When the city power fails, the UPS takes over running the equipment. The time for operation can be minutes or hours before the battery is exhausted. Add to this, the air conditioning in the room is probably inoperative and your gear is getting hot.
The Mini Power is an analogue sensor that enables a CM range climate monitor to detect line voltage and send an alert through email, SNMP trap or (optional) SMS if power is lost. This provides time to either restore power or properly shutdown the system before backup power is fully utilized.