Online UPS

An online UPS is a double conversion uninterruptible power supply that converts mains voltage first to direct current and then back to alternating current with an inverter, supplying the load continuously through the inverter. Because there is no transfer time during an outage and the output voltage and frequency stay independent of mains disturbances, it is used for servers, data centers, medical devices and industrial automation loads. This category includes Siel, ABB and Schneider Electric models; besides tower and rack-tower type devices of 1 kVA, 3 kVA, 6 kVA and 10 kVA, there are systems with 3ph/1ph and 3ph/3ph input-output and power ratings such as 20 kVA, 60 kVA and 200 kVA. Choose the online UPS by the apparent and active power of the load (kVA and kW), input-output phase configuration (1ph/1ph, 3ph/1ph or 3ph/3ph), the battery runtime required, whether it comes with or without batteries, and tower or rack mounting. For models without batteries, the battery bank is supplied separately. A line interactive UPS switches to the battery with a short transfer time during an outage; it therefore does not replace an online UPS for loads sensitive to transfer time.

Products

How to choose Online UPS

An online UPS is a double conversion uninterruptible power supply that converts mains voltage first to direct current and then back to alternating current with an inverter, supplying the load continuously through the inverter. Because there is no transfer time during an outage and the output voltage and frequency stay independent of mains disturbances, it is used for servers, data centers, medical devices and industrial automation loads.

  • Determine whether backup power bridging (UPS) or voltage regulation is required.
  • Calculate kVA rating, phase configuration and backup runtime from the critical load list.
  • Verify battery bank, bypass topology and monitoring interface requirements.

Frequently asked questions

What is Online UPS and where is it used?

An online UPS is a double conversion uninterruptible power supply that converts mains voltage first to direct current and then back to alternating current with an inverter, supplying the load continuously through the inverter. Because there is no transfer time during an outage and the output voltage and frequency stay independent of mains disturbances, it is used for servers, data centers, medical devices and industrial automation loads.

What should I compare when choosing Online UPS?

Choose the online UPS by the apparent and active power of the load (kVA and kW), input-output phase configuration (1ph/1ph, 3ph/1ph or 3ph/3ph), the battery runtime required, whether it comes with or without batteries, and tower or rack mounting.

Where can I find technical details for Online UPS products?

A line interactive UPS switches to the battery with a short transfer time during an outage; it therefore does not replace an online UPS for loads sensitive to transfer time.

Online UPS Selection Guide