9.87 kW Enphase installation - Roof penetration questions
RegGuheert
Solar Expert Posts: 102 ✭✭✭✭
Hi All,
While I am new to the forum, I am not new to PV solar. I previously installed a 2.88 kW off-grid system last millenium, having purchased some of the equipment from NAWS. That system is currently in need of repair, but that is a project for another day. I have also installed several small barn-lighting systems for friends.
Today I am working to complete a 9.87 kW grid-tied system consisting of 42 Sharp 235 W panels with Enphase inverters. Here is a picture showing the installations of the rails on the house:
Looking at the picture, you will see six rails on the left over the garage. These rails will contain six rows of seven panels each, electrically organized as three branches of seven inverters. Over the house on the right is a row at the top with nine panels, a row in the middle with eight panels and two rows at the bottom each with two panels. These will also be electrically organized as three branches of seven inverters.
I am installing a solar breaker panel which is located in the house almost directly below the roof overhang which you see between the left and right sets of rails.
Today, I am weighing different options for how to bring the electricity into the house and how to bring the ground wire out. So here are a few questions:
1) Is there any way to make a roof penetration directly using the wire in the Enphase branch kit? If so, can you please tell me how I would go about doing that?
2) If 1) above is possible, is there a similar approach that can be used to bring the ground out?
3) My preference over a roof penetration is actually to bring all the wires in through the thin wall under the overhang between the two halves of the array. However, this poses its own problems. For the left array, I would have to bring conduit the 3.5 feet from the edge of the array to the wall. I am loathe to do this in the middle of the roof because I imagine the snow and ice will simply rip it off the roof. One thought is to run the conduit up just beyond the peak (out of view from the front) and then run it horizontally on the back side of the roof just below the peak. Does anyone have thoughts or experience on how to do this?
4) Similar to 3) above, the problem with trying to go through that wall when coming from the right half of the array is one of aesthetics. Any thoughts on how to get a conduit around that overhang without it being too ugly?
Thanks in advance for any assistance or advice on this topic!
Reg
While I am new to the forum, I am not new to PV solar. I previously installed a 2.88 kW off-grid system last millenium, having purchased some of the equipment from NAWS. That system is currently in need of repair, but that is a project for another day. I have also installed several small barn-lighting systems for friends.
Today I am working to complete a 9.87 kW grid-tied system consisting of 42 Sharp 235 W panels with Enphase inverters. Here is a picture showing the installations of the rails on the house:
Looking at the picture, you will see six rails on the left over the garage. These rails will contain six rows of seven panels each, electrically organized as three branches of seven inverters. Over the house on the right is a row at the top with nine panels, a row in the middle with eight panels and two rows at the bottom each with two panels. These will also be electrically organized as three branches of seven inverters.
I am installing a solar breaker panel which is located in the house almost directly below the roof overhang which you see between the left and right sets of rails.
Today, I am weighing different options for how to bring the electricity into the house and how to bring the ground wire out. So here are a few questions:
1) Is there any way to make a roof penetration directly using the wire in the Enphase branch kit? If so, can you please tell me how I would go about doing that?
2) If 1) above is possible, is there a similar approach that can be used to bring the ground out?
3) My preference over a roof penetration is actually to bring all the wires in through the thin wall under the overhang between the two halves of the array. However, this poses its own problems. For the left array, I would have to bring conduit the 3.5 feet from the edge of the array to the wall. I am loathe to do this in the middle of the roof because I imagine the snow and ice will simply rip it off the roof. One thought is to run the conduit up just beyond the peak (out of view from the front) and then run it horizontally on the back side of the roof just below the peak. Does anyone have thoughts or experience on how to do this?
4) Similar to 3) above, the problem with trying to go through that wall when coming from the right half of the array is one of aesthetics. Any thoughts on how to get a conduit around that overhang without it being too ugly?
Thanks in advance for any assistance or advice on this topic!
Reg
Comments
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Re: 9.87 kW Enphase installation - Roof penetration questions
Here is a shot of my roof electrical penetrations for 8 strings of DC, I assume the code guys would be OK with it on the AC side of your enphase stuff too. -
Re: 9.87 kW Enphase installation - Roof penetration questions
Looks like all the panels will be facing the same direction. At $210 per enphase (hosts pricing) and 42 of them = $8800.
