Planning my own PV install, need confirmation on wire/breaker size

Based on my roof size and shape, I need to split the panels up into 4 rows of 4, 5, 6 and 5 panels respectively, mounted in portrait. I can't afford the whole setup in one fell swoop, so I will install each row in phases. As such, each row will have its own trunk cable that feeds into an AC combiner. Each panel will be attached to an Enphase M215. Based on the Enphase formula they use in the manual (max output / 240 x Inverters * 1.25), here is what I came up with for current on each trunk:

Row 1 - 4.48 amps
Row 2 - 5.60 amps
Row 3 - 6.72 amps
Row 4 - 5.60 amps

Given that, I figured I would be safe to use 14/3 from each jbox going into 15a double pole breakers at the combiner. First question, does this seem accurate?

Secondly, from the combiner (and this is where I need the most help), I come up with 22.4 amps. Second question, does this seem accurate?

If the above is correct, would I be safe in running 10 awg wire from the combiner into a 30 or 40 amp double pole breaker in my house breaker panel?

Any help would be greatly appreciated.

Comments

  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size

    How long will those wires be as that would make a difference.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • melvin2345
    melvin2345 Registered Users Posts: 5
    Re: Planning my own PV install, need confirmation on wire/breaker size
    jcheil wrote: »
    How long will those wires be as that would make a difference.

    jbox to combiner - varies on which row, but not more than 35 ft

    Combiner to house (via meter and safety shutoff), not more than 15 ft
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size

    The wire length is not relevant here because the output of the micro-inverters is 240 VAC; there would be no V-drop issue.

    Use Enphase's output current rating times the number of units in each row to get the combined current. I think that's 0.9 Amps each? If so:

    Four @ 0.9 = 3.6 Amps * NEC derating 1.25 = 4.5 Amps
    Five @ 0.9 = 4.5 Amps * NEC derating 1.25 = 5.625 Amps
    Six @ 0.9 = 5.4 Amps * NEC derating 1.25 = 6.75 Amps

    All rows will be well under 10 Amps. Wiring needs to be sized for the maximum current per row, so 14 AWG will certainly handle that. Actual breaker sizing depends on wire size and that means 15 Amp breaker per row. Combined current (output from combiner) is 22.5. This has already been derated at the combiner breakers so further derating is not needed (although some AHJ's may not comprehend this). Nevertheless you have to use wire & breaker capable of carrying the rounded-up current of 30 Amps. This would be 10 AWG and a 30 Amp double pole breaker. 10 AWG will handle 240 VAC @ 30 Amps for 100 feet before the V-drop becomes significant, so no worries there.
  • melvin2345
    melvin2345 Registered Users Posts: 5
    Re: Planning my own PV install, need confirmation on wire/breaker size

    Thank you for the quick response Cariboocoot. I have been reading about every aspect of a PV install for the past couple months so that when spring rolls around I'll have a well devised plan in place. I was pretty sure I had my head wrapped around this portion of it, but it makes me feel better to have someone verify that.
  • SolarPowered
    SolarPowered Solar Expert Posts: 626 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size
    melvin2345 wrote: »
    Based on my roof size and shape, I need to split the panels up into 4 rows of 4, 5, 6 and 5 panels respectively, mounted in portrait. I can't afford the whole setup in one fell swoop, so I will install each row in phases. As such, each row will have its own trunk cable that feeds into an AC combiner. Each panel will be attached to an Enphase M215. Based on the Enphase formula they use in the manual (max output / 240 x Inverters * 1.25), here is what I came up with for current on each trunk:

    Row 1 - 4.48 amps
    Row 2 - 5.60 amps
    Row 3 - 6.72 amps
    Row 4 - 5.60 amps

    Given that, I figured I would be safe to use 14/3 from each jbox going into 15a double pole breakers at the combiner. First question, does this seem accurate?

    Secondly, from the combiner (and this is where I need the most help), I come up with 22.4 amps. Second question, does this seem accurate?

    If the above is correct, would I be safe in running 10 awg wire from the combiner into a 30 or 40 amp double pole breaker in my house breaker panel?

    Any help would be greatly appreciated.

