Arrester/TVSS ratings listing

[cessna]

I am looking for the simple schematic difference between an Arrester rated and TVSS rated MOV constructed SPD device. Some are rated for both and some are rated only for TVSS applications. We have an installation where are required to install a $120 device right in parallel with a $2500 in panel device because of the explosive requirement in 280 for arrester rating.
What is the difference or is it just a listing??

 

[bphgravity]

Re: Arrester/TVSS ratings listing

Surge arrestors and TVSS's operate in almost identical ways. They both shunt the high voltage surges to ground. The main difference is that arrestors are rated and designed for line side connection and are generally for lightning protection whereas TVSS's are listed and designed to be connected to the load side of the service equipment and are not generally effective for ligtning.

 

[dereckbc]

Re: Arrester/TVSS ratings listing

Surge arrestor meaning has been lost over the years. You can by a surge arrestor for telephone lines, I/O ports, control lines, etc. They use the same components as a TVSS such as Selenium, SAD,s, Gas Tubes, and MOV's.

Lightning arrestors are still used in the electrical industry primarily along transmission lines and upstream of a facility service entrance. Low voltage systems (600 and less) now have TVSS at the service entrance and branch panels in place of arrestors. TVSS offer the following advantages over an arrestor:

* Lower or tighter let through voltages, or better performance.
* Longer life.
* Improved safety, less destructive debris is damaged.
* Full monitoring capability.
* Internal fusing
* Filtering capability to remove low level noise/surge.