2 x Sunny Boy 5000 = $5900.
Why would you choose enphase? -
Re: 9.87 kW Enphase installation - Roof penetration questions
Thanks, Dave! This type of power entry is one option I am considering. The main drawback to this is the aesthetics and/or shadowing of this approach. I only really have the choice of positioning this above or beside the array. If it above it (on the back side of the house, really), I may be able to hide this if it is not too tall. If it is beside the array, then I'm somewhat concerned about running any wires horizontally along the roof far enough to avoid shadows. Do you know what the minimum allowable height for this type of entry device is?solar_dave wrote: »Here is a shot of my roof electrical penetrations for 8 strings of DC, I assume the code guys would be OK with it on the AC side of your enphase stuff too.
One question about the picture: Can I assume that the electrical wires go straight down into the roof and that the tan pipe shown going to the left is coming from the solar water heater behind the electrical equipment? -
Re: 9.87 kW Enphase installation - Roof penetration questions
Basically, I'm sold on Enphase's microinverter approach versus the traditional string approach. Here are the key factors in my decision:Looks like all the panels will be facing the same direction. At $210 per enphase (hosts pricing) and 42 of them = $8800.
2 x Sunny Boy 5000 = $5900.
Why would you choose enphase?
1) Shadowing/Production: While I will have very limited shadowing in my installation, there will be some in the mornings. The worst shadow should occur on the panel at the extreme right side of the 8-panel row on the right-hand roof. That panel will have some severe shadows until late morning. All other panels will be without shadows long before that one, in my estimation. As a result I would expect less overall production by using two string inverters than one microinverter.
2) Reliability/Availability: The reason my old off-grid array (shown as my avatar) is not on the roof is that I expected to have some issues with it and I did not want to spend more time on the roof than necessary. I was right in that case and I am glad with the decision. In the case of a grid-tied system, I think it makes sense to put the system on the roof, for a variety of reasons, cost included. But in order to justify that, I wanted a system that I can "set and forget." I believe the microinverter system has the best chance to meet that requirement. Just looking at MTBFs, I come up with the following for a 20-year period (assuming both are designed for about a 20-year life):
- 42 PV panels with 600-year MTBF: I should expect one failure approximately every 14.3 years. At the end of 20 years, I should expect to have about one PV panel failed.
- 42 microinverters with 331-year MTBF: I should expect one failure approximately every 7.9 years. At the end of 20 years, I should expect to have about two microinverters failed.
- 2 string inverters with 220,000-hour MTBF: I should expect one failure approximately every 12.6 years. At the end of 20 years, I should expect to have one string inverter failed.
By this simple analysis (which assumes no catastrophic failures), I should expect to lose either 1/2 or the entire array after 20 years with string inverters, depending on whether the PV panel and inverter fail on the same or different arrays. I should expect to lose less than 10% of the array in the same 20 years with microinverters.
In the case of the string inverters, the failure will be so significant it would not be easy to ignore, though the repair might be complicated due to the inavailability of suitable replacement parts. (Ask me how I know!) In the case of the microinverters, I could easily choose to ignore the failures and would not experience a huge loss of production.
3) Diagnostics/Repair: My old array consisted of two sub-arrays feeding two separate charge controllers. The extent of the diagnostics equated to looking at the production of the two sub-arrays and seeing if they are different. If they are different, the question became "What is wrong?" This made diagnosis and repair somewhat daunting, as it would then require significant time and effort, during the daytime only, to go out and find the culprit. While that was a big task for my old rack-mounted array, it is quite prohibitive on a 40-degree pitch roof! By comparison, with microinverters I can easily observe the instantaneous and historical production of *each* inverter and panel to try to determine what is working or not. Some failures will result in diagnostic codes being sent. At that point, I have a lot of useful information about where the failure is and could then easily decide if the repair is warranted or not.
4) Ease of installation: Even though there are 40 more inverters to install, I feel the Enphase installation is simpler because only AC wiring is required. DC wiring and all the requisite safety equipment are not needed.
Thoughts?
