5.2.4 Maintenance Bypass Mode

An internal maintenance switch (IA1) is used to safely supply utility power to the system output during periods of maintenance or repairs. Before this switch is used, the system should be transferred to bypass. This switch has two positions: “O” (OFF) and “l” (ON). When switched to “l” (ON), the bypass source supplies the commercial AC power to the load directly.

While on internal (static) bypass, when a user rotates the maintenance switch from the “O” (OFF) to the “l” (ON) position, the load is wrapped around the UPS, and power is removed from the entire upper portion of the UPS allowing service work to be completed on the UPS safely.

Figure 5–5 shows the path of electrical power through the UPS system when operating in Maintenance Bypass mode.

CAUTION:

The critical load is not protected while the UPS is in the Maintenance Bypass mode.

DANGER:

LETHAL VOLTAGE PRESENT: This unit should not be operated with the cabinet doors open or protective panels removed. Do not make any assumptions about the electrical state of any cabinet in the UPS system.

Maintenance Bypass Mode

 

 

 

IA1

 

 

 

 

K4

 

Static Switch

 

 

 

K1

Input Filter

Rectifier

Booster

Inverter

K2

IA2

 

 

 

F1

 

 

 

 

 

 

 

 

 

 

 

 

 

Battery

Breaker

Contactors

Switches

Charger

Closed

 

 

 

Open

 

 

Battery

 

 

 

 

 

 

Breaker

 

 

 

Battery

Main Power

Trickle Current

Energized

De-Energized

Figure 5–5. Path of Current through the UPS in Maintenance Bypass Mode

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Powerware 9335 (80 kVA and 120 kVA) Installation and Operation

 

164201396 REV A 071103

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Powerware 9335 operation manual Maintenance Bypass Mode

9335 specifications

The Powerware 9335 is a robust and efficient uninterruptible power supply (UPS) designed to deliver reliable power protection for critical applications. Expanding upon Eaton's tradition of offering advanced power management solutions, the Powerware 9335 is tailored for environments that demand high availability and uptime.

One of the standout features of the Powerware 9335 is its double-conversion online topology, which ensures a continuous supply of clean and regulated power. This design operates without any transfer time to battery power, effectively protecting sensitive equipment from all types of power disturbances, including surges, sags, and outages.

The UPS is available in a range of power ratings, from 8 kVA to 40 kVA, making it versatile enough to support a variety of applications ranging from small server rooms to larger data centers. The modular architecture of the Powerware 9335 allows for seamless scalability, enabling users to add additional capacity or redundancy as their power needs evolve. This feature is particularly beneficial in dynamic environments where equipment and loads can frequently change.

Another significant characteristic of the Powerware 9335 is its high efficiency, often exceeding 94% in normal operation. This efficiency not only reduces energy costs but also minimizes heat generation, leading to lower cooling requirements. The UPS employs advanced technologies such as Intelligent Power Management and Smart APM (Adaptive Power Management) to optimize power usage, further enhancing its overall performance and reducing the total cost of ownership.

The user-friendly LCD display furnishes real-time data regarding UPS status, battery condition, and power settings, facilitating proactive management and monitoring. In addition, the unit can be monitored and managed remotely, ensuring that administrators can access critical information even when they are not on-site.

The Powerware 9335 also comes equipped with various connectivity options, including USB, serial, and SNMP for seamless integration into existing IT infrastructure. Additionally, advanced communication capabilities allow for integration with building management systems, ensuring comprehensive power management and reporting.

Safety is paramount, and the Powerware 9335 incorporates numerous features designed to protect both the UPS and connected equipment. This includes overload protection, battery health monitoring, and environmental monitoring, which collectively contribute to a resilient power protection strategy.

In summary, the Powerware 9335 is an exceptional UPS offering from Eaton, featuring high availability, scalability, efficiency, and robust management options. With its advanced technologies and features, it stands out as a premier choice for organizations seeking to safeguard their critical systems and data.