Gary wrote:
My bad. Here you go...

http://www2.sea.siemens.com/Products...guagecode= en

IMHO Siemens does not have particular good information on these
products. They are evaluated under different UL standards which makes
the specs difficult to compare. In particular, 175V is not comparable to
500V. Siemens gives no guidance on when you would use one over the other.

I would choose the QSA2020TVSS. It is a TVSS (transient voltage surge
suppressor). Most suppressors are TVSSs. [The term "TVSS" is being
replaced by "SPD" - surge protective device].

The QSA2020 is a "secondary surge arrester".

The warrantee on the QSA2020TVSS includes devices not included in for
the QSA2020.
(The text says "Hard wired appliances, including refrigerators,
freezers, ... washers, ... dryers, ...." none of which are normally hard
wired - probably a mistake.)


For comparing suppressors w correctly says that the energy (Joule)
rating indicates the life of the device. While that is quite true, both
guides warn that there is no standard for measuring the Joule rating,
and unless the same test method is used the specs are not comparable.
Because some manufacturers fudge the specs, some other very good
manufacturers, unfortunately, no longer provide Joule ratings.

=============================================
The Siemens site includes:
"combined use of quality protectors at the building entrance, and
appropriate plug-in protectors at the point of use can virtually
eliminate all damage from lightning and surges."

Yet another source that disputes poor w's crackpot ideas about plug-in
suppressors.

--
bud--