Reg
ETA: As it turns out, the MTBF I quoted for the Sunny Boy inverters is really for something else. The number I gave is likely too high. However, I will leave it there for the purpose of this discussion. If anyone has believable MTBF numbers for Sunny Boy inverters, can you please provide them? In the meantime, I will include a few quotes from Sunny Boy executives that I found here:
•SMA America, President: “Why focus on higher reliability? Our customers worry only about first-cost. In any case, it’s more cost-effective to just replace the inverter in 10 years.”•SMA, Head of Solar:“A 20-year lifetime is not possible.”•Fronius, Head of Sales (Germany):“Inverter MTBF may reach 12 years by 2015. A 20-year lifetime can’t be achieved.” -
Re: 9.87 kW Enphase installation - Roof penetration questionsRegGuheert wrote: »<snip>
Do you know what the minimum allowable height for this type of entry device is?
One question about the picture: Can I assume that the electrical wires go straight down into the roof and that the tan pipe shown going to the left is coming from the solar water heater behind the electrical equipment?
I don't know the allowable min height is.
yes
The big tans there are the solar hot water insulating wrap and painted per my HOA requirements.
That weather-head setup is flashed above the roofing and goes straight into the attic to the DC breaker setup. -
Re: 9.87 kW Enphase installation - Roof penetration questionsRegGuheert wrote: »SMA, Head of Solar:“A 20-year lifetime is not possible.”•Fronius, Head of Sales (Germany):“Inverter MTBF may reach 12 years by 2015. A 20-year lifetime can’t be achieved.”
And yet 40 enphase will last how long ??? Sorry, there is so much hype over the enphase MTBF and their testing, I can't quite belive it.
MikePowerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister , -
Re: 9.87 kW Enphase installation - Roof penetration questions
So far, looks good. I'm sure most here would appreciate seeing more pics.RegGuheert wrote: »Today I am working to complete a 9.87 kW grid-tied system consisting of 42 Sharp 235 W panels with Enphase inverters. Here is a picture showing the installations of the rails on the house
What do you mean by "directly"? You will need some sort of junction box or conduit to protect the penetration of the roof or wall. Have a look at Soladeck roof boxes which would work very well for your install.RegGuheert wrote: »1) Is there any way to make a roof penetration directly using the wire in the Enphase branch kit? If so, can you please tell me how I would go about doing that?
If using a Soladeck or similar, you'd bring the ground down in the same box.RegGuheert wrote: »2) If 1) above is possible, is there a similar approach that can be used to bring the ground out?
IMO, using the Soladeck enclosures would be the way to go and you'd keep them under the panels and out of the snow. Otherwise, you can run the strings up to the top and then across the roof in conduit. You'll probably need some junction boxes mounted on the rails so you can extend the pigtails of each string to reach.RegGuheert wrote: »3) My preference over a roof penetration is actually to bring all the wires in through the thin wall under the overhang between the two halves of the array. However, this poses its own problems. For the left array, I would have to bring conduit the 3.5 feet from the edge of the array to the wall. I am loathe to do this in the middle of the roof because I imagine the snow and ice will simply rip it off the roof. One thought is to run the conduit up just beyond the peak (out of view from the front) and then run it horizontally on the back side of the roof just below the peak. Does anyone have thoughts or experience on how to do this?
Use a Soladeck and go straight down though the overhang. Of course, then you might as well go straight into the attic space. Otherwise you'll have to use conduit with a couple 90* pull-throughs.RegGuheert wrote: »4) Similar to 3) above, the problem with trying to go through that wall when coming from the right half of the array is one of aesthetics. Any thoughts on how to get a conduit around that overhang without it being too ugly?
Nice analysis.RegGuheert wrote: »Basically, I'm sold on Enphase's microinverter approach versus the traditional string approach. Here are the key factors in my decision:
Well - it's still too early to tell, but I'm sure that some installers have enough real world experience with them now to know the real-life failure rate. I haven't heard of any, yet, but don't claim to know all the details and probably only know of a half dozen installs that are all fairly new.And yet 40 enphase will last how long ??? Sorry, there is so much hype over the enphase MTBF and their testing, I can't quite belive it. -
Re: 9.87 kW Enphase installation - Roof penetration questions...there is so much hype over the enphase MTBF and their testing, I can't quite belive it.
Mike
"Some things are true whether you believe 'em or not."
The question of Enphase products' durability can be divided
into two categories: the theory; and the practice.
