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  1. #1
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    Default 2020 NEC Surge Protection

    Oh good grief. California just started enforcing the 2020 NEC (2022 CEC) at the beginning of 2023 and I have just begun looking into the changes. Is this another solution looking for a problem? Is this another device pushed-through by the manufacturer(s) looking to get consumers to pay for their beta-test?

    From the 2020 NEC

    230.67 Surge Protection.

    (A) Surge-Protective Device. All services supplying dwelling units shall be provided with a surge-protective device (SPD).

    (B) Location. The SPD shall be an integral part of the service equipment or shall be located immediately adjacent thereto.

    Exception: The SPD shall not be required to be located in the service equipment as required in (B) if located at each next level distribution equipment downstream toward the load.

    (C) Type. The SPD shall be a Type 1 or Type 2 SPD.

    (D) Replacement. Where service equipment is replaced, all of the requirements of this section shall apply.

    From the standpoint of a home inspector and our "Standard of Care" (I know, moving target)...


    1. Is this a safety issue and is this something that we should start recommending as an upgrade like we do with GFCIs, bonding of metal piping, additional grounding electrodes, etc?
    2. Is this going to provide surge protection for individual electronic appliances within the home or is this specifically for the electrical system and we still need surge protection for sensitive electronics? I cannot tell from my quick perusal of Eaton's site, but Square D does imply individual electronics.
    3. If SPD is for the system only (kind of indicated in the code wording), and one is present, do we notify our clients that they should still have surge protection for individual appliances?
    4. How many surges can one of these devices absorb? Are they sacrificial (like a fuse) or resettable (like a circuit breaker)?
    5. If a home experiences a surge, should the system be evaluated by an electrical contractor? How would someone know that a surge has occurred?
    6. If sacrificial, is there a way to know that the device is no longer functional and needs replacement? It looks like both Eaton's and Square D's have LEDs, so some kind of indicator is apparently present.


    It looks like a "Type 1 SPD" is installed before the main disconnect and a "Type 2 SPD" is installed after the main disconnect. I interpret this (in part) as the "Type 1" being more hazardous/difficult to replace than a "Type 2".
    SPD Definition Link

    Eaton's claim on their "Type 1 SPD" is:
    "Provide superior protection for sensitive electronics with low Voltage Protection Rating values."
    Eaton SPD Link

    Which means..?

    Square D does state:
    "Whole house protection including appliances, HVAC, lighting, cable, ethernet, and telephone"
    Square D SPD Link


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    Last edited by Gunnar Alquist; 01-22-2023 at 05:49 PM.
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  2. #2
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    Default Re: 2020 NEC Surge Protection

    Either is supposed to protect everything down stream of it.

    https://www.electrical-installation....%20the%20loads.

    On older builings (existing before that code was adopted), nothing to look for ... unless the service equipment was replaced after that code was adopted.

    New construction and service equipment replacements after the effective date will like have it built in. If not ... David can address it better than I can as he is more involved and up to date on things.

    Being as manufacturers knew it was coming in prior to adoption of the 2020 NEC (they basically have 3 years notice during code change and comment period), and thus is now 3 years later, most electrical supply houses probably have conforming service equipment in stock.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  3. #3
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    Default Re: 2020 NEC Surge Protection

    Quote Originally Posted by Jerry Peck View Post
    ... most electrical supply houses probably have conforming service equipment in stock.
    I' have no doubt that the local suppliers will have them. I am concerned that they will be problematic. AFCI devices have gone through changes over the years. The first generations were running warm, which the manufacturers said was normal, but later said "hey, we fixed the hot breaker problem!" Contractors and homeowners were the beta test.

    I know electrical contractors who are still dealing with problematic AFCIs (in new construction) that they swear are tripping because of the device rather than an actual arc-fault. They will switch-out an AFCI breaker that is tripping repeatedly with another in the same panel and both circuits will work fine.

    I recognize that there is a possiblity that a good AFCI breaker located on a bad circuit is switched-out for a bad AFCI that happens to be on a good circuit. But, if that is the case, then there are AFCI devices that are not tripping when they should.

    It just seems like manufacturers create devices that aren't a real problem, then pressure to change the codes to make the newly created devices a requirement.

    grumble grumble grumble


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  4. #4
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    Default Re: 2020 NEC Surge Protection

    Quote Originally Posted by Gunnar Alquist View Post
    I' have no doubt that the local suppliers will have them. I am concerned that they will be problematic.
    Likely so.

    But the problems will most likely be the devices not working and the homeowner not knowing that the devices are not working (or even knowing that such SPD are even installed).

    Unlike GFCIs and AFCIs, SPDs don't trip power off. They just 'catch' the surge spikes and take those surge spikes to ground. David, is that a good 'basic description' of SPDs?

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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  5. #5
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    Default Re: 2020 NEC Surge Protection

    You've got it right, Jerry.

    FWIW, I've never heard of SPDs/TransientVoltageSurgeSuppressors/Overvoltage Devices going wonky and causing grief. So if a new 1-2 family panel or new building or new service is missing its TVSS, I'd flag it, just as I recommend flagging a building lacking a firefighter disconnect per 230.85

    I have seen, and in fact, created a violation with a Type 2 SPD. Some of them expected or maybe still expect you to stick its leads in with the service cable into the same lugs, which are not listed for the use.

