Apparently you did not design surge protectors. And did not learn from MOV manufacturer application notes.
Neither do you from numerous erroneous forum posts.
Provide specification numbers for that filter. It is typically inferior to the first filter found in properly designed power supplies. Superior filtering is part of better protection already inside properly designed electronics. Even the power supply, with many filters, has a better in its first filter.
This is a pretty broad comment it is it not? You also don't mention which specification numbers and also assume it is built in to power supplys. Pretty broad assumptions.
So what does that filter do? The protector is undersized. A technique for keeping a protector from creating a fire is to filter incoming power to MOVs. It is an old design technique even discussed in MOV manufacturer application notes. Then a sharp transient (a surge) is blunted; is less likely to turn the MOV into a flaming candle.
Considering a filter isn't a "protector" or "MOV," No one has any idea what this incoherent sentence actually means. Those whole home protectors you keep running on about are the same basic design as plug in protectors. They are just larger.
Among protectors listed in the APC recall is at least one that has filters. Even with multiple inductors, the APC PRO8T2 is still on the CPSC list of protectors that must be removed immediately due to that human safety threat (fire).
Yeah all 755 incidences out 15million sold and recalled units. 0.0000503% chance of an incident. You realize that whole home units can catch fire and burn also right?
No protector stops or blocks(filters) a surge. A relevant EE concept (taught to first semester engineers) is current source. That means anything that might stop or block a surge (ie a filter) causes voltage to increase so that current can blow through that filter. A near zero filter in protectors does virtually nothing to protect appliances. Meanwhile superior filters are already inside properly designed electronics as even required by numerous codes and standards.
Bud here has quoted all of the codes, you chose to ignore them and the science behind it. This same statement (which is incorrect) applies to your whole home protectors since they are the same design as plug in strips. Again, a filter isn't a surge protector. It is obvious that bryanl gets this but you don't seem to so no one knows what you are arguing. Also, it is obvious that you have never been to EE school or even understand the basic EE concepts from your numerous posts here. Voltage is potential. Current is a load. They are related via resistance. Current is drawn, not pushed. A MOV operates by connecting the hot leg to neutral or ground (or both, design varies) when voltage rises above a certain threshold as designed in to the MOV. This causes a high current to be developed due to the MOV placing a low resistance path to ground or neutral which drives current up and pulling voltage down. You can see this effect every time you start your car. Everything in the car dims down because the starter motor provides a low resistance path back to ground and voltage sags sometimes to less than 10volts from 12.5v. Same thing happens when you fire up an air compressor in the garage, the brief dimming of lights is caused by a voltage dip.
That protector filter is in combination with a thermal fuse to avert a house fire. And still those APC protectors were creating fires. Because the APC (like Tripplite, Monster, Panamax, etc) is more about profits; less about protection. Even its spec numbers say near zero protection.
The MOV suppressor may have a thermal fuse. You are technically correct that the filter has a thermal fuse also. It is called a circuit breaker since filter is not part of the surge suppression circuits and would only be overloaded by to much current draw.