    Enphase M215 12AWG Engage Trunk cable accepts up to 17 panels, following the specs of the inverter, each inverter is a 1 amp MAX multiplied by 1.25 according to NEC you get exactly 21.25 amps, so it requires a 25 amp over current protection. With 16 panels its exactly 20amp over current protection. Micro Inverters up converts voltage from amps converting a 36V or 48V panel and converting to 240V, where as with grid tied string its the opposite down converting voltage from a 500V to 600V max to 240V AC, and supplying higher ampers to the service panel.
    Why are you mentioning rows as if they are strings, instead of group "combined" per engage trunk cable, if the roof pitch is consistent? You should be aiming to maxing out each trunk cable to 16 or 17 inverter/ panels, then starting the next run or array of trunk cable, unless roof pitch is inconsistent.
    From what you are expressing I believe you are way over thinking your system.
    Trunk cable is your combiner for multiple panels combining amps per every 1amp max per inverter, you should just be splicing into a rain proof or NEMA 3 rated splice box, not combining via combiner "until you exceed 4.65kwh from one completed bank of 17 panels maxed at 275 WP" . Regardless, after 25amps dual pole you should be engineering for an additional 25amp dual pole or derate to what ever the smaller configuration is. Your system is so small talking about adding combiner AC boxes just seems ridiculous to me.
    I just designed and engineered a permit set for a client a 7.5kwh emphase system one west bound one south bound, maxed the westbound to 16 panels, and south bound 13 panels. Purchased 1 engage kit, with 29 trunk connectors. Then just used heyco connectors into red dot Thomas Betts rain boxes, ran rigid conduit with 10AWG THHN to west bound and south bound AC square d disconnects, and then used 2 dual pole 20 amp breakers.

    Could you specify 1 amp max per inverter trunk connection, because if not I am reading your language as if its 1.12amps per panel. Also according to your amperage output (assuming its DC), you didn't include a panel spec so I don't know if you are talking AC side or DC side, so if based off your panel stc the M215 is not the correct micro inverter for you to use. Right off the batt even if you were yielding 48V your panels are roughly 60~80 watt panels. M215 is rated for 200~275 watt panels. You need the correct inverter for MPPT to function accordingly. A M215 according to your amperage would just sit in standby, I don't even think you could use an M190 based off that DC amperage if that is infact STC per panel.

    (I.E) My project uses CS6P-260M canadian solar panels VMP 30.1 IMP 8.41. Just off the top of my head without running the calculations. The voltage up conversion requires roughly 7.3amps to get 240VAC, .56 amps are burned up in conversion, the rest is under the 1amp max from enphase's max output spec.

    Just to heed caution for you. You already don't know what you are talking about and if you are trying to push for permits from your Jurisdiction, I wish you the best of luck. My client that I designed and engineered his permit set for, thought he could bypass my permit processing fee's, and thought he could do it himself. After numerous attempts of him not being able to explain his system to the building department that I designed and engineered, he had me go to the building department to get the permit issued.

    Starting January 1st, 2014 NFPA regulations will be strictly enforced in every state, and every local jurisdiction. So also to heed caution if you haven't pulled your permit now chances are because of NFPA set back requirements your system could also be reduced 30~40% than what you think you are expecting from your array.

    The building departments have been cracking down on home owners who are not qualified for build, and are only accepting permits from a architect/engineer certified for solar installations over 5lb.s per sq/ft, or 18" from grade, Class B , Electrician, or Solar contractors. If you are looking to do this permit stuff yourself, I suggest you get in the door with your permit application within the next week, or you will probably be forced having a professional build your system within a 10 year labor warranty against defects. That is if you are looking to collect the tax credits and state rebates in your area.

    I suggest you do a few things.

