Is the "Protection Working" light on power surge protectors a reliable indicator of a working unit?

Thread Starter


Joined May 18, 2011
I have had a Power Surge Supressor APC P6B for a long time, it says it is rated for 840 Joules.
I was wondering if it is at all reliable due to its age and read in its manual that the light on it called "Protection Working" means that:
"When the power switch is turned on, the green 'Protection Working' indicator illuminates to tell you the surge protector is capable of protecting your equipment from harmful electrical surges. Your equipment will be protected even when the surge protector's power switch is turned off. If the indicator does not illuminate when the power switch is turned on, the unit has sustained damage and is no longer capable of protecting your equipment."

Is it really as simple as just looking at that light to have a semblance of security when using it, even though it is very old and newer models are rated for so much more...

Are power surge protectors like computer power supplies in the old days where it didn't matter what the "number of watts" label said - it mattered more how reliable the brand was...
It's funny you mentioned APC. I had one where an internal thermal fuse opened and the staus was "unprotected". Unfortunately, it means that if the thermal opens, the surge is passed to the equipment. I don;t think that is very nice. The APC surge suppressor looks like a semi-circle and some outlets support wall warts. The construction is total plastic and this one actually cracked. For whatever reason, it was recalled and replaced.

What matters is the connected equipment warranty AND you have to save the receipt. No receipt. No warranty.

I do like the Trip-lite ISOBAR series. e.g.

the APC was lacking this:

Premium Safety Features
Automatic shutoff permanently cuts power to outlets if protection circuit is incapacitated, preventing
equipment damage and indicating replacement is required

and the metal construction amoung other things.

Usually the protection devices short rather than open. Degradation surely is possible, but the WARRANTY and the RECEIPT matter. I did have one blow up and was covered in black soot. Warranty covered the really expensive computer monitor at the time. (used to be called ONEAC) has some youtube videos that actually use the Tripp-lite ISOBAR as an example and they prove that the ISOBAR is not sufficient protection. They claim, power protection has to include an isolation transformer. It's wired not to isolate the ground, but to clean it up.

I was at a demonstration of the power conditioners and I was sold. So, the "conditioner" was not a "surge suppressor". I combined both like they suggested when it became imperative that an obsolete computer system was to be kept running. It reduced problems to 8" floppy drives, dust and the power supply.

I then moved that suppression technology to a Macintosh system that was on nearly 24/7, but used maybe 8-10 hours a day. In the 17 years, that system was in service, dust and a bad floppy were the only problems. The SCSI hard drive was still going after 17 years.

It moved to the next upgrade. Two other systems got the same treatment.

isn't a bad initial video.

There is a part 1
, part 2 and part 3 video.