Operation

6.0 OPERATION

! WARNING

Hazardous mains and / or battery voltage present behind covers.

No user-serviceable parts are located behind covers that require a tool for their removal. Only qualified service personnel are authorised to remove such covers.

6.1Introduction

The Liebert NXa Uninterruptible Power System is connected between the Mains AC input source and the critical load to provide uninterruptible power to the latter. The power from the UPS is free from voltage and frequency variations and from disturbances experienced at the Mains AC input supply.

This is achieved through high frequency double conversion power pulse width modulation (PWM) associated with full digital signal processing control (DSP).

As shown in Figure 63, the AC input mains source is supplied at Q1 and converted into a DC source. This DC source feeds a DC/DC Bidirectional Battery Converter (that ensures the battery to remain charged at all times) and at the same time feeds the Inverter that converts the DC source into a clean and input independent AC source. The battery powers the load through the bidirectional battery con- verter and through the inverter in case of an AC input mains power failure. In case of Inverter unavailability or excessive overload, the load may also be powered from an external AC Bypass source through input isolator Q2 and the static bypass. Besides this, if maintenance or repair of the UPS is necessary, the UPS can support the load through the internal and manually controlled maintenance bypass isolator Q3. With the exception of the maintenance bypass isolator, all the isolators shown are closed during normal UPS operation.

Figure 63 Single unit block diagram with split-bypass input

Bypass

Mains

Supply

N

Maintenance Bypass Isolator Q 3

 

 

 

UPS Module

 

 

 

 

 

Bypass Isolator Q2

 

 

 

 

 

Bypass Side

 

 

 

 

 

DC Bus

Inverter

 

 

 

 

 

 

 

 

 

 

Static Switch

Rectifier

Input

Mains

Supply

Input

 

Isolator

Input

Q1

Static

 

Switch

Battery

Output

Isolator

Q5

UPS

Output

Converter

1

Battery

CB Circuit Breaker

2

Battery

75

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Emerson 50 and 60 Hz DC Bus Inverter Static Switch Rectifier Input Mains Supply, Battery Output Isolator, Bypass Side
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30-200kVA, 400V, 50 and 60 Hz specifications

The Emerson 400V, 50 and 60 Hz, 30-200 kVA is a robust and versatile power solution designed for various industrial and commercial applications. This equipment delivers a reliable source of power, ensuring operational continuity and efficiency for numerous critical systems.

One of the standout features of the Emerson 400V series is its exceptional load handling capability. With a kVA range of 30 to 200, it can cater to both small-scale operations and larger enterprises, making it a flexible choice for businesses looking to scale their operations. The dual frequency capability of 50 and 60 Hz allows the system to be utilized in various geographical locations, accommodating different regional power standards.

The series is built with advanced power electronics technology, resulting in a highly efficient energy conversion process. This technology not only boosts performance but also reduces energy losses, leading to significant cost savings in operational expenditures. Moreover, the Emerson 400V solution is designed with an emphasis on minimizing harmonic distortion, ensuring that it meets stringent regulations and preserving the integrity of sensitive electronic equipment.

Another critical characteristic of the Emerson 400V series is its modular design. This allows for easy upgrades and maintenance, ensuring that businesses can adapt their power solutions as their needs evolve. The system features a user-friendly interface for monitoring and managing power loads, enhancing operational oversight.

Additionally, the Emerson 400V series emphasizes robust safety features to protect both equipment and personnel. Integrated protection mechanisms, such as overload and short-circuit protection, provide peace of mind and safeguard against potential power-related incidents.

In terms of physical design, the unit is built for durability, capable of withstanding harsh operating environments while maintaining performance integrity. The compact footprint ensures that it can fit into various spaces without sacrificing power output.

Overall, the Emerson 400V, 50 and 60 Hz, 30-200 kVA system represents a comprehensive power solution that combines high efficiency, adaptability, and advanced technology, making it an ideal choice for organizations aiming for reliable power management and operational excellence.
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