Model Cdp

Model Cdp

Can a cheap UPS easily damage equipment with power adapters?

Look at this amazon review about this person's experience: http://www.amazon.com/gp/cdp/member-reviews/A2GY9CISMBIVWE/ref=cm_cr_pr_auth_rev?ie=UTF8&sort%5Fby=MostRecentReview That's the model I want to get but I plan to plug in my internet modem and router (both of which have power adapters) to keep my internet connection alive in case of an outage.

However, if cyberpower's warranty states in microprint somewhere that it's not responsible for damage done to devices with power adapters because it's not a true sine wave UPS...well then I won't be interested in buying one anymore.

This is a qualified yes. A square wave or a modified sine wave inverter (which is just a square wave with a dead zone to make its peak and RMS voltages the same as a sine wave), can burn out inductive components, especially ones with thin wires, but may not in some cases. They (the wall adaptors) were never intended for this operation, but it is possible that lightly loaded ones or ones that have this issue taken into account have no problems. The reason is that the reservoir capacitor charges more quickly than it would with a sine waveform, so draws a heavier burst of current. Also the square waves can cause "ringing" voltage peaks in the transformer which may confuse some systems, or even cause insulation failure. With audio-video systems the square wave inverters are more likely to generate interference.

It seems cheap insurance to me to use a true sine inverter, in that true sine inverters doesn't cost much more, are lighter in most cases, and in fact potentially cheaper. Only one wall pack failing means you need a new inverter to solve the problem, as well as a replacement wall pack and maybe more as in the link. Wall adaptors that use switch mode operation instead of an iron core transformer probably have few problems. AC motors in general, but especially shaded pole and single phase induction types with capacitor start are also a problem.