Transformer-less UPS systems differ from transformer-based UPS systems in terms of how they operate and handle the incoming power source. The main reason transformer-less UPS units should not be fed from the same source as transformer-based UPS systems is due to potential differences in their electrical characteristics and design.
- Different characteristics to function: Transformer-less UPS systems typically operate with a different internal voltage and frequency range reference to the ground than transformer-based UPS systems. When connected to the same power source, there could be issues with mismatched functions, leading to improper functioning or even damage to the UPS equipment.
- Isolation and Grounding: Transformer-based UPS units provide electrical isolation between the input and output, which means that there is no direct electrical connection between the two sides. Transformer-less UPS systems, on the other hand, do not have this isolation and often have a common ground. Mixing these two types of UPS systems on the same source can create grounding issues and result in potential safety hazards.
- Harmonics and Distortions: Transformer-less UPS systems usually generate different or less harmonics and electrical distortions compared to transformer-based units. Feeding them from the same power source can amplify the induced harmonics from Transformer based to transformer-less and causing misfunction or damaging to the unit.
- Fault Currents and Protection Coordination: In the event of a fault or electrical overload, transformer-less UPS systems may have different fault current levels and protection coordination characteristics compared to transformer-based systems. This can lead to difficulties in coordinating protective devices, increasing the risk of failure or malfunctions.
To ensure safe and reliable operation, it is generally recommended to keep transformer-less UPS systems and transformer-based UPS systems on separate power sources. If both types of UPS units are necessary in a facility, they should be installed with proper isolation and consideration of their electrical characteristics to prevent any compatibility issues. Consulting with a qualified electrical engineer or UPS system expert can help ensure the correct setup and safe operation of the UPS systems in such scenarios.
