Reliability; Figure 3 System Control Cabinets - Liebert 1000kVA Operation & Maintenance Manual

Figure 3 System Control Cabinets
Types of System Control Cabinets (SCCs)
• SCCT—A stand-alone cabinet containing system control logic for up to six UPS modules, a static
bypass switch, manually operated disconnects for the static bypass switch and two motor-oper-
ated system circuit breakers.
• SCCI—System control logic and static bypass switch are integrated into a switchboard cabinet
manufactured by others, which also includes the system circuit breakers.
• SCCC—An integrated configuration like the SCCI, but with a static switch rated for continuous
duty.
1.2

Reliability

Reliability is the most important design goal for Uninterruptible Power Systems. Liebert Series 610
UPS systems have demonstrated reliability by achieving a field-proven critical bus MTBF in excess of
2 million hours. In addition, our Quality Assurance program is certified to the requirements of
ISO 9001 standards.
Liebert Large UPS systems are ETL listed to the requirements of UL 1778. All equipment and compo-
nents are manufactured to applicable UL, NEC, NEMA, ANSI, IEEE and CSA standards and guide-
lines.
Designed for Success
The keys to reliability in the design of the UPS system are using conservatively rated components,
minimizing transfers to bypass, making operator controls understandable and providing easy access
for maintenance and repair. Liebert UPS systems lead the industry in all these areas.
For example, the Series 610 can handle substantial overloads through the solid state static bypass
switch without transferring to the bypass source. By minimizing transfers to bypass, the Series 610
minimizes operation of motor-operated circuit breakers and enhances system reliability.
As another example, the system control logic has been packaged into digital control logic to eliminate
the failure-prone discrete logic boards used in other brands of UPS products. Furthermore, the logic is
isolated from heat-generating components to ensure optimal operating temperatures.
4
Introduction