re: Surge Protector/ Power Strip for Home office recommendations?

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Surges coming from the inside of a home cannot be prevented by any SPD and likely can't protect anything due to small wiring in branch circuits.

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So much is wrong with that statement that I hardly know where to begin.

If surges exist inside a house, then GFCIs, furnace controls, dishwasher electronics, dimmer switches, LED & CFL bulbs, and smoke detectors are replaced daily. How many have you replaced this week or this decade? That tiny number says no surges are created inside. At most, only noise. That myth is invented / encouraged by ineffective protector manufacturers to scam naive consumers.

How often is your central air and garage door opener creating well over 330 volt spikes on 120 volt circuits? First, if they are, then nearest electronics are first destroyed. IOW that central air or garage door opener is first damaged. Then other appliances damaged by a surge that occurs daily.

If that spike exists, then tiny joules inside protectors are first to fail. How many protectors were damaged this week by daily generated spikes?

And finally, if those spikes exist, then one 'whole house' protector eliminates them. To make a myth work, they need you to wish a protector only works when between a surge source and appliance. Protectors that work that way (that magically 'block' or 'absorb' a surge) are tiny joules - ineffective - fail on a first surge to increase sales and profits.

A sacrificial SPD violates what protector part manufacturers state must not happen. Catastrophic failure is a reason for protector fires. Absolute Maximum Parameters define numbers for unacceptable operation - catastrophic failure. Any protector that fails catastrophically was doing no appliance protection. And is also a threat to human life.

That plug-in protector probably has a "Protector Good" light. That light can never report the acceptable failure mode - degradation. It only reports an unacceptable failure - catastrophic. IOW that light says a protector was so undersized that emergency protection circuits (ie one amp thermal fuse) were activated to protect human life.

Why does a failed protector still power appliances? Because its protector parts were disconnected as fast as possible to avert fire. And that same surge remained connected to attached appliances. That same surge (that destroyed a tiny joule protector) was too tiny to overwhelm better protection inside the appliance. The appliance was never disconnected from that surge - that was too tiny to damage the appliance.

UL is only about protecting human life. UL 1449 only tests a protector enough to demonstrate it has protector circuits. That protector can completely fail on those tiny C.62 test transients - and still be UL approved. They don't care that it is grossly undersized - poor quality. They only care that it does not spit sparks and fire if / when it fails.

Joules define every plug-in SPD design. Read MOV datasheets before making accusations. And read specification for that protector. What spec number always appears in the category that is called Surge Protection? Joules. When a protector part has more joules, then more current is necessary to exceed its joule number - cause catastrophic failure. Apparently you did not design these things. Did not read datasheets. And did not routinely trace surge damage to discover what human mistake permitted a surge current inside.

Not surge voltage. Surges are a current source - not a voltage source. Electrical engineers know why that difference is so significant.

One who does surge protection spend most time discussing the number one critical item in all protection systems. Some protection systems do not even have protectors. But every one features this: single point earth ground.

Case studies from peers who do this stuff. In this case a Nebraska radio station suffered repeated damage. Then electrical engineers, who never understood this stuff, even disconnected earth grounds assuming that was causing repeat damage.

What did the professionals do to avert all future damage? They installed no protectors. They upgraded the item that defines all protection - earth ground: LINK

Orange County FL suffered repeat damage to 911 Emergency response equipment. They finally brought in informed professionals. Again, no protectors were installed. They fixed the reason for repeat damage at many locations. They fixed improperly installed, defective, or undersized earth grounds: LINK

Another professional describes why they do not suffer surge damage:

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Well I assert, from personal and broadcast experience spanning 30 years, that you can design a system that will handle *direct lightning strikes* on a routine basis. It takes some planning and careful layout, but it's not hard, nor is it overly expensive. At WXIA-TV, my other job, we take direct lightning strikes nearly every time there's a thunderstorm. Our downtime from such strikes is almost non-existant. The last time we went down from a strike, it was due to a strike on the power company's lines knocking *them* out, ...

Since my disasterous strike, I've been campaigning vigorously to educate amateurs that you *can* avoid damage from direct strikes. The belief that there's no protection from direct strike damage is *myth*. ...

The keys to effective lightning protection are surprisingly simple, and surprisingly less than obvious. Of course you *must* have a single point ground system that eliminates all ground loops. And you must present a low *impedance* path for the energy to go. That's most generally a low *inductance* path rather than just a low ohm DC path.

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And yes, we often went into facilities after damage happened to demonstrate and correct human mistakes (ie plug-in protectors) that did no protection or even made damage easier.

In one classic case, plug-in protectors earthed a surge destructively through an entire network of powered off computers. We literally replaced every damaged semiconductor to trace that surge path and to fully restore all computers. But then we had to submit our analysis and conclusions also to design reviews.

Even the popular internally generated surge is a myth as demonstrated by so many reasons why - only some already posted.

Plug-in protectors should never be used if a 'whole house' solution does not exist and connected to single point earth ground. Then the 'whole house' protector does (according to the IEEE) 99.5% to 99.9% of the protection. And a plug-in protector can do an additional 0.2%. Yes, a plug-in protector can do some protection ... only if a properly earthed 'whole house' solution exists.

UL is only about protecting humans. UL is never about performance of hardware. It only defined what is necessary to protect humans. Plug-in protectors that have near zero protection (near zero joules) can have a UL listing as long as its failure does not threaten human life - ie create fires during testing.

Since a surge, too tiny to damage appliances, also destroys that tiny joule protector, then the "sacrificial protector" myth lives on. Effective protectors (if properly earthed) do not fail for many decades even after many direct lightning strikes. Also also protect from a mythical, internally generated surge.

A 200 or 400 joule protector means a protector can fail on surges too tiny to damage any appliances. As long as that joule number is above zero. then advertising can hype it as 100% protection. Lying subjectively is legal.