Testing is key to maintaining a well-functioning normal power system as well as preventing future problems. Examples of normal power system functional-performance testing can include:
- Testing individual equipment, such as medium voltage (rated above 600 volts) switches and transformers, medium voltage switchgear, unit substations, low voltage transformers (rated 600 volts and below), low voltage switchboards, local and remote meters, circuit breakers, motor controllers, motor control centers, panelboards, individual motor starters, uninterruptible power supplies and installation conditions.
- Testing subsystems, such as power monitoring and control systems, supervisory control and data acquisition (SCADA) systems, switchgear (both medium voltage and low voltage) automatic control systems, power conditioning systems, grounding and bonding systems, insulation resistance and ground fault alarm systems.
- Testing normal operations, startup, shutdown, failures and other emergency conditions. Simple switchgear lineups are tested to verify all desired operating conditions, including manual and automatic operation tests for all potential operating conditions. Additional types of tests should include key interlocking devices that permit manual switching while prohibiting dangerous paralleling connecting together live sources. More complex switchgear lineups are tested to verify correct response to power interruptions with multiple failure scenarios.
Often, the building mechanical loads will not be sufficient to verify system ability to operate at full, rated load. In those cases, large and small load banks may be used so that specified power system requirements can be verified.
- Testing the integration of new equipment and systems into existing systems for renovation and infrastructure upgrade projects.
The electrical power systems portion of the American Society for Health Care Engineering’s (ASHE’s) Health Facility Commissioning Handbook and the electrical power systems portion of the ASHE Health Facility Commissioning Guidelines provide more detail on these topics.