    For your trunk cable to junction box connections use Heyco cord grip water tight strain reliefs into a standard rain proof RED Dot Thomas Betts Junction Box, that's is a simple as a combiner box gets under 25amps.
    http://www.heyco.com/Liquid_Tight_Cordgrips/pdf/3-01.pdf

    For the splice junction boxes the back of the boxes must be face down and strapped to a dura block roof block, or under neath a roof eve and anchored with a rain tight cover. This is as simple as combiner boxes get, and after combining all the trunk interconnections together I would just use 10AWG THHN with Rigid conduit to your disconnect/service panel, (IF) they are all in the same tilt/angle of azimuth, rule of thumb do not exceed 17 panels per engage trunk cable, if not, more boxes, more disconnects, more breakers.

    http://www.homedepot.com/p/Red-Dot-1-Gang-Rectangular-Weatherproof-Box-S107E/100149426#.Uplb8cTFVzY

    Go to www.dsireusa.org , so you understand the qualifications for the rebates and tax credits, in order to collect, your installation and design needs to be submitted by a qualified professional.
    Invest in an UGLYS electrical guide
    Go to http://www.solarabcs.org/codes-standards/NFPA/, you need an understanding of NFPA rules and regulations.
    Invest in an 2011~2012 NEC, NFPA enforced regulations are going to be published in 2014 NEC

    Now the reason for the NFPA enforcement is because local jurisdictions have roughly 4~6 years to comply to newer guidelines, NEC publications are released every 3 years. Which means when January 1st 2014 rolls around, 2008 NEC will no longer be acceptable by any jurisdiction. In 2011 NEC the setbacks were provided which means in 2014, 2011 NEC is enforceable. 2008 NEC gave lots of leeway on building solar, and had the bare minimums as did NEC 2005. Section 690 of NEC on solar wasn't devised until amended 2008 which was published in mid 2009.
  • melvin2345
    melvin2345 Registered Users Posts: 5
    Re: Planning my own PV install, need confirmation on wire/breaker size
    Just to heed caution for you. You already don't know what you are talking about....

    Wow. Your reading comprehension is awful at best, and your assumptions are way off base.

    Here are the key points you either missed, or didn't understand:

    "I can't afford the whole setup in one fell swoop, so I will install each row in phases."

    This is why I'm doing 4 trunk cables, one for each row of panels. Buying a cut to length trunk cable for each row is cheaper than buying a full cable and capping unused ports. This is also the reason for the combiner box, so that with each new row of panels I install, I can easily integrate them into the full system. I thought this would be pretty apparent from the rest of the information provided.

    "Each panel will be attached to an Enphase M215."

    Given that I referenced the amperage for each row of panels, and specified I was using microinverters, common sense would dictate that I'm referring to the AC side of the system.
    Also according to your amperage output (assuming its DC)

    Clearly, you assumed wrong and the rest of that paragraph is just ramblings.

    For the record, I'm going to be using Toppoint JTM240-60M panels
    Watts (STC) 240W
    Watts (PTC), 240W
    Maximum Power (Vmp) 30.56V
    Maximum Current (Imp) 7.85A
    Open Circuit Voltage (Voc) 37.49V
    Short Circuit Current (Isc) 8.54A
    if you are trying to push for permits from your Jurisdiction, I wish you the best of luck. My client that I designed and engineered his permit set for, thought he could bypass my permit processing fee's, and thought he could do it himself. After numerous attempts of him not being able to explain his system to the building department that I designed and engineered, he had me go to the building department to get the permit issued.

    Well, unlike your client, I am articulate and detailed enough to explain simple engineering to the gentleman who authorizes permits in my county, as well as the representative from the power company who would be overseeing the interconnection process. The power company was satisfied, and the only detail the county wanted further clarification on was exact wire size and breaker configuration I would be using. Which is why I asked this question in the first place.

    As for the rest of your post, you may very well have some useful information.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size

    Let's keep it civil, guys.
    This moderating job is hard enough, especially right now when the whole forum isn't working properly - including the 'edit' function.
  • SolarPowered
    SolarPowered Solar Expert Posts: 626 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size
    melvin2345 wrote: »
    Wow. Your reading comprehension is awful at best, and your assumptions are way off base.

