Announcement

Collapse
No announcement yet.

Electrical Code and PV, grey areas

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Electrical Code and PV, grey areas

    So, I have been going through the Canadian Electrical Code 2015 and have identified several grey areas that we have not been penalized for to date by field inspectors. I wanted to see what this community thinks of these grey areas, and how they deal with them in their installations.

    ​64-060(2) Disconnecting means (Renewable energy system section)

    The disconnecting means referred to in Subrule (1) shall be in accordance with Rule 84-024 and shall be
    a) located within sight of and within 9 m of the equipment; or
    b) integral to the equipment
    • Does this mean that the AC disconnect for a PV system needs to be within sight of the equipment? How is that possible, if the panels are on the roof and the AC disconnect is on the wall of the house?
    84-024 (1) Disconnecting means - General (Interconnection of Electric Power Production Sources section)

    Disconnecting means shall
    a) be capable of being energized from both sides;
    b) plainly indicate whether it is in the open or closed position;
    c) have contact operation verifiable by direct visible means if required by the supply authority;
    • Typically we use a breaker box as our disconnecting means. Does this mean that the breaker box needs to have a clear cover?
    64-200(1) Marking (Solar photovoltaic systems section of Renewable energy systems section)

    In addition to the marking requirements given in Rule 64-072, a permanent marking shall be provided at an accessible location at the disconnecting means for the photovoltaic output circuit, specifying the following:
    a) the rated operating current and voltage;
    b) the maximum photovoltaic source circuit voltage calculated in accordance with Rules 64-202(1) and (2); and
    c) the rated short-circuit current.
    • Does this mean that we have to create a lamacoid stamp (white lettering on red background) that indicates the open circuit voltage and short circuit current of each individual string feeding a string inverter?
    • What about for microinverters? Do we need to put the inidvidual panel short circuit current and open circuit voltage on the AC disconnect plaque?
    64-210(5) Wiring method (Solar photovoltaic systems section of Renewable energy systems section)

    Where the dc arc-fault protection referred to in Rule 64-216 is not located at the module, photovoltaic source circuit conductors and cables installed on or above a building, and installed in accordance with Subrules (1), (2), and (3) shall be provided with mechanical protection, in the form of and enclosed raceway or other acceptable material to protect against damage from rodents.
    • Does this mean that we need to wrap the RPVU wiring that runs from the module to the microinverter located directly underneath it with some form of "acceptable material" that will protect it against damage from rodents?
    64-210(6) & 64-210(7)

    (6) Notwithstanding Rule 12-2202(1), (2), and (3), Type RPVU conductors shall be permitted to be installed in cable tray for the interconnection of the solar photovoltaic system
    (7) Type RPV conductors installed in a raceway shall be permitted for the interconnection of the solar photovoltaic system.
    • Does this mean that RPV and RPVU cables are the ONLY cables that can be used to transmit DC current to a string inverter? What about TECK 90 cables?
    64-214(1) Overcurrent protection for apparatus and conductors (Solar photovoltaic systems section of Renewable energy systems section)

    Notwithstanding Rules 64-058(1) and 64-066(1)(a), individual overcurrent protection devices shall not be required where the sum of the available short-circuit current from all photovoltaic source circuits connected to the same power conditioning unit is not greater that the rated ampacity of the apparatus or conductors.
    • Does this mean that overcurrent protection devices are not needed on PV source circuits (DC) if all the source circuit conductors are large enough to handle the current from the entire array? In other words, if each PV string has wires big enough to accommodate the current from all the other strings combined, then you don't require overcurrent protection devices on any of the strings?
    Last edited by macdonaldtomw; 05-17-2016, 11:49 AM.

  • #2
    All good questions to ask someone that is local to your area and very familiar with the latest codes. That may even have to be the person or adjacency that inspects and approves the installation.

