Quote from: Subw on September 05, 2015, 10:49:36 PM

You assert that any surge seen on input of such UPS coming through AC->DC->AC transformation survives and comes out in original form??

I assert nothing. That is engineering fact using concepts such as superposition. However let's assume you need information based only in hearsay. Well, this cite is famous for describing effective protection with numbers. But we will not provide those numbers. Instead we will only provide same logic that somehow proves a double conversion UPS does protection.

Quote

With this high percentage of power disturbances attributed to transient voltages, it is important to note there are several instances when these transients can bypass a UPS or Stand-by system, or pass directly through them to potentially damage the attached equipment.

That well understood quote from Polyphaser (an industry benchmark known only to the few who really understand surge protection) should be obvious.

That simply repeats, in subjective terms, what has always been known about a UPS - double conversion or otherwise. Anyone can read its specification numbers. That surge protection is obviously near zero. And sold to naive consumers as 100% protection - because those consumers routinely ignore facts and numbers.

You have zero reasons to believe a UPS provides any effective protection. That double conversion UPS is a direct connection from the surge source to electronics. Since you did not learn basic and relevant concepts (current source, equipotential, conductivity, impedance, etc), then you are easily scammed with myths that are technically bogus.

What is a battery in an AC-DC-AC conversion? A direct short - had you learned basic electrical concepts taught to first year engineers. That is the point. They easily scam using half truths and lies - that no technically trained person would fall for.

Please post one specification number that proves any double conversion UPS provides that protection. They know a majority of adults are easily scammed by always ignoring specification numbers.