    O.K so let me clarify without mud slinging you.
    melvin2345 wrote: »
    Row 1 - 4.48 amps
    Row 2 - 5.60 amps
    Row 3 - 6.72 amps
    Row 4 - 5.60 amps

    For row 1 how did you get 4.48 amps?
    Row 1 should look like this: 4 inverters @ 1 amp max each is 4X1.25= 5amps over current protection
    Row 2 should look like this: 5 inverters @ 1amp max each is 5X1.25= 6.25amps over current protection
    Row 3 should look like this: 6 inverters @1amp max each is 6X1.25= 7.5amps over current protection
    Row 4 should look like this: 5 inverters @ 1amp max each is 5X1.25=6.25 amps of over current protection

    Enphase makes the math very simple to understand. If you look at the enphase M215 spec sheet it tells you maximum rated nominal current is 1 amp maximum @ 208V, .90amp @ 240V, so your over current protection is the maximum allowable times 1.25. If you actually read through the entire spec sheet you wouldn't of started the thread and asked the question. To be on the safe side the inverter even @240V fluctuates to .95 if you use an ameter to diagnose the actual output, so you could just say its 1amp and multiply by 1.25 to keep it safe and any city building department will say its an acceptable calculation.

    [you need to] read thoroughly through documents. I'm just saying and doing the same things a building department plan checker does. If you are designing your own system you shouldn't of missed that specific data in the spec sheet. It brings into question if you really know your system.
  • melvin2345
    melvin2345 Registered Users Posts: 5
    Re: Planning my own PV install, need confirmation on wire/breaker size
    For row 1 how did you get 4.48 amps?

    I refer you to pages 1 and 2 of the Enphase technical brief titled "Circuit Calculations for the M215 Microinverter" (link). Below is DIRECTLY from the Enphase documentation.

    The formula to calculate the circuit current of a branch is:

    Amps/Branch = Maximum Output Power / 240 x Number of Microinverters

    For example, if the maximum output power is 215 Watts AC and there are 17 microinverters, then:

    215 / 240 x 17 = 15.3 Amps/Branch

    Overcurrent Protection Calculation

    Use the value of 1.25 and the Circuit Current Calculation determine the overcurrent protection value. For example, if the circuit calculation is 15.3 Amps, then:

    15.3 x 1.25 = 19.1 Amps


    So, following the 'very simple math' provided by Enphase, my calculation is:

    215 / 240 x 4 = 3.583

    3.583 x 1.25 = 4.47916 (4.48 Amps)

    As far as why I started this thread, I understand and acknowledge that I don't know everything. I prefer having my conclusions and calculations confirmed by others if I have any doubts.
  • SolarPowered
    SolarPowered Solar Expert Posts: 626 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size
    melvin2345 wrote: »
    I refer you to pages 1 and 2 of the Enphase technical brief titled "Circuit Calculations for the M215 Microinverter" (link). Below is DIRECTLY from the Enphase documentation.

    The formula to calculate the circuit current of a branch is:

    Amps/Branch = Maximum Output Power / 240 x Number of Microinverters

    For example, if the maximum output power is 215 Watts AC and there are 17 microinverters, then:

    215 / 240 x 17 = 15.3 Amps/Branch

    Overcurrent Protection Calculation

    Use the value of 1.25 and the Circuit Current Calculation determine the overcurrent protection value. For example, if the circuit calculation is 15.3 Amps, then:

    15.3 x 1.25 = 19.1 Amps


    So, following the 'very simple math' provided by Enphase, my calculation is:

    215 / 240 x 4 = 3.583

    3.583 x 1.25 = 4.47916 (4.48 Amps)

    As far as why I started this thread, I understand and acknowledge that I don't know everything. I prefer having my conclusions and calculations confirmed by others if I have any doubts.

    That calculation is a "average" operating range, from 215watts. That is not at all a real world scenario, because if you have a 275watt panel for example that would be a 15% loss in power. That math is stating that the inverter using its MPPT aims for that range, hense why it is a M215. However all panels are different with different wattage specifications, and in a PTC condition you can have a panel that exceeds its STC. If you get a really cold day, with perfect angle of incidence the voltage of a panel can exceed its STC, also every panel has its own I.R curve which not one curve from the same name plate badged panel is identical, all panels are different with a slightly different characteristic.

    When it comes to inverters because there is an I.R curve, and that curve never operates the same from day to day, the spec sheet identifies the MAX output rating of the inverter equipment. In the case of enphase for 240V it say nominal max output is .90, however since its under 1/10th of 1 amp you could just say its 1 amp, and multiply by 1.25.

