Chapter 10 Service And Maintenance 67
Liebert APM 90 Integrated Modular UPS User Manual
Chapter 10
Service And Maintenance
UPS system (including battery) needs regular maintenance in the long-term operation. This chapter mainly
elaborates the advice on service life, regular inspection and maintenance of UPS key components, as well as
the maintenance of UPS and the optional parts .Effective maintenance of UPS systems can reduce the risk of
UPS failure and enable longer use of UPS.
10.1
Safety
Warning
1. Daily inspection of UPS systems can be executed by people who have received relevant training, and the inspection
and replacement of devices should be operated by authorized professionals.
2. The components that can only be accessed by opening the protective cover with tools cannot be operated by user.
Only qualified service personnel are authorised to remove such covers.
3. In UPS maintenance, note that the neutral line is energized.
10.2
Key Components And Service Life Of UPS
When in use, some devices of UPS system will have shorter service life than UPS itself due to abrasion in work.
For the safety of UPS supply system, it is necessary to have regular inspection and replacement of these
devices. This section introduces the key components of UPS and the reference years of service life. For systems
under different conditions (environment, load rate, and etc.), assessment and advice by professionals on
whether to replace the device are required with reference to the information provided in this section.
10.2.1
Magnetic Components: Transformers, Inductors
The designed service life of magnetic components is 20 years. Key factors that affect their service life are
insulation system to use and temperature rise at work among windings.
10.2.2
Power Semiconductor Component
Power semiconductor components include SCRs and IGBTs. In normal UPS working state, the power
semiconductor components have no rated years of service life. SCR and IGBT failures are always caused by
other problems. However, in system service and maintenance, it is required to check on a yearly basis for
corrosion and damaged enclosure in the appearance of the power semiconductor components, and replace
those in risk of failure.
10.2.3
Electrolytic Capacitor
The actual operating life of the electrolytic capacitors is mainly affected by the DC bus voltage, capacitor
ripple current and ambient temperature of the system.
To ensure the safety and stability of the UPS system, the user must replace the electrolytic capacitors by the
end of their service life. It is recommended to replace the electrolytic capacitors after five to six years in
service.
