I've read about the importance of grounding when using surge protectors.
I've got a few surge protectors that have those "GROUNDED" indicators (APC has it as part of its "SITE WIRING FAULT" indicator). So if the GROUNDED indicator is lit (or if the SITE WIRING FAULT indicator is not lit), then does that mean that I have adequate grounding?
(I've noticed that some, but not all, of the outlets in my house will cause the GROUNDED indicator to not be lit.)
Which ground? If a surge protector connects to motherboard ground, then will the protector work? Of course not. Grounds are different for different functions. That power strip protector 'ground' is the safety ground. It says a wall receptacle safety ground connects to breaker box safety ground bus. Completely disconnect the building's earth ground and that ground light would still shine brightly.
Protectors are only as effective as their earth ground. Furthermore, the connection to earth must be short, not bundled with other non-grounding wires, no spliced, no sharp bends, etc. Clearly that safety ground detected by the power strip does not make any good connection to earth ground.
For example, if trying to earth a surge down that safety ground wire, then the surge is induced on all adjacent wires. What kind of protection is that?
Effective protector is located at the utility service entrance (ie circuit breaker box) to make a less than 10 foot connection to 'earth' ground. A protector is only as effective as its earth ground. To sell ineffective protector, those plug-in protectors must confuse all grounds as same. No earth ground means no effective protection. While no earth ground may exist, that protector light shines bright.
In the meantime, that earth ground connected by a 'whole house' protector is the secondary protection system. Also inspect the primary protection system - a different ground:
Notice the plug-> I've read about the importance of grounding when using surge protectors.
Assuming that the "turns ratio", i.e. the conductors are parallel so the induced current and voltage is 1:1. If the surge is a low voltage, high current surge then the low induced voltages in other conductors would not be harmful. So your question "What kind of protection is that?" has an answer of _adequate_.
You've posted a lot of informative information on this subject in the past but as far back as I can remember you have never given any references. To others who are uninformed on this subject much of what you say seems to be just speculation and hearsay.