APC 990 User Manual

Page of 32
Symmetra MW with External Bypass Static Switch Operation Manual - 990-1377D-001
21
Maintenance
Predictive Maintenance Screens
The Predictive Maintenance screens display the stress status and the Expected Remaining Lifetime (ERL) 
of the critical components of the Symmetra MW UPS system.
Warning: Only personnel trained in the construction and operation of the equipment, 
and the electrical and mechanical hazards involved, may install or remove system 
components.
How to access Predictive Maintenance screens
Inverter DC Capacitors screen
The Inverter DC Capacitor screen displays the actual status and Expected Remaining Lifetime (ERL) of 
the Inverter DC Capacitors. You can sort the data by pressing any of the column labels.
• Stress Status: Shows the actual status of the 
Inverter DC Capacitors. The possible values 
are:
– Normal (displayed in green)
– Stressed (displayed in yellow)
– Major Stress (displayed in red)
• ERL (months): Predicts the expected 
remaining lifetime of the particular 
component.
Press the Operation button in the bottom 
left corner to access the Operation screen.
Press the Predictive Maintenance button to 
access the Predictive Maintenance screens.