The Theory
If you are skeptical of Enphase's claimed MTBF, why don't
you review their calculation methodology and their "for
experts" white paper on the topic? These documents
are posted on Enphase's website. If you see something
wrong in their approach, bring it forward. It's rather unfair
to publically scoff at their reliability, yet give no reason
(other than a hunch) as to why you feel this way.
To quote from Enphase's documents:
"The MTBF evaluation for Enphase Microinverters
was done theoretically under the guidelines of the Telcordia
SR332 standard. This is the standard that is applied to
determine MTBF for telecommunications equipment deployed in
outdoor environments similar to those in which the Enphase
inverter is installed."
Further, Enphase had a 3rd party engineering firm perform
the calculation.
The Practice
What if the devices fail anyhow? Then, you have to go back
to the manufacturer for redress. Enphase have a 15 year
replacement warranty, and thus the real risk is if Enphase
goes out of business in a manner where no one will honor
the warranty. No one can predict whether a given company
will be around 15 years from now (true also of the SMA's
of the world). While Enphase is a young company, they
have already shipped 400,000 units as of 10/2010, and in
2009 their shipments would rank them as the #2 company
in the inverter market by volume (source: RSS article). This
amount of success, while not a guarantee, suggests that
Enphase has a good chance of being around for the
foreseeable future.
John
Edit: updated the to-date shipments (source: Forbes) -
Re: 9.87 kW Enphase installation - Roof penetration questions"Some things are true whether you believe 'em or not."
The question of Enphase products' durability can be divided
into two categories: the theory; and the practice.
The Theory
If you are skeptical of Enphase's claimed MTBF, why don't
you review their calculation methodology and their "for
experts" white paper on the topic? These documents
are posted on Enphase's website. If you see something
wrong in their approach, bring it forward. It's rather unfair
to publically scoff at their reliability, yet give no reason
(other than a hunch) as to why you feel this way.
If you want a lie, hire a statistician.
It's a hunch developed over 30 years in the aerospace industry. We have a hard time qualifying parts for 10 - 15 year design life in less stringient conditions.
And I belive enphase has a "sworn to secrecy" replacement program, as there is zero info about field failed units. Or they have a Harry Potter casting spells on the thousands of units they ship. It's just not credible there are no field failures, or reports of them on forums.
So I say what I belive, not parroting some PR mumbo jumbo. I read their white paper. While it looks good, it just smells bad.Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister , -
Re: 9.87 kW Enphase installation - Roof penetration questionsRegGuheert wrote: »1) Is there any way to make a roof penetration directly using the wire in the Enphase branch kit? If so, can you please tell me how I would go about doing that?
Reg
Welcome to the Forum, Reg!
Attached is a picture of how my contractor did the roof
penetration for the entire array. I also included a picture
showing how he did the cable management between
micro-inverters.
By the way, after the cable entered the roof/attic, he
ran that inside an interior wall to the circuit breaker box,
with the net result being there are no conduits visible
on the exterior walls of the home.
John -
Re: 9.87 kW Enphase installation - Roof penetration questions
Enphase says their inverters are designed to last over 25 years. I see no problem believing that something designed to process just 3.8% of the power could be made to last five times as long.And yet 40 enphase will last how long ??? Sorry, there is so much hype over the enphase MTBF and their testing, I can't quite belive it.
Mike
The fact is, Enphase accurately KNOWS the MTBF on their units. Because of their ability to track the operation (and failures) of the vast majority of their production units, they are in the unique position to be able to assess the reliability of their units. Also, I will say that the fact that the Enphase inverters do not allow ANY field configuration means that the installations are likely much more uniform than the installations of other company's inverters. The benefit of this is that the stresses on the inverters are likely much better understood and controlled than those in string inverters.If you want a lie, hire a statistician.
It's a hunch developed over 30 years in the aerospace industry. We have a hard time qualifying parts for 10 - 15 year design life in less stringient conditions.
And I belive enphase has a "sworn to secrecy" replacement program, as there is zero info about field failed units. Or they have a Harry Potter casting spells on the thousands of units they ship. It's just not credible there are no field failures, or reports of them on forums.
So I say what I belive, not parroting some PR mumbo jumbo. I read their white paper. While it looks good, it just smells bad.
