UPS / AC power supply for different applications

Sizing a UPS is crucial to ensure your equipment is reliably supplied during power outages or fluctuations. A wrong choice can lead to insufficient performance or unnecessary costs. The power requirement, the backup time and the sensitivity of the equipment are important.

First, you need to calculate the total power requirement. The connected load of the devices in VA or watts is added together to determine the required UPS power. The conversion factors between VA and watts are important here.

The backup time also plays a role. The longer this should be, the more powerful the UPS must be. Also pay attention to the sensitivity of your devices to power disturbances.

• Rectifier
  It converts the input voltage of 230V 50Hz (AC) into direct current (DC) for battery charging.
• accumulator (battery)
  It is the energy storage device of the UPS and is able to supply the connected devices with power in the event of a power failure.

• inverter
  It converts the direct current (DC) from the battery into alternating current (mains voltage) (AC).
• AVR (Automatic Voltage Regulator) (Line Interactive)
  It regulates the output voltage of the UPS and keeps it constant, thus preventing undervoltage and overvoltage.

• interference protection
  It removes noise spikes to protect the connected devices.
• Control electronics
  It constantly checks the mains voltage and detects voltage peaks, voltage fluctuations or voltage failures and controls the charge of the batteries. It also monitors the output for overload.

UPS (uninterruptible power supplies) devices use different waveforms, each with specific advantages and disadvantages.

• The sine wave corresponds to the natural waveform from the power grid, meets the requirements of the most modern electronics and offers a highly stable output voltage. However, UPS devices with sine waves are expensive and technically complex because they contain complicated electronics.

• The step wave represents an intermediate form between sine and square waves. Devices with this waveform are priced in the middle range and have a simpler design with less electronics. However, the quality of the stepped wave is not sufficient to operate highly sensitive devices reliably.

• The square wave is the most cost-effective option, as UPS devices require minimal electronics. However, it is not suitable for devices with inductive loads such as electric motors or printers, as the output voltage is unstable and depends on the connected devices. While the sine wave offers the highest quality, the square wave is simple and cheap, but has limited uses. The stepped wave represents a compromise between quality and price.

Disruptions in the electrical power grid can occur for a variety of reasons. Natural events such as storms, lightning and earthquakes are among the most common causes, as they can damage lines or affect equipment. Technical problems such as short circuits or scheduled power outages for grid maintenance also play a role.

In addition, human activities, such as cables being torn down during excavation work, can cause interruptions. In industrial areas, electromagnetic and high-frequency interference can affect the stability of the grid. These diverse factors illustrate how vulnerable the electrical supply network is to internal and external influences.

There are various bypass switches within a UPS system:

Static bypass switches for automatic switching from UPS to mains power in the event of a defect within the system.

Manual bypass switch for manual switching from UPS to mains operation, e.g. for maintenance work.

External bypass switch as a direct connection between the power grid and the UPS distributor in order to switch off the system without interrupting the power supply and, for example, to replace it.

The advantages are flexibility, availability, scalability and easy installation.

• flexibility and availability
  The modular design allows the UPS to be easily configured to meet all site-specific UPS performance and redundancy requirements. The individual power modules can function independently of each other and have internal redundancy for maximum availability.

• Scalability
  The modular UPS from EFFEKTA offers multiple scaling options to suit your application. The power scaling of the modular UPS can be achieved by:
  
  - Increasing UPS capacity.
  - Adding a new UPS parallel to the existing system or
  - Adding another UPS and shifting the load to it.
  
  Modular UPSs support capacity scalability by simply adding a new power module to the existing UPS. Using fail-safe paralleling technology, a new UPS can be added to the existing installation without disturbing or interrupting the ongoing operation of the UPS system.

• Simple installation
  EFFKTA UPS systems are easy to install as the flexible modular structure allows site-specific requirements for both bypass and UPS capacity to be adapted.