Transformer-Based vs. Transformer-less Power Supplies and Selecting a Power Supply Manufacturer

Deciding between a transformer-based or transformer-less uninterruptible power supply (UPS) is a major decision, especially above 10kVA. Both technologies are important in providing power protection, but there are major differences. Selecting a Power Supply Manufacturer that can both manufacture, as well as provide after-sale guidance on these two technologies, is just as important as deciding on which of these two UPS technologies makes the most sense for the need.

Transformer-Based UPS

Both UPS designs produce a tightly regulated source of interrupted power, but they vary in the way they will generate the voltage by their inverters and their output stages.

Transformer-based UPS was really the only design of online uninterruptible power supplies that were transformer-based prior to 1990. Currently, the design is still available but is generally only available in sizes that range from eight to 800kVA and are most commonly used at large industrial sites.

Transformer-less UPS

Transformer-less UPS is a newer design and most commonly used from 700VA to 120kVA. These are used to reduce the overall physical size and weight, making the UPS a smart idea for smaller installation, such as server rooms and professional offices, where space is usually limited. It is usually quieter than the transformer-based UPS and makes it more compatible with environments where electronic equipment, like computers, may be sensitive to harmonic distortion. A transformer-less UPS uses a staged process of voltage conversion.

Choosing between UPS Types

In many situations, choosing between the two types of UPS is fairly obvious, and is based on power need. They do overlap, however, when it comes to rating. Additionally, initial purchase cost, space limitation, ongoing running costs and harmonic distortion levels also can play into the decision. Both UPS designs can even be operated in parallel to achieve higher levels of availability and flexibility.

Selecting a Power Supply Manufacturer Based on UPS Type

Selecting a power supply manufacturer is just as important as selecting the correct UPS type. A power supply manufacturer may specialize in a particular type of UPS and will have the ability to provide critical assistance on its application, installation, ongoing running costs and ongoing maintenance.