RMS Voltage High or Low - If the RMS voltage goes high or low by a certain percentage defined by the user in UPS View. The UPS will discharge and a message will appear in the logfile.
Fast Voltage Transient - The UPS is constantly monitoring the voltage coming from the utility, on the order of once every 52 microseconds. If the voltage spikes above or below a certain range, specified by the user. The flywheels will discharge to correct the voltage and a message is sent to the logfile.
Frequency High or Low - The UPS is constantly monitoring the frequency of the utility power. If the UPS determines, that the frequency is out of the user specified range. The flywheels will discharge to correct the frequency and a message will appear in the logfile.
DC Bus High or Low - The UPS is constantly monitoring the DC Bus of the UPS. If the DC Bus voltage fluctuates beyond user specified limits, the flywheels will discharge and a notice will be sent to the logfile. The user can specify the ranges and percentages relating to each of these flywheel discharge modes in UPS View under "Menu - Op. Params".