    Comment


    • #3
      Indeed, that is what my thought was too. Unfortunately our electric utility company is a private monopoly that has a legislated profit margin (i.e. by definition they can't lose money). As a result, their electrical inspections department is a joke, and most of the inspectors aren't knowledgeable about the requirements around PV. That's part of the reason I would like someone other than the utility to tell me what is and isn't allowed under code so that I can be a bit more confident when I'm fighting with them.

      Comment


      • #4
        Unfortunately anyone here that gives you an answer to your questions has now opened themselves to a liability if you or someone else gets hurt by following their suggestions.

        Besides. The best knowledge of what has to be installed will come from someone that does it for a living and has had their installations pass inspection.

        If you choose to perform an DIY install without getting either approval or following what your electrical inspectors want you could be setting yourself up for a legal problem.

        I am not trying to keep you from performing the work. Just trying to let you know that when it comes to the Electric Code the local inspector is "always right" even when they are wrong. While not always fair that is the way it is for most of the US.
        Last edited by SunEagle; 05-17-2016, 03:30 PM. Reason: spelling

        Comment


        • #5
          Originally posted by macdonaldtomw View Post
          Indeed, that is what my thought was too. Unfortunately our electric utility company is a private monopoly that has a legislated profit margin (i.e. by definition they can't lose money). As a result, their electrical inspections department is a joke, and most of the inspectors aren't knowledgeable about the requirements around PV. That's part of the reason I would like someone other than the utility to tell me what is and isn't allowed under code so that I can be a bit more confident when I'm fighting with them.

          These are NOT questions for your UTILITY company. These don't have anything to do with the utility. These are all code issues.
          You should be ask of your AJH (county/city permit office and inspectors)
          OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

          Comment


          • #6
            The best knowledge of what has to be installed will come from someone that does it for a living and has had their installations pass inspection
            I install and design solar PV systems for a living, and have yet to have an installation fail an electrical inspection. I'm just trying to figure out how to navigate these grey areas in light of the sweeping changes to the electrical code with respect to PV. I'd like to find out from other professional solar installation companies what they have been doing to address these issues.

            I think part of the problem with the Electrical codes and its enforcement is that no one wants to provide an opinion or interpretation on what the code means until the inspector shows up and tells you that you've failed. It is very frustrating to have to just cross your fingers instead of being able to be sure when you design a system that it is code compliant.

            As I mentioned before, with a regulatory system such as we have here the utility can pretty much do whatever they'd like. In the case of PV installations, the utility fights tooth and nail to make it as difficult as possible for companies like mine to install PV, because at the end of the day it means that their iron fist grip on the monopoly on power production weakens an iota for every panel that someone installs. Part of how they do this is take a hard line interpretations of the code, so I guess part of what I am hoping to find out from this forum is what interpretations everyone here has on the issues I list and see what tact they take when arguing with the electrical inspector. Another part of what I'd like to find out is which portions of the code issues I list that most installers simply ignore in order to bring the cost of the project down. It is very hard to turn a profit installing PV where my company is based so any suggestions on code points that aren't enforced in real life would be greatly appreciated.

            Comment


            • #7
              I understand your frustration. While I do not install PV systems I have over 40 years experience in the electrical power field. Getting anyone to be specific on a line of code is hard when it falls into what you suggest as a "grey area". Everyone seems to interpret what is stated in their own way which can add a significant cost to the installation to make one person happy.

              Even the NEC 2014 has not been accepted by all of the US locations yet. It becomes hard to know what the latest code for any area that needs to be followed let alone what it means.

              Comment


              • #8
                Originally posted by macdonaldtomw View Post
                So, I have been going through the Canadian Electrical Code 2015 and have identified several grey areas that we have not been penalized for to date by field inspectors. I wanted to see what this community thinks of these grey areas, and how they deal with them in their installations.

