassle and storage of batteries (so no battery storage This will be a grid tied system only, no backup. I don't plan on "oversizing" the system by much, at least not at this point. I'll need to look into the metering program as suggested, plus without changing out my breaker panel I'm limited on how much power I can produce. I never even considered the ampere capacity of the second panel for the whole house generator, that could kill my whole plan. My calculations were to figure out the maximum allowable amperage to my existing panel. Maximum for the panel is 125Amps, with the current (no pun intended) 100Amp breaker, I could only produce 25 Amps (125 Amps max-100amp breaker), but if I swapped out the 100AMP Main for an 80 Amp, I could do 45 Amps (125-80). If I'm allowed to go over the panel rating by 20% (not sure where I got that idea) then 125 + 20% = 150Amps. Then 150-80 would be 70 Amps I'd be allowed to produce. That's where my numbers came from. Looking at existing instains in my area is a good idea. There is a whole track of newer homes close by that all have solar. Solar is required on new home construction at least in this area. As far as conduit goes, I've done some commercial electrical installations of fire suppression systems. On exterior walls we were required to have ridged conduit below a certain height, emt in the overhead and no exposed pvc. I think schedule 80 pvc may be ok for residential, but I'm not sure. If pvc is allowed, that would make this job a LOT easier. Sounds like I'm going to have to try to get in contact with the City of Riverside Building Department on some of my questions. Oh, reading up on setbacks I read that there are different rules if you have fire sprinklers, anyone know if that's true. I think I have plenty of roof space anyway, but was just curious.

Thanks again everyone

 

[pvgirl]

On your current panel, with the current main you'd be able to do 9.6kw of solar or 13.4kw if you went to an 80 amp main.

Enphase uses a proprietary wiring system, Q-Cable, with special connectors to link their micro inverters, at one point in the run the wire enters a junction box and changes over to standard building wire. Since these are AC inverter output circuits the special requirements for DC solar circuits don't apply. So you aren't required to use metal conduit inside the building, and can even use romex. Generally you'll want to use metal conduit on the roof. Enphase has their combiner box where all. the circuits from the micro inverters run to, that also has there management and monitoring interface built-in.

 

[paulcalif]

Awesome, that's what I thought and was hoping for. I was planning on one set of panels and only running conduit through the roof. It would be easiest to run romex through the attic and up to the roof if that is allowed. I would make the connection from the building wire to the proprietary Enphase wire inside a water proof junction box on the roof and connect that box directly to a roof penetration. Or, if it made more sense and is allowed, I could route the Enphase wire through the roof and put a box in the attic. Doing it the latter way I wouldnt need the water proof box on the roof. If it makes sense to have 2 sets of panels, (I'll call them arrays, correct me if I'm wrong), for better sun exposure, I'm assuming I could connect the Enphase wire from both "arrays" to building wire and then connect the building together from each array, to bring it down to the "Combiner" (Assuming correct wire gauge). Or would the building wire from each array have to be run separately?

Man, I did a little research on the NEM 3, what a rip off! According to what I read, not only do they now pay practically nothing for the excess power you produce, but they also charge you differently for the power from the power provider, charging more for the power you use at night! What is the logic to that? Talk about discouraging residential solar. The City of Riverside provides my electricity, so I'm not sure if they are subject to NEM 3??

THANKS FOR THE HELP!

 

[pvgirl]

You'll want a water proof junction box on the roof, there are solar specific ones like soladeck, but any waterproof junction box will do.

 

[12VoltInstalls]

with the current (no pun intended) 100Amp breaker, I could only produce 25 Amps (125 Amps max-100amp breaker), but if I swapped out the 100AMP Main for an 80 Amp, I could do 45 Amps (125-80).

with the current main you'd be able to do 9.6kw of solar or 13.4kw if you went to an 80 amp main.

This makes no sense whatsoever. But I am ignorant with the microinverter scheme. I’m assuming I’m just dumb

If pvc is allowed, that would make this job a LOT easier.

EMT isn’t that complicated, you just don’t glue it together.

 

[pvgirl]

This makes no sense whatsoever. But I am ignorant with the microinverter scheme. I’m assuming I’m just dumb

NEC rules for grid tied solar interconnection, when the interconnect is at a load center, are based on 120% of the panels busbar rating, which the sum of the main breaker rating, and 125% of the inverter output current must be less then, when the inverter breaker is at opposite end of the panel from the main. This is to take self consumption in to account but not overload the bus in the panel.

 

[chrisski]

EMT isn’t that complicated, you just don’t glue it together.

If you don’t glue it, how do you seal from the elements?

 

[12VoltInstalls]

If you don’t glue it, how do you seal from the elements?

There are waterproof fittings. Unless those aren’t code or something?
One building I managed was all EMT for the air handlers on the roof for some reason. I’m not an electrician, i don’t know why. All sleeved compression fittings with a grounding tab.
These fittings are different than those.
But it had a valid occupancy permit.

Many moons ago as a mech/maintenance employee at a ski resort with pools, spas; and with a short stint a few years back as a maint. supervisor at a indoor water park there was often emt with waterproof fittings with various equipment. There was also typical plastic in some places.

 

[chrisski]

There are waterproof fittings. Unless those aren’t code or something?
One building I managed was all EMT for the air handlers on the roof for some reason. I’m not an electrician, i don’t know why. All sleeved compression fittings with a grounding tab.
These fittings are different than those.
But it had a valid occupancy permit.

Many moons ago as a mech/maintenance employee at a ski resort with pools, spas; and with a short stint a few years back as a maint. supervisor at a indoor water park there was often emt with waterproof fittings with various equipment. There was also typical plastic in some places.

I have not yet installed PVC EMT requiring two pieces to be joined, just one short 8’ run. I did not realize compression fittings were available And thought glueing was standard.

 

[goldserve]

You have a center fed panel so I believe 120% rule does not apply. Open an account on OpenSolar and start to design your system. West facing panels are not bad. Get a drawing and approval on the components first.

 

[12VoltInstalls]

I have not yet installed PVC EMT requiring two pieces to be joined, just one short 8’ run. I did not realize compression fittings were available And thought glueing was standard.

EMT = Electrical Metallic Tubing
PVC is not metallic

There are compression fittings specific to pvc as well. But that is only for applications where it’s desired or required as glued fittings are sorta not removable. Glueing pvc conduit is standard