Page 2 of 2 FirstFirst 12
Results 11 to 15 of 15

Thread: 2016 CEC Interpretation - Heads Up

  1. #11
    Join Date
    Feb 2009
    Location
    Austin, TX
    Posts
    629
    That definition also appears in NEC 2017. Additionally, 690.4(D) states:

    (D) Multiple PV Systems. Multiple PV systems shall be permitted to be installed in or on a single building or structure. Where the PV systems are remotely located from each other, a directory in accordance with 705.10 shall be provided at each PV system disconnecting means.

  2. #12
    Join Date
    May 2011
    Posts
    3,695
    Quote Originally Posted by SolarPro View Post
    That definition also appears in NEC 2017. Additionally, 690.4(D) states:
    Yes, unfortunately the 2016 CEC is the 2014 NEC, which reads 'Multiple Inverters' instead of 'Multiple PV systems'. Glad that section got fixed in the 2017 code though.

  3. #13
    Join Date
    Feb 2009
    Location
    Austin, TX
    Posts
    629
    Most AHJs will probably consider the 2017 change when deciding how to interpret the 2014 edition. It doesn't make a lot sense to enforce to enforce an interpretation that is diametrically opposed to the most recent Code revision.

    The 2017 Code also describes the identification and directory requirements where a building has multiple PV systems that meet different rapid shutdown requirements. You just need to clearly identify the subarrays that have NEC 2017 vs NEC 2014 vs nor rapid shutdown. You don't have to retroactively upgrade the existing systems.

  4. #14
    Join Date
    May 2013
    Location
    Massachusetts
    Posts
    2,215
    Quote Originally Posted by jaggedben View Post
    I have always felt that, under this definition, one inverter generally qualifies as one system. Turn it off or remove that system, and generally any others present are still suitable for connection to a utilization load. There are some situations that clearly ought to be treated differently: for example, microinverters on the same circuit sharing an overcurrent device and disconnecting means. Or systems where single-phase inverters are stacked to create split-phase or wye systems (some off-grid systems). I have felt for a while that various code sections should be revised accordingly to not suggest that multiple inverters are required to be combined before connection to distribution.
    I think if the inverters are electrically combined before interconnecting to general loads, and have a master shutoff for the group of inverters, that they collectively would qualify as "1 system".

  5. #15
    Join Date
    May 2011
    Posts
    3,695
    Quote Originally Posted by Carultch View Post
    I think if the inverters are electrically combined before interconnecting to general loads, and have a master shutoff for the group of inverters, that they collectively would qualify as "1 system".
    While I can see the sense in thinking that, I don't think that the code definition entails it. And I'm not sure I see a safety issue that would justify amending the code to make the definition more strict.

    Moreover, it doesn't cover all cases sensibly. Say I sell new microinverter systems to two different homeowners, both of whom happen to have previously existing string inverter systems. Homeowner A has space in his service panel for both 2-pole breakers, so I install the new one there and call it a day. Homeowner B has no breaker spaces left, so I install a small 'combiner' sub and move the existing inverter output into it to make everything work. Does it really make sense to call B 'one system' and A 'two systems'?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •