Tripp Lite Isobar Ultra 8-Outlet Surge Protector Power Strip w/ 12' Cord Expired

just a suggestion... if you are spending this much money
on some glorified surge protector, you may as well buy a;
https://www.amazon.com//dp/B00009RA60
line conditioner, which is superior to ANY surge suppressor
as it also adds brown out protect which is very common.
these will remain effective forever, while surge protectors
lose their their rating over the years. i bought this 600w
https://www.youtube.com/watch?v=29MBmnGYBQo
30 years ago for $100 and it's been flawless ever since,
protecting all my home network and AV equipment.

I've read about this before but it's been a long time, so I don't remember most of the details. I believe there are different ways they get rated, which is why you see differences between the specs and the numbers stamped on the back of the units. There's also the issue of what absolute voltage they clamp at and how much excess voltage they let through before clamping. You have to remember that 120V RMS has a peak of 170V. You can't have a clamping voltage lower than the peaks of the sine wave, or else it would clamp on every cycle.

Additionally, as MOVs (the surge protection component) wear out, the clamping voltage drops. If/when the clamping voltage drops below the peaks of the sine wave, it will start clamping when there is not a surge, leading to a positive feedback loop and thermal runaway. This is one of the reasons surge protectors sometimes catch fire. Modern surge protectors are required to have thermal fuses, to reduce the likelihood of this. The point is, all else being equal, a MOV with a lower clamping voltage will fail quicker than one with a higher clamping voltage. It will both be suppressing milder surges and have less room for degradation before failure.

As you brought up, the clamping voltage (and joule rating) can also be different between legs. Unlike hot-neutral and hot-ground, neutral-ground should have less/no difference in potential between them (0V). This is not always the case, especially in improperly wired circuits. The level of protection provided does often differ between the various legs. Surges are less likely neutral-ground, so there's usually less protection there. Hot-neutral and hot-ground are the bigger concern.

As for the product you linked, it looks like a slightly lower end unit. It doesn't appear to be of their flagship Isobar/Isotel line. It lacks the isolated filter banks and metal casing. It may also have weaker surge protection. It does have RJ11 (telephone) protection but not many people still have conventional landlines. I would spend the extra on the Isobar in this deal.

This is not correct and even the video you linked partially mentions it. Line conditioners (and UPSs) use the same sacrificial MOVs as surge protectors. Not only that, they often have fewer than you'd find in a good surge protector. The unit in the video only appears to have 5 MOVs. I've seen high end APC and Tripp-Lite surge protectors with at least 6-10. That also doesn't get into the joule rating and clamping voltage, which can also be better in a good surge protector.

People often overestimate what a line conditioner or UPS does, probably due to good marketing. A line conditioner is usually simply a mediocre surge protector combined with a 2 or 4 stage AVR. As demonstrated in that video, that model has 4 discrete AVR modes (2 boost and 2 buck). This will boost or trim the incoming voltage by a certain percentage. As he shows, it does NOT guarantee a constant 120V. An AVR is really only useful if use experience frequent, prolonged mild/moderate undervoltages or overvoltages and have equipment that is sensitive to them. Many modern switching power supplies are already designed to accept voltages in this range. I don't think line conditioners are particularly useful for the average person. Depending on your needs, a good surge protector or a UPS is likely a better choice.

Unless they've changed, the Tripp-Lite Isobar Ultra is a high quality point-of-use surge protector. Like most other surge protectors you see for sale, it does use sacrificial MOVs that WILL eventually fail (even if it takes decades). If you want something that should last forever, you need to shell out big money for a series mode surge protector. Those are uncommon and expensive (I think about $200 for the most basic model).

For protection from surges originating from outside the house, a whole-house surge protector is the best choice. These provide far superior protection, due to their proximity to earth ground. Point-of-use surge protectors are still a good idea for surges originating inside the house.



If you're going to do that, it would be preferable to do it the other way around. Plug the power conditioner into the surge protector.