Is it time for new surge suppression devices?


Several things have changed over the past 20 years, including lower clamping voltages and the NEC now recommends whole house surge suppression.  I've written about it in my latest posting here:

https://inatinear.blogspot.com/2021/09/time-for-new-surge-suppression.html
erik_squires
NEC now recommends whole house surge suppression
Erik, I think you meant to say NEC now requires


Your State, county, or city, may not have adopted the 2020 NEC as yet. Check your State.
https://www.jadelearning.com/nec-code-adoptions-by-state/

For new residential construction.
2020 NEC:

N 230.67 Surge Protection.

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

N (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.

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

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

N = New for 2020 NEC.
Note (D) Replacement.

"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."

The exception allows the SPD to be installed at the first Sub Panel (s) after the service equipment main disconnect(s), main breaker(s).

Never buy an SPD that is not UL Listed 1449-3rd Edition.

Why type 2 SPD must be mounted as close as possible to the electrical panel bus.
https://www.youtube.com/watch?v=rVz3uy50Egw

https://www.youtube.com/watch?v=YZDKRFgTkow

.
Thanks for the reading. You are correct but I can no longer edit the OP.

Yes in my blog I state it as required. It is (of course) true that your locality may not require a surge protection device if it uses an older version of the NEC or has amended it to exclude it (which is legally possible but I know of no such exclusion). 


@erik_squires  
The element most often used is Metal Oxide Varistor.  Siemens uses multiple large 150VAC 40mm MOVs.  Here is data sheet for large MOVs: https://www.mouser.com/datasheet/2/240/Littelfuse_Varistor_HA_Datasheet_pdf-596397.pdf
The problem with MOVs is, that their clamping voltage is temperature dependent - lower at high temp.  Because of that 150VAC MOV at 25degC will start conducting (1mA) at as high as 264V (187VAC).  At 200A clamping current it is 405V (287VAC), but with multiple parallel MOVs current will divide - lowering clamping voltage of each MOV (stronger protection is better).    150VAC is just rating at 85degC (including element tolerance) to make sure they stay off in normal conditions.  IMO whole house protection is necessary, since today everything contains electronics.    I use surge suppressing breaker (Siemens panel), that replaced double 20A breaker.  My gear is plugged into Furman Elite 20PFi conditioner with tight non-sacrificial over/under voltage protection.  I still unplug during thunderstorms or when I travel.  I'm moving to Florida now and plan to install protection as big as I can find - perhaps Siemens FS140 or even couple of them.  Still, I would highly recommend even basic protection, like mentioned breaker:  https://www.amazon.com/dp/B0052MG5K0/?coliid=I2G7DXSO9P4HAH&colid=41JEAXYNOO5S&psc=1&ref...
That's pretty much the same setup I use @kijanki except I gave up my 2 breaker slots.  I have about 8 open so this wasn't a big sacrifice.

The clamping voltage is a complicated thing so I go by what the manufacturers rate their gear at.
Eric, Yes, clamping voltage is complicated.  I'm only sure they have to specify lower voltage because of MOVs breakdown voltage tolerance.

Thank you for bringing this subject - perhaps now whole house protection will be viewed as something standard/required.
Thank you for bringing this subject - perhaps now whole house protection will be viewed as something standard/required.

As @jea48 corrected me it is required now, though a retrofit is not mandatory for older homes I do hope most people who can afford to do so will make these upgrades. In addition to the life safety issues with which the NEC is primarily concerned with, I have so many home automation or accessories that I cannot surge protect that the surge protector is a small part of the overall investment. 

This includes more delicate things like my fire alarms and automated light switches in addition to what may be my most precious appliances right now, my air conditioning units. :)
Wife = splurge suppression device.
Oh, surge suppression. 
;)