    When ever you build a system its always based on the maximum output that the equipment can perform to.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size

    When ever you build a system its always based on the maximum output that the equipment can perform to.

    Which is limited by the output capacity of the inverter, not by the panel powering it. A 215 Watt micro-inverter can only put out 215 Watts, even if it has a 275 Watt panel on it.
  • SolarPowered
    SolarPowered Solar Expert Posts: 626 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size
    Which is limited by the output capacity of the inverter, not by the panel powering it. A 215 Watt micro-inverter can only put out 215 Watts, even if it has a 275 Watt panel on it.

    That statement is modestly accurate, @ .9amps X 240V is 216watts.
    The spec sheet says however that it has the capacity to output 264V so you take .9amps X 264V= 237.6 watts
    The minimum operating output voltage is 211V, the maximum operating output voltage is 264V.

    The inverters happy average range for "continuous operation" is 215watts

    Its the increase in voltage, while limiting the amperage is what allows for the use of 12AWG conductor for the trunk cable, VS running a higher amperage and up sizing the conductor for the trunk cable to 10 or 8 AWG. After installing trunk cables on my systems I always up size the wire to 10AWG regardless if its a 40' run or a 120' conductor run, because I don't want to lose the higher end voltage that the inverters can produce.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size

    Actually the output Voltage will vary to match the line Voltage. The current will adjust downwards accordingly.

    Also remember the difference between the continuous current rating of a conductor and its peak capacity. This is why NEC derates to 80%. Continuous ratings are used for calculations; the peaks will take care of themselves.

    Nor does a 275 Watt panel produce 275 Watts all day long. In fact it's average output will be about 220 Watts, and the temperature factor means that the panels will be hottest and thus at lowest Voltage when insolation is at maximum.

    No worries here.
  • SolarPowered
    SolarPowered Solar Expert Posts: 626 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size
    Actually the output Voltage will vary to match the line Voltage. The current will adjust downwards accordingly.

    Voltage doesn't have to be matched. Its frequency that has to be matched.

    Think about it. Once a service panel is under load, and the more appliances running in that home drops voltage, amperage is typically not the problem.

    So what you are telling me is if I have every light on in my home, and I power my fridge and heat pumps, lets say hypothetically both poles drop to 105V, which would be 210V under the spec of the enphase it wont want to operate at all? My understanding was that inverting power was to keep voltage levels healthy for a demand no matter the circumstance.

    Lets say there is a duplex or condo there is always a demand for power from the transformer from multiple consumers. What you are telling me is that 264V will never be achievable?
    That makes no sense, the amperage on the inverters are so low voltage matching is moot.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size

    The Voltage of the GTI will match the Voltage of the grid. It has to. And yes if the GTI sense the Voltage on the line is too low it will shut down. It has to. What's more, if the resistance in the wiring is too great and the GTI's output Voltage can rise over its maximum it will also shut down. It has to.

    PV's and thus GTI's are current source power supplies. They will allow their output Voltage to adjust to whatever is found on the grid power (within range) and then supply current up to their maximum power at that Voltage. Anything outside of spec causes them to shut down (anti-islanding).

    And if your power is dropping to 210 Volts you have a real bad problem.
  • SolarPowered
    SolarPowered Solar Expert Posts: 626 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size
    The Voltage of the GTI will match the Voltage of the grid. It has to. And yes if the GTI sense the Voltage on the line is too low it will shut down. It has to. What's more, if the resistance in the wiring is too great and the GTI's output Voltage can rise over its maximum it will also shut down. It has to.

    PV's and thus GTI's are current source power supplies. They will allow their output Voltage to adjust to whatever is found on the grid power (within range) and then supply current up to their maximum power at that Voltage. Anything outside of spec causes them to shut down (anti-islanding).

    And if your power is dropping to 210 Volts you have a real bad problem.

    Right, I understand how that works. When dealing with solar farms though coupling RE systems to grid to increase the power output of utility grid has shown that voltage in RE systems "if" larger than grid potential the voltage will exponentially rise.