I will take it farther. Enphase can easily break down the MTBF of their inverters by the various factors that will impact reliability, such as the type and rating of the attached solar panel, the climate, the amount of lightning in the region, etc. This type of information may give important clues to Enphase engineering about what is weakest link in the product.
And then there is the issue of corporate culture. I certainly don't question the SMA executive when he says “Why focus on higher reliability? Our customers worry only about first-cost. In any case, it’s more cost-effective to just replace the inverter in 10 years.” Likely his employees get that message loud and clear. By contrast, listen to what the Enphase CEO Paul Nahi has to say about reliability: "We want to make absolutely certain that once the inverters were installed that the homeowner or the business owner never had to think about it again." He also made a quote (that I cannot find right now) that reliability is not something that can be tested into a product at the end of the process. That statement rings very true to me and I'm sure all of the employees at Enphase get the message that quality is everyone's responsibility. I will say that the SMA executive makes the type of statement that I would expect to hear from the bean counters of large companies with a comfortable market share. OTOH, the statement from the Enphase CEO sounds like the prudent statement of an hungry newcomer working to build a name and a business for themselves. Personally, I prefer to spend my money with the latter.
If you are saying that information about Enphase inverter failures is being suppressed, then I will say that as an Enphase customer I have no knowledge of that effort. Frankly, such a gag order seems almost impossible to enforce. I doubt that someone would be quiet about the failure of a $200 product, particularly if such information would help many others to possibly avoid a very costly purchase. On the contrary, I expect Enphase customers to shout from the rooftops if they experience more than one or two failures in their installation within the first few years. Just in this little community it appears there are already hundreds of Enphase microinverters in service or being installed. Within a year or so, it should become very apparent whether their MTBF numbers are credible or not. -
Re: 9.87 kW Enphase installation - Roof penetration questions
I went to Lowe's today and found a small version of your "Service Entry Head" which is designed to go on 3/4" inch pipe. I'm almost thinking if I could find a small enough flashing I could put this below one of the panels and run three Enphase wires in and the ground wires out. We'll see...solar_dave wrote: »I don't know the allowable min height is.
yes
The big tans there are the solar hot water insulating wrap and painted per my HOA requirements.
That weather-head setup is flashed above the roofing and goes straight into the attic to the DC breaker setup.
Thanks again! -
Re: 9.87 kW Enphase installation - Roof penetration questionsThe fact is, Enphase accurately KNOWS the MTBF on their units.
No, they don't. The have accelerated life testing, which is NOT the same thing. But to the uninformed, it seems to be.
But if nobody is complaining about failures, I see that as:
1) data suppression.
or
2) unbelivablly reliable product.Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister , -
Re: 9.87 kW Enphase installation - Roof penetration questions
I will try to post more as I go.So far, looks good. I'm sure most here would appreciate seeing more pics.
Understood. What I mean is can I get through the roof without having to go into a junction box first?What do you mean by "directly"? You will need some sort of junction box or conduit to protect the penetration of the roof or wall.
I will definitely look at Soladeck, as it sounds like it does exactly what I am hoping to do! Thanks!Have a look at Soladeck roof boxes which would work very well for your install.
If using a Soladeck or similar, you'd bring the ground down in the same box.
IMO, using the Soladeck enclosures would be the way to go and you'd keep them under the panels and out of the snow. Otherwise, you can run the strings up to the top and then across the roof in conduit. You'll probably need some junction boxes mounted on the rails so you can extend the pigtails of each string to reach.
Use a Soladeck and go straight down though the overhang. Of course, then you might as well go straight into the attic space. Otherwise you'll have to use conduit with a couple 90* pull-throughs.
Reg -
Re: 9.87 kW Enphase installation - Roof penetration questions
Accelerated life testing is NOT used to calculate MTBF. It is used to try to predict product life.No, they don't. The have accelerated life testing, which is NOT the same thing.
MTBF is a calculation or measurement of the failure rate at the bottom of the bathtub curve. According to Enphase, their product gets to the bottom of this curve after about 18 days. They are currently monitoring perhaps over 100,000 modules in real time. As such, they have a VERY ACCURATE, on-going, real-time measurement of the MTBF of their products in their actual field environment. No other inverter manufacturer has anything close to this type of data.
