On Thursday, May 19, 2016 at 6:03:02 AM UTC-4, philo wrote:
Not really. A surge suppressor is simply an MOV which will shunt voltage
spikes.
And where does it shunt those spike to? If not connected low impedance (ie less than 10 feet) to single point earth ground, then it must shunt those spikes elsewhere - such as destructively through adjacent electronics.

Protection is always about where energy dissipates. If a protector is adjacent to an appliance, it can only protect by 'blocking' or 'absorbing' that energy. How does its 2 cm part 'block' what three kilometers of sky could not? It doesn't. How does its hundreds of joules absorb surges that can be hundreds of thousands of joules? It doesn't. And does not have to. A surge too tiny to destroy appliances can also destroy near zero plug-in protectors. Then the naive consumer uses wild speculation to assume, "My protector sacrificed itself to save my computer."

More robust protection already inside appliances protect those appliances. Near zero joule protectors fail to even promote more sales.

A properly earthed 'whole house' protector does not 'block' or 'absorb' anything. It connects hundreds of thousands of joules harmlessly to what does all protection - single point earth ground. Then even near zero plug-in protectors are protected. Then near zero plug-in protectors can protect from other and tinier anomalies.

Plug-in protectors are only useful if used in conjunction with properly earthed 'whole house' protection. Protection is always about where hundreds of thousands of joules are harmlessly absorbed. Any solution that does not discuss that energy is best considered a scam.

MOVs are effective when connected low impedance (ie less than 10 feet) to what actually does protection - single point earth ground.