    Before a RE system is installed it could be metered at the transformer that voltage could be lower(I.E) 215~220V. More than likely from the load pulled from other neighboring residence. Adding solar to a home off that same transformer fullfills the transformers capacity to achieve and maintain healthier voltage (I.E) 240V~260V. Yes, you are correct initially the inverter samples voltage, along with frequency, there then becomes this resistance to sample what the desired output of the inverter is. If the inverter is fulfilling a demand and reducing load from neighboring consumers, that voltage measured at grid will rise being that of a healthier voltage before an RE system was installed.

    Case in point final sentence of paragraph Quoted from wikipedia: Inverters take DC power and invert it to AC power so it can be fed into the electric utility company grid. The grid tie inverter must synchronize its frequency with that of the grid (e.g. 50 or 60 Hz) using a local oscillator and limit the voltage to no higher than the grid voltage. A high-quality modern GTI has a fixed unity power factor, which means its output voltage and current are perfectly lined up, and its phase angle is within 1 degree of the AC power grid. The inverter has an on-board computer which will sense the current AC grid waveform, and output a voltage to correspond with the grid. However, supplying reactive power to the grid might be necessary to keep the voltage in the local grid inside allowed limitations. Otherwise, in a grid segment with considerable power from renewable sources voltage levels might rise too much at times of high production, i.e. around noon.


    The only area's or nieghborhoods where I have tested and metered low voltage results are typically in over consolidated neighborhood developments most typically condominium and apartment complexes, where the electrical infra structure has been under developed for the over development of population density.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size

    Well, you almost understand it.

    If your purpose here is to cloud discussions and start arguments you're not going to be around very long.
  • SolarPowered
    SolarPowered Solar Expert Posts: 626 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size
    Well, you almost understand it.

    If your purpose here is to cloud discussions and start arguments you're not going to be around very long.

    The intent is not to cloud discussion. I do apologize if that is what you believe the intent is. I do understand that I can be a bit on the abrasive side, and that maybe if I just tone it down a bit the point would come across much more smoothly. I do play devils advocate, maybe not the best personality trait to have in a forum such as this.

    I believe that it just becomes a matter of different strokes for different folks. You understand clearly with your knowledge of book work experience, calculation, and education, while I understand with years of hands on experience. Some where in the middle there is this thing called truth, both from the experience of not only calculated precision which is clear your intelligence exceeds you, where as for me, my education is hands on installing over 8.5 megawatts of power, and dealing with equipment hands on is more my niche. I've realized what is great on paper doesn't always come out the way it should after its built.

    The only issue that perturbs me the most without trying to lose perspective, is that people come to this forum for knowledge and research. Its great, I applaud any one that chooses to learn and be productive. However when I see a thread starter, start a thread asking for specs, saying I am gong to design and build my own system, I have alot to questions that crosses my mind. It took me 6 years installing 8.5 megawatts to even think for a moment that I could start my own designing and building, and I have been a class B contractor for a few years now. In the 6 years of installing solar I've witnessed an electrician getting electrocuted by 550 dc volts @ 30 amps at the combiner, have seen under engineered systems that have failed years later, and any thing in the field that could go wrong did go wrong. Yet I see some individual post that "I've been doing my research on the internet so I'm going to tackle my own designbuild". Things like that sound crazy to me. I have years of experience in solar and its still a learning curve, and I can barely believe that I could comprehend solar to where I can say I am this fantastic expert.

    Now my only argument with you is you say potato, I am saying potatoe, slight difference but I believe we are saying the same thing. You say hey an inverter is to produce 215 thats why its called a 215. I say hey I agree, however the spec says it makes more. Thats all it is to sum it up. Yoru a good guy caribicoot, and you have a lot of patience to deal with people in this forum and be willing to sacrifice that time and energy. I commend you for doing an awesome job. I do apologize to this forum and you for being a very dry and abrasive individual.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Planning my own PV install, need confirmation on wire/breaker size

    I have experience as well. Quite an awful lot of it, in fact. And I do mean "awful" in some instances as I'm always cleaning up "messes" made by people who didn't know what they are doing.

    We try to nip that in the bud around here. :D