However, of 7 APC surge protector strips, five were damaged. On one or two, the "loss of protection" light was illuminated. The rest appeared normal. However, when I physically opened the cases, electronic components were obviously badly damaged, and there was evidence of smoke and melted plastic inside. All of our battery backups were fried as well, these were APC as well.
A destructive surges was both incoming to and outgoing from all protectors and computers simultaneously. If a surge is incoming to the protector strip, then that same surge was also outgoing into each computer. First that surge flows everywhere simultaneously in that path. Much later something in that path fails.
Generally, protection already inside computers is superior to protection inside power strips. So what failed? Weakest protection. Making that protector undersized got you to recommend it. A surge too tiny to harm the computer easily damaged an undersized protector.
Effective protection means a protector does not fail. In your case, the word fire should cause you concern. A NC fire marshal describes their fire house fire.
Recent fires involving multiple outlet devices toted as surge suppressors raised attention at the Gaston County Fire Marshal?s office primarily when
one such fire occurred in a fire station. Investigation of a fire that started behind a desk in an office revealed the ignition source was a surge suppressor. ...
Fire fighters noted fluctuations in their radio and other electronics thus started to disconnect all electronics from the system. In the office area they discovered a small fire burning behind the desk. ...
Within that firehouse, three separate surge suppressors were recovered and examined. Each had failed, the one caught on fire, another suppressor ceased working, while the third continued working but later was found to have failed internally. These findings, coupled with suspicion of suppressor involvement in other fires, prompted in-depth examination of possible reasons.
How much money for each protector? Compare that to a completely different device also called a protector. One 'whole house' protector (rated at least 50,000 amps) means everything is protected. For about $1 per protected appliance. Even a direct lightning strike does not damage a properly sized protectors. The spec number (50,000 amps) says so. Significant experience confirms it.
This time you were lucky. Protection inside all appliances was sufficient to avert damage. Unfortunately, you credited a grossly undersized protector.
A UPS is made a cheap as possible. So even it was less robust and suffered damage.
What happens inside a protector? Grossly undersized MOVs must disconnect as fast as possible while leaving that surge connected to appliances. Sometimes a thermal fuse does not trip fast enough. Resulting burned MOVs violate even MOV manufacturer specifications. MOVs must never fail catastrophically. Unfortunately MOVs were not disconnected fast enough. So some protectors were on the verge of fire. Does that get your attention?
Again, a surge catastrophically destroyed protectors while, at the same time, could not overwhelm protection already inside computers - and numerous other appliances inside the building. How many dimmer switches, GFCIs, CFL bulbs, refrigerators, and smoke detectors were damaged? Many are typically less robust than computers. What protected them?
