Originally Posted by acras13
If MOV based surge suppression is inferior and a fire risk , why are all the suppression devices manufactured by Eaton , Siemens , etc. Based on that technology? I may be missing something , and am happy to learn , but it just doesn't make sense to me to me that the companies that make the panels and breakers that supply the power distribution for your house or business would then offer a product that is a fire risk like the shamwow(surgex) videos showed . The surgex may kick major ass and be far superior , but the videos I saw just stunk of late night infomercial shilling snake oil .
Again , I'm not looking to say anyone is wrong or one is superior to another , just trying to learn a little more and be as objective as possible .
In many cases the whole-house units are in sealed cases, often metal, and sometimes live inside the metal service panel itself. All of that sealed metal helps prevent the breakout of sparks/heat/flames of the fried MOV.
They also use higher rated MOV's (240V RMS if not more) and are likely MUCH higher quality than the ones you find in a $10 bar.
The downside is that those also let through twice the voltage (which is probably not a good thing.)
MOV's don't protect against sustained UV/OV of say 150v RMS on a 120v RMS grid or 80V RMS.
It also doesn't protect against frequency shifts from 60hz to any other frequency.
Most UPS's protect against all 3 of those things (or they should!)
The problem with MOV's is that they conduct amperes (often to ground) when they die, or even when they reduce smaller surges. The flow of amperes causes heat in thin wires.
MOV's sacrifice themselves to save downstream stuff. It's a one-use pony that often sparks and explodes when it dies.
The dumping of electrons into the ground line causes ground contamination and raises the ground voltage from 0V to potentially high-voltage, which may cause EVEN MORE appliances to die in the house. MOV's could potentially cause more damage than a house without any.
Especially audio gear that is counting on the ground-line being at 0V and the audio signal being only a few volts higher (0.7 to 4v etc), not hundreds or thousands of volts!
Dumping power to ground at the service panel as a house-whole unit is not nearly as-bad since most of the electrons from the surge will take the shortest path to ground, which likely isn't deep into your house, but rather the grounding rod at the service panel. It still raises the ground potential though!
Supposedly the SurgeX stuff is supposed to neutralize the surge on all 3 pins (at least downstream.)
Apparently the $40 unit has everything except one thing: The 6000V surge rating.
Since it is so cheap, think I might just have to buy one to torture after I explode these APC UPS's.