                ​64-060(2) Disconnecting means (Renewable energy system section)
                none of this seems grey, but here is some very vague info. In all cases local AHJ is right (or there is no other way )

                Originally posted by macdonaldtomw View Post
                [*]Does this mean that the AC disconnect for a PV system needs to be within sight of the equipment? How is that possible, if the panels are on the roof and the AC disconnect is on the wall of the house?
                84-024 (1) Disconnecting means - General (Interconnection of Electric Power Production Sources section)
                within sight of the inverter usually (AC equipment)

                Originally posted by macdonaldtomw View Post
                [*]Typically we use a breaker box as our disconnecting means. Does this mean that the breaker box needs to have a clear cover?
                64-200(1) Marking (Solar photovoltaic systems section of Renewable energy systems section)
                You likely should have a locking disconnect or use a disconnect box.


                Originally posted by macdonaldtomw View Post
                [*]Does this mean that we have to create a lamacoid stamp (white lettering on red background) that indicates the open circuit voltage and short circuit current of each individual string feeding a string inverter?[*]What about for microinverters? Do we need to put the inidvidual panel short circuit current and open circuit voltage on the AC disconnect plaque?
                64-210(5) Wiring method (Solar photovoltaic systems section of Renewable energy systems section)
                you should have a placard with this information permanently marked on it.

                Originally posted by macdonaldtomw View Post
                [*]Does this mean that we need to wrap the RPVU wiring that runs from the module to the microinverter located directly underneath it with some form of "acceptable material" that will protect it against damage from rodents?
                64-210(6) & 64-210(7)
                Is the module putting out over 50V?


                Originally posted by macdonaldtomw View Post
                [*]Does this mean that overcurrent protection devices are not needed on PV source circuits (DC) if all the source circuit conductors are large enough to handle the current from the entire array? In other words, if each PV string has wires big enough to accommodate the current from all the other strings combined, then you don't require overcurrent protection devices on any of the strings?
                generally you can combine 2 strings without need of fuses. SolarEdge has possitioned that you can combine 3 or more due to the fact that the optimizer is a rate limiting device.
                OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

                Comment


                • #9
                  Thanks for the response!

                  within sight of the inverter usually (AC equipment)
                  So, in the case of micro-inverters located under each PV module, this rule is impossible to be in compliance with.

                  you should have a placard with this information permanently marked on it.
                  I guess we will have to make a custom placard for each individual job we do that has that job's specific specifications printed on it.


                  You likely should have a locking disconnect or use a disconnect box.
                  Here is what we typically use for AC disconnect:


                  You can lock the box shut while the breaker is in the off position, however once the box is closed there is no indication of whether the breaker is in the off position or not. That's why I was thinking perhaps we would need a disconnect with an external actuator handle or perhaps just a clear cover (so that you can see what position the breakers are in).

                  Is the module putting out over 50V?
                  No, its not. Good point! Actually, if you look at 64-216 it has an 80 V limit in the CEC.

                  Comment


                  • #10
                    Originally posted by macdonaldtomw View Post
                    So, in the case of micro-inverters located under each PV module, this rule is impossible to be in compliance with.

                    I guess we will have to make a custom placard for each individual job we do that has that job's specific specifications printed on it.
                    For micros the disconnect is generally placed by the meter or if the MSP is outside, by it (though when MSP is outside it is usually in close proximity to the meter).

                    And yes you need a placard for each individual system. Others are doing this, and you claim

                    Originally posted by macdonaldtomw View Post
                    I install and design solar PV systems for a living, and have yet to have an installation fail an electrical inspection.
                    If placards are required, how have you managed so far?
                    OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

                    Comment


                    • #11
                      We have been installing placards that indicate that the disconnect is energized from both sides, but instead of having a custom placard made for each individual job that indicates that job's specific amperage etc we just have a stack of placards indicating that the disconnect is energized from both sides that we bring to each job and affix to the cover of the disconnect.

                      I guess our inspectors don't care about the voltage and amperage portion of the requirements for information on the placards (yet).

                      So, for microinverters it is impossible to be in compliance with the code as it is currently written. I guess they will have to amend the PV section in the next electrical code update to allow for the disconnect not being installed in a location where you can see the PV array.

                      Comment

                      Working...
                      X