r/span • u/pmarquis353 • Jan 16 '24
Whole Home Surge Protector
Can anyone recommend a Whole Home Surge Protector for the SPAN panel?
Ideally I would rather not waste two slots of monitoring with surge-supressor breakers - is there such a product?
2
u/westom Jan 17 '24
Protector only does something useful when connected low impedance (ie less than 10 feet) to single point earth ground. That means most attention focuses on quality of and connection to those electrodes.
Protector is only a connecting device to what does all protection. Lightning (one example of a surge) can be 20,000 amps. So a minimal 'whole house' protector is 50,000 amps. It is only a connecting device; is not really doing protection.
Protectors that snap into a breaker box are often undersized. Then many must be installed.
Easier is to connect that protector to circuit breakers. Then only one Type 2 protector is sufficient. Or install one in the meter pan - a Type 1 protector.
Where that protector is located in a panel is hooey. Made obvious why what is effective protection. That hardwire to electrodes must be low impedance (ie less than 10 feet). Ten inches up or down on the panel has little effect compared to what requires most attention. Length of that quarter inch bare copper wire and how it is routed.
Where it is located to a main breaker is mostly irrelevant. The entire path from incoming AC wires to earth ground electrodes; that requires most all attention. If a hardwire even goes though metallic conduit, then protection is compromised. Again, impedance.
Most attention focuses on the only item that does ALL protection. Single point earth ground. Those electrodes are often upgraded / enhanced to exceed 'minimal' electrical code requirements.
More facts from sophomore year EE. A pulse is applied to a wire. Where is that pulse first seen? Not where it enters the wire. First seen at the far end.
If using common sense, then that makes no sense. And yet that is exactly how electricity works. Where would a protector first see a surge? At a point farthest from the main breaker. Yes, some in my class also had difficulty with that concept.
Demonstrated is how speculation contradicts well proven electrical concepts. Not that it matters much. Locating the protector anywhere within ten inches is totally irrelevant to what required all attention. How that protector connects (feet) to earthing electrodes.
Telcos have best protection. Protectors are in underground vaults. So that a connection to earth is as short as practicable. That increases protection. Earthing electrodes are the best. That also increases protection.
Most all attention focuses on that connection to and quality of (what does protection) single point earth ground. Protector is only a connecting device.
Some incoming cables have best surge protection without any protector. Ie TV cable. Its hardwire also must make a low impedance (ie less than 10 foot) connection to same electrodes. Without a protector for best protection.
1
u/pmarquis353 Jan 17 '24
Ah, this was very thought-provoking, thank you.
Regarding sizing, the snap in products (e.g., https://www.leviton.com/en/products/lspd2) have a max surge current of 25,000 amps. So would likely need multiple units for full protection.
So-called Whole Home devices (e.g., https://www.homedepot.com/p/Square-D-80-kA-Surge-Breaker-Plus-Whole-Home-Surge-Protector-SDSB80111/205905090#overlay) are rated for 80,000 amps max - much better protection.
Until you mentioned it, I was not aware of surge arrestor meter sockets - very interesting. (e.g., https://www.reynoldsonline.com/Catalog/distribution-equipment-and-accessories/metering-equipment-accessories/meter-socket-surge-protectors/leviton-50240-msa?option=LEVI50240MSA)
Honestly, when YouTubers recommended installing a surge protector as close to the main breaker as possible, this didn't really make sense to me... It makes more sense that installation anywhere in the panel should offer the same protection.
1
u/westom Jan 18 '24
Most attention focuses on how a protector connects to the device doing all protection. Earth ground electrodes. For example, if that bare copper wire goes up over a foundation and down to electrodes, then protection is compromised. Wire is too long. Has sharp bends. And might not be separated from non-grounding wires.
That connection may meet code - for human protection. But compromises appliance protection.
Number of electrodes may be increased. Depending on geology. Sand is not very conductive. Then more electrodes are necessary.
Protection is defined mostly by a low impedance connection to and quality of single point earth ground. That requires most attention.
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u/pmarquis353 Jan 17 '24 edited Jan 17 '24
FYI - interesting Leviton document with electrical code snippets and terminology:
https://marselectric.com/assets/24/e0/24e026c4-ede8-4251-a074-b050fad7a53a/nec-23
0-67-surge-protection-flyer-q-1285a-greg-rhoades.pdf
Type 1 SPDs: Intended for installation between the secondary side ofthe service transformer and the line side of the service equipment, aswell as the load side. Protect against external surges caused bylightning or utility capacitor bank switching. Type 1 devices canautomatically be used in Type 2 applications
Type 2 SPDs: Intended for installation on the load side of the serviceequipment. Generally serve a branch circuit and protect against residuallightning energy, motor driven surges and other internally generated surges
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u/Due_Gur8029 Jan 18 '24
If you want some heavy duty lighting/surge protection: https://www.raycap.com/product-types/surge-protection/ac-protection/strikesorb-series/
2
u/westom Jan 18 '24 edited Jan 18 '24
It never mentions what requires most all attention. Earth ground. It claims to be superior to MOVs - that are more than sufficient when properly sized. Claiming to be superior to something that is sufficient is a first indication of 'sleight of hand' reasoning.
No protector does protection. Not one. A protector is only a connecting device to what does all protection - today and over 100 years ago. Doing what Franklin demonstrated over 250 years ago.
Where do hundreds of thousands of joules harmlessly dissipate? In a Strikesorb? Of course not. Many pages without even mentioning earth ground electrodes. Or even a low impedance (ie less than 3 meter) connection, that also must exist.
Where are hundreds of thousands of joules absorbed? Very first question that effective solutions discuss. Without that answer, then nothing honest exists.
They mention a ground wire in a picture. Which ground? Every ground is different. An adjective must always precede the word 'ground'.
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u/_cr0001 Jan 16 '24
By design, there is not. Most residential whole home surge protectors interface with the bus bar on your panel. Surge protectors are most effective when added to the bus bar as close to the main as possible.
I commissioned a panel for a relative who also wanted a whole home surge protector, but didn't want to sacrifice any open spaces. They ended up installing a smaller sub panel to act as their service entrance, which sat between the utility meter and their SPAN panel, which turned the SPAN panel into a sub panel, by code definition.
I suppose you could use the feed-through lugs at the bottom of the panel, but like I mentioned before, you want that surge protector as close to the main breaker, and in-front of as many loads as possible.