To be protected against power failures, an uninterruptible power supply on AC or DC side is mandatory. The advantage of AC UPS systems is that this type is buffering all electrical consumers, eg. AC drives, etc. However, an AC UPS system is more expensive than a DC UPS system. If the application allows to buffer only the 24V consumers in case of mains failures, a DC UPS provides a more economical solution.
On one hand no large capacities would be required and the dimensioning can be selected according the needs. Also, the overall efficiency by using a DC UPS system is significantly better because a reconversion of the battery voltage into AC voltage and the repeated transformation in the required 24V DC voltage is not necessary. By using a DC UPS system the energy will be provided at where it is needed, namely, directly at the consumer without any "lossy indirections".
Exhibitor: J.Schneider Elektrotechnik GmbH