Whether they will share this data with anyone is a separate issue. -
Re: 9.87 kW Enphase installation - Roof penetration questions
Thanks, John!Welcome to the Forum, Reg!
Attached is a picture of how my contractor did the roof
penetration for the entire array. I also included a picture
showing how he did the cable management between
micro-inverters.
By the way, after the cable entered the roof/attic, he
ran that inside an interior wall to the circuit breaker box,
with the net result being there are no conduits visible
on the exterior walls of the home.
John
Of course! ACME Conduit Entry! It sounds like a solution even Wile E. Coyote would like!
I'll have a look and see if I can find this product anywhere. Can you tell me what the words are at the top of the box. I can't quite make them out.
Thanks again!
Reg -
Re: 9.87 kW Enphase installation - Roof penetration questionsRegGuheert wrote: »I went to Lowe's today and found a small version of your "Service Entry Head" which is designed to go on 3/4" inch pipe. I'm almost thinking if I could find a small enough flashing I could put this below one of the panels and run three Enphase wires in and the ground wires out. We'll see...
Thanks again!
Like this?
Oatley flashing. Standoffs are 4" rails are 3" tall for scaling. -
Re: 9.87 kW Enphase installation - Roof penetration questions
Nope, you need something to protect the cable and seal the roof as you go through. Can't go through the roof with bare wire unless you want to risk roof leaks and wire damage.RegGuheert wrote: »What I mean is can I get through the roof without having to go into a junction box first?
You'll notice that the Soladeck has an integrated flashing (similar to the Acme product).
You could also "roll your own" with EMT and appropriate oatey flashing and fittings - oatey makes a low profile flashing for this purpose - but depending on how high your panels are off the roof, may be difficult to fit under a panel. -
Re: 9.87 kW Enphase installation - Roof penetration questions
I didn't say I wanted to go through with bare wire. I said I wanted to go through before going into a junction box. Is there some reason I can't use a "service entry head" going through some sort of flashing?Nope, you need something to protect the cable and seal the roof as you go through. Can't go through the roof with bare wire unless you want to risk roof leaks and wire damage.
Yes, I see that!You'll notice that the Soladeck has an integrated flashing (similar to the Acme product).
Yeah, that's what I've been considering before you pointed out the Soladeck. I'll definitely use that as the reference point in my considerations!You could also "roll your own" with EMT and appropriate oatey flashing and fittings - oatey makes a low profile flashing for this purpose - but depending on how high your panels are off the roof, may be difficult to fit under a panel. -
Re: 9.87 kW Enphase installation - Roof penetration questions
Yes!!Like this?
Thanks! I don't have standoffs, so I'm still not sure it will fit. Now I'm wondering if there are any low-profile flashings. The Oatey ones I saw at Lowe's are huge!Oatley flashing. Standoffs are 4" rails are 3" tall for scaling. -
Re: 9.87 kW Enphase installation - Roof penetration questionsRegGuheert wrote: »Yes!!Thanks! I don't have standoffs, so I'm still not sure it will fit. Now I'm wondering if there are any low-profile flashings. The Oatey ones I saw at Lowe's are huge!
These are oatey 11830, perhaps 2" tall. I'm in Arizona, so I need the standoffs to get good airflow under the panels. -
Re: 9.87 kW Enphase installation - Roof penetration questionsRegGuheert wrote: »ACME Conduit Entry! It sounds like a solution even Wile E. Coyote would like!
I'll have a look and see if I can find this product anywhere. Can you tell me what the words are at the top of the box. I can't quite make them out.
ACME makes everything, except good traps for Road Runners. ;-)
I'll see if I can get a better picture of the box top tomorrow. It's
too dark right now to climb back up on that roof!
John -
Re: 9.87 kW Enphase installation - Roof penetration questionsACME makes everything, except good traps for Road Runners. ;-)
I'll see if I can get a better picture of the box top tomorrow. It's
too dark right now to climb back up on that roof!
