On May 7, 2:37 pm, VWWall wrote:
How can one find this rating for a particular device?

UL makes no effort to measure a protector's protective ability. In
fact, protectors can completely fail during a UL certification test
and still obtain UL approval. It failed without emitting sparks or
flame; therefore UL approved.

Approval may be obtained by undersizing MOV's thermal fuses so that
a protector will disconnect MOVs faster during a surge; leave the
appliance to fend for itself. Undersized surge protector simply
disconnects faster to obtain UL1449 approval. How might it get that
approval? Provide even less protection so as to not spit flame.

Also required for UL approval is total number of joules. That says
nothing about how many joules actually participate in protection.
Typically, plug-in protectors use as little as 1/3rd and never more
than 2/3rd of its joules for protection. If a protector is also for
cable, telephone, network, etc, then that protector may use even less
joules during protection.

A 'whole house' protector uses all joules during all types of
surges. What happens when more joules actually participate in
protection? Well, doubling the numbers of 'used' joules typically
increases a protector’s life expectancy by a factor of eight. As
joules increase, the life expectancy of the protector increases
exponentially. As joules increase, more energy gets dissipated in
earth and less energy gets dissipated inside the protector. Increase
joules to absorb less energy and to exponentially increase protector's
life expectancy.

Minimal 'whole house' protector for a home is 1000 joules and 50,000
amp surges. In locations where surges occur more frequently, a larger
joule protector is installed. Increased joules means increases
protector life expectancy.

How effective are 'whole house' protectors? Well, a friend suffered
when the 33,000+ volt transmission line fell upon his 4000 volt
distribution line. Literally everyone powered from that B phase had
electric meters explode up to 30 feet from their pans. Many had
damage to plug-in protectors and to powered off appliances plugged
into those protectors. But my friend suffered no damage, except to a
meter that exploded off his building. He had a properly earthed
'whole house' protector. A protector is not rated to provide that
protection. But properly installed protectors with sufficient joules
will provide more protection than rated.

Which protectors actually provide better protection? Products from
a list of responsible manufacturers such as Intermatic, Square D,
Siemens, Polyphaser, GE, Cutler-Hammer, Keison, and Leviton.
Specifically not on that list are APC, Tripplite, Belkin, and Monster
Cable.