Has anyone here had experience using the QO brand plug in type secondary surge protector? The specific product I'm looking at is the QO 217SB. The current panel arrangement at the job in question is a 200A main breaker feed through panel located outdoors. Coming off the feed through lugs is a 200A indoor panel located inside the residence. There is also a 100A 2 pole subfeed from the bus of the exterior panel feeding a sub panel at the opposite end of the dwelling.If the surge protector device was installed in the exterior panel, would it protect everything "downstream"? Another question. Why is the product described as "secondary" proteprotection? Is there such a thing as "primary" protection? If so, what would be required to achieve the that protection? Thanks much for any help
plug in style secondary surge protector
- Thread starter nizak
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- Placerville, CA, USA
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There are classes of SPDs. Some are allowed to be connected to service conductors without intervening OCPD, while others require external OCPD. That may be the distinction being made in the product description.
kwired
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Does it protect everything downstream? Yes, and No. This protector is nothing more then a parallel device to the circuit it is connected to. A transient voltage is introduced (usually from supply side but could be introduced anywhere in the circuit) and this device is designed to clamp voltages over a certain level. The main kind of voltage it is intended to mitigate is those of short duration - maybe just a few cycles, but could successfully clamp for several seconds if the joule rating of the device isn't exceeded. That transient is still present elsewhere in the circuit but most of the time is diverted before it has a chance of doing harmful damage to "protected" components.
Many of these "whole house" protectors still recommend you use local protectors at critical equipment, and generally if they have any equipment protection warranties will not honor that warranty if there wasn't local protector at such equipment as well.
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