John
http://www.we-llc.com/ACE.html
Here is another thread that discusses pass through
http://forum.solar-electric.com/showthread.php?t=6608 -
Re: 9.87 kW Enphase installation - Roof penetration questions
Yes - service entry head would work very well. Not too different than using EMT/flashing - just different parts.RegGuheert wrote: »Is there some reason I can't use a "service entry head" going through some sort of flashing? -
Re: 9.87 kW Enphase installation - Roof penetration questionssolar_dave wrote: »
That is TOO MUCH...ACME box from "Wiley Electronics?" LOL
John -
Re: 9.87 kW Enphase installation - Roof penetration questionsThat is TOO MUCH...ACME box from "Wiley Electronics?" LOL
John
gotta love it, simple google!
In case you missed it
http://forum.solar-electric.com/showthread.php?t=6608 -
Re: 9.87 kW Enphase installation - Roof penetration questions
Agreed. I would greatly prefer to avoid any junction boxes on the roof because then I will be left with only the locking connectors on the inverters and the ground connections out there. All other interconnects will be down in my attic which is very accessible.Yes - service entry head would work very well. Not too different than using EMT/flashing - just different parts.
So I'm still not sure, does anyone know for sure whether or not the cable that comes in the branch kit for the Enphase inverters is rated for use in a conduit? If not, then a junction box on the roof is imperative. If so, I will probably go for the service entry head.
One other question: Assuming the Enphase cables are conduit-approved, would it be OK to seal around the wires where they enter the conduit so there is no possibility for water to get in through the pipe? If so, what type of sealant is recommended for such a task? I would like to use something which would not dissolve the insulation of the wire, but would create a good seal and could last on the roof for a very long time. Perhaps the stuff I used under the L-feet on the rails would be fine, but I'm not sure.
Thanks!
Reg -
Re: 9.87 kW Enphase installation - Roof penetration questions
I had five roof penetrations. Here is a link to the picture of the parts prior to installing. It is a 1" utility drop. I run the Enphase branch plus the 6AWG ground wire. I had five drop downs because of the five different panel arrays I had.
I used Oatly flashing (Al) and placed them UNDER the panels so you can't see them.
Just make a drip loop and water will not enter. Plus they are under the panels anyhow.
Each one has 3-4 holes, so you could run one ground wire and three Enphase drops with one head, might have to check the fill calculations though.
On the inside each drop down is attached to a 2X4 member with two straps which secures it. The Enphase drops down to a junction box where it is connected to the wire run(s).
Oh, a note, the coupling it to get to the right OD for the flashing. I got the flashing bulk on-line: Oatey 12920 Flashing $3.85
Cheap, effective and easy. -
Re: 9.87 kW Enphase installation - Roof penetration questions
Any time you have a wire entering/leaving conduit, you need to use a strain relief to avoid abrasion.RegGuheert wrote: »One other question: Assuming the Enphase cables are conduit-approved, would it be OK to seal around the wires where they enter the conduit so there is no possibility for water to get in through the pipe? If so, what type of sealant is recommended for such a task?
There are water proof strain reliefs which use a compression fitting which are weather proof (but it's still a good idea to keep them out of the elements as much as possible). You just need to find the right one that fits your conduit and wire(s). -
Re: 9.87 kW Enphase installation - Roof penetration questions
Thanks for the details on how you did this! I've been reading about your installation for the last month or so. Excellent work!I had five roof penetrations. Here is a link to the picture of the parts prior to installing. It is a 1" utility drop. I run the Enphase branch plus the 6AWG ground wire. I had five drop downs because of the five different panel arrays I had.
I used Oatly flashing (Al) and placed them UNDER the panels so you can't see them.
Just make a drip loop and water will not enter. Plus they are under the panels anyhow.
Each one has 3-4 holes, so you could run one ground wire and three Enphase drops with one head, might have to check the fill calculations though.
On the inside each drop down is attached to a 2X4 member with two straps which secures it. The Enphase drops down to a junction box where it is connected to the wire run(s).
Oh, a note, the coupling it to get to the right OD for the flashing. I got the flashing bulk on-line: Oatey 12920 Flashing $3.85
Cheap, effective and easy.
The service entry head that you are using looks like the ones that I picked up, only 1" instead of 3/4". I'm still not convinced that these will keep the water out. Yes, they face downward and, yes, they are under the panel. However, there can still be condensation on the wires from humid air or mist (like you get in WA often!) and my concern is that it would run down into the junction box and collect there. Did you do anything to prevent this? Are my concerns unfounded?
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