joule is the unit quantifying energy, whether of electric, explosives, or _______!
when Anaconda W&C analyized the capability of 15kv shield systems in 1971, the elec energy was converted to joules -- the tech with me observing the actual tests done at ABChance company just north of Columbia MO stated that the sound of the cables failing within conduit sounded to him like 105mm howtzer shell explosions he experienced in WWII. we produced one fireball in excess of 15ft in diam due to shorting a cable in an open ditch, simulating a digin. electrocution would be instant -- burning in such a fireball would be horriable.
The higher the joule rating for the surge protector, the more energy it will divert before the protector failure.
Understand that not much will withstand a direct hit by lightning -- 1.2 million volts in 1/million second is the standard lightning simulation test voltage.
the better surge units protect L-G, L-L, L-N, have indicator lights to show that the MOVs have not shorted, have choke coils.
yes, the Belkin unit quoted is a strip type. The Panamax units I have & sold in 1988- 1995 were mostly boxes having but one outlet, but I have one with 4 outlets in a square box, prerunner of the strips.
One can buy several strips at $30 each vs $220 for whole house protectors. Besides, how many are comfortable working on the service panel? And, the whole house protectors do not seem to have the capacity of the strips. Again, get the highest joule rating, the lowest clamping voltage.