Will UPS burn in those cases? Is the mains voltage exceeding the input voltage range? Or because the load percentage is too large?
In addition to the load over the General Assembly has the possibility of burning UPS
There are other such as: UPS internal components life expectancy and so on
Under normal circumstances
UPS itself component quality or component aging,
There are environmental or dust,
Are likely to burn the phenomenon.
Large brand of UPS beyond the input voltage range will not burn, with a large percentage of load will not burn. Because UPS has a self-protection function. Voltage, load out of range UPS does not work. 90-270 access 380UPS does not work. Will not burn. Unless you sell fake. General burn is the aging of components, or internal dust, static and other UPS internal reasons. Cottage UPS I do not know. 380 input with 220 electricity will not burn, the voltage is too low when the battery-powered UPS work properly.
Are generally overloaded, the input of course, there may be, but the UPS input upper and lower limits are large. Is usually okay. General UPS load can not be over 80% is best 50%. So as to ensure safe and normal electricity.