    A bit more to say, in response to another of Gunnar's concerns, somewhat conflicting with what you could read into Jerry's response. These protect everything in the system from having the great honking surge hit (up to their rating, which certainly doesn't include direct lightning strikes). But how well? How much of a transient swells in the system as it enters and then as they are diverting it to ground? This is why some people add Type 3 TVSS well downstream, to protect sensitive equipment. Even further, people with, say, studio-quality audio don't rely on MOVs diverting surges to ground, which means dividing the surge between the MOV path and the downstream wiring. They buy quite-expensive circuit-specific L-C protection, to choke off downstream surges.

    As for your other question, to my mind there was hanky-panky in the way the rule was added. The substantiation cited commercial data, but those properties were left out. These data were extrapolated to 1-2 family residences, which resulted in less blowback. Kinda valid anyway, but .. . .

    I sent email today to a colleague who spent decades on lightning protection evaluation. My question was how important it would be to add Type 3 TVSS to protect appliances with expensive circuit boards. My sweetheart was kind of concerned, given the difficulty we've had getting our fridge's C&C fixed. Myself, I am a tiny bit concerned about protecting my computer. The David office is upstairs, and this computer has a lot on it that I count on; whereas the wifely office is downstairs, and she uses a laptop owner by her employer.


  6. #6
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    Default Re: 2020 NEC Surge Protection

    Quote Originally Posted by david shapiro View Post
    I sent email today to a colleague who spent decades on lightning protection evaluation. My question was how important it would be to add Type 3 TVSS to protect appliances with expensive circuit boards.
    I always connected my computers, including my notebook computers, to APC 1500 VA rateUPS units.

    And I would plug the UPS unit into a surge protected plug strip, with another surge protected plug strip plugged into the UPS unit as they never had enough surge/battery back up receptacle outlets for what I was plugging in, and the surge protected only receptacle outlets didn't provide the battery back up I wanted to have (I didn't need hours and hours of backup as I would shut everything down within a few minutes of a power failure ... but I did want those few minutes to be able to save and shut things down.

    David, did the surge protection of decent quality surge protected plug strips and of the APC UPS units actually offer much surge protection? Or was it just more of a "feel good" effort on my part?

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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  7. #7
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    Default Re: 2020 NEC Surge Protection

    Yes, if their values exceeded those of joules (the joules to which they were subjected). What was their rating? Did they offer "burned out" indicators? Those would be the technical ways to answer your question.

    As i understand it, the concept of cascading protection is based on the wiring between the point where the impulse entered your wiring system and the point of use having the effect of further smoothing out the wave.

    I'll let y'all hear what Heinz responds to my questions, but you need to recognize that they're based on the fact that where I live is not considered a high-lightning area.


  8. #8
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    Default Re: 2020 NEC Surge Protection

    Quote Originally Posted by david shapiro View Post
    Yes, if their values exceeded those of joules (the joules to which they were subjected). What was their rating? Did they offer "burned out" indicators? Those would be the technical ways to answer your question.
    Maybe , don't remember, and yes.

    My thinking was to use enough protective devices of decent quality as 'inclined fuses', so to speak, so as to suffer limited replacement cost for "disposable" items to protect what I was wanting to protect: my computers and backup network drives.

    In Florida, where we were (South Florida then Ormond Beach/Daytona Beach), while wr were not in the 'Lightning Capital of Florida' area, Florida was/is the Lightning Capital of the US", so we had more than or share of nature's fireworks on a regular basis.

    Here in Asheville, NC (a 25-minute/14 mile drive to downtown Asheville from where we live) we haven't had anywhere near the Lightning show as we did in Florida.

    No earthquakes, no blizzards, no hurricanes, no alligators ...

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  9. #9
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    Default Re: 2020 NEC Surge Protection

    Oddly I just saw one of these installed a few weeks ago. I wondered what the hell is this thing doing here. It wasn't a new construction house. I'm assuming the Seller put it in for his wood working tools.
    Anyway I wrote it up for 2 reasons and moved on.
    - wired to main lug with 100A disconnect breaker
    - manufacturer spec I looked up specifically stated it needed to be wired to a 50A max. breaker
    It was an Eaton Type 2

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  10. #10
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    Default Re: 2020 NEC Surge Protection

    Quite right you were, Markus.

    I can see why the installer might have done that. "The curse of knowledge" usually refers to the fact that I am likely to assume that basic information I know is equally available to my audience. (Teachers and home inspectors know this is often not true.) There's another curse of knowledge: knowing how things should work, because I've dealt with/installed them a zillion times before. (I talk about this in Safer home repair; no, I haven't found a publisher yet.)

    It used to be that the instructions for TVSS devices said to connect them directly to the service conductors. Yes, the lugs they enter are not listed for multiple conductors. Realistically, though, adding a skinny TVSS lead is not going to interfere with contact between SE conductor and lug. Equally important, the more we shorten (and to some degree, straighten) those leads the better they divert overvoltage to ground.

    All it takes for the expert, the old-timer, for the engineer or physicist who thinks this stuff through, is to not bother reading the instructions.

    Violation.


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