Understanding UPS Operation

If the input power fails to return or is not within the acceptance windows required for normal operation, the battery continues discharging until a DC voltage level is reached where the inverter output can no longer support the connected loads. When this event occurs, the UPS issues another set of audible and visual alarms indicating SHUTDOWN IMMINENT. Unless the rectifier has a valid AC input soon, the output can be supported for only two minutes before the output of the system shuts down. If the bypass source is available, the UPS transfers to bypass instead of shutting down.

If at any time during the battery discharge the input power becomes available again, contactors K1 and K5 close and the rectifier begins to supply DC current to the converter and inverter. At this point, the unit returns to Normal mode. Depending on the total load and the duration of the battery discharge, battery current limit alarms may be seen for a short time due to the current required to recharge the battery.

The system’s total operating time on battery depends on many factors. Some factors that affect battery support times are battery type and capacity, number of parallel strings, environmental temperatures, age of the battery, and fluctuations in load demand during the discharge. The greater the load, the less support time the battery has. Decreasing the load generally increases the battery support time.

7.3 Multiple Module Parallel System

Parallel operation extends the normal operation of Powerware 9390 UPS units by offering increased capacity and/or redundant capability. The parallel system continues to maintain power to the critical loads during commercial electrical power brownout, blackout, overvoltage, undervoltage, and out-of-tolerance frequency conditions. See Drawing 164201535-4, sheets 3 of 5, 4 of 5, and 5 of 5 in Appendix A, for a detailed relationship of the parallel system.

The output of the system is normally supplied by several uninterruptible power modules. Multiple UPMs are connected with their outputs in parallel (tied together) to provide a load level greater than the rating of one UPM and/or for redundancy. The paralleled UPMs supply the output load with protected power as long as the load does not exceed the combined rating of the paralleled UPMs.

The power system is redundant as long as one of the UPMs can be disconnected from the output bus and the remaining UPMs can continue to supply power to the load without exceeding their ratings.

When the load is being supplied by the UPMs, the system output bus is continuously monitored for an overvoltage or undervoltage condition. If an out of limits condition is detected, the paralleled UPMs transfer the load to bypass using the UPM static switches.

Communication is required between the UPMs for system metering and mode control. System level communication and control are accomplished using a Computer Area Network. A single building alarm in each UPM, connected to the other UPMs in parallel, and tied to the bypass contactor auxiliary contacts in each UPM are used for a secondary communication path. This arrangement ensures bypass control even if the CAN bus is lost.

Powerware® 9390 UPS (40–80 kVA) Installation and Operation Manual S 164201535 Rev C

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Powerware 9390 operation manual Multiple Module Parallel System
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9390 specifications

The Powerware 9390 is a high-performance uninterruptible power supply (UPS) designed for critical applications in data centers, telecommunications, and other industries requiring maximum uptime. This UPS system is renowned for its durability, efficiency, and advanced technological features, making it an ideal choice for environment-sensitive operations.

One of the standout characteristics of the Powerware 9390 is its modular architecture. This design allows for scalability, enabling businesses to tailor the power supply to fit their specific needs. Users can add or remove power modules as demand fluctuates, ensuring optimal performance without overspending on unnecessary capacity. The system is available in various power ratings, typically ranging from 40 kVA to 750 kVA.

Among the key technologies utilized in the Powerware 9390 is the Advanced Battery Management (ABM) system. This innovative feature helps extend battery life by monitoring and optimizing charging cycles. The ABM technology uses an intelligent three-stage charging process, significantly reducing battery wear while ensuring high availability of power during outages. This enhancement not only improves reliability but also lowers maintenance costs over time.

Energy efficiency is another hallmark of the Powerware 9390, as it incorporates double-conversion technology to maintain voltage stability. This ensures that sensitive electronic equipment is protected from surges and fluctuations in power supply. Additionally, the UPS offers high input power factor and low harmonic distortion, contributing to overall energy savings while minimizing the environmental impact.

The Powerware 9390 is equipped with advanced monitoring and management features that allow users to maintain complete control over their power infrastructure. An intuitive LCD display provides real-time metrics on system performance, battery status, and operational logs. Furthermore, the UPS can be integrated with network management systems, enabling remote monitoring and management via web interfaces.

In terms of safety characteristics, the Powerware 9390 adheres to rigorous industry standards, ensuring that it provides reliable performance under various operating conditions. Its robust construction and redundant components further enhance reliability, making it a popular choice in mission-critical environments.

In conclusion, the Powerware 9390 stands out as a leader in the UPS market, combining modular scalability, advanced battery management, energy efficiency, and robust safety features. Its ability to adapt to the needs of dynamic organizations while providing reliable power protection makes it an invaluable asset for any critical application. With its state-of-the-art technologies, businesses can depend on the Powerware 9390 for continuity, efficiency, and peace of mind.
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