Question

How does an online UPS differ from a standby UPS?

Answer 1

An online UPS and a standby UPS both provide backup power, but they operate differently to protect your devices from power interruptions. Here's a simple breakdown of the differences:

Online UPS:

1. Continuous Power Supply:
   

   - In an online UPS, the connected devices are always powered by the UPS's battery through its inverter. Even when the main power supply is working normally, the UPS constantly provides power.
   

1. No Switching Time:
   

   - Since the UPS is always supplying power, there is no switching delay when the power goes out. The devices receive power instantly from the battery or inverter without interruption.

1. Best Protection:
   

   - This type provides the best protection from all types of power problems, like power surges, sags, and interruptions, because it continuously filters and supplies clean power.

1. More Expensive:
   

   - Online UPS units are typically more expensive and less energy-efficient than standby UPS systems because they are always operating in battery mode.

Standby UPS:

1. Backup Power Only:
   

   - A standby UPS only switches on when the main power supply fails. When the power is normal, the connected devices run directly off the utility power.

1. Switching Delay:
   

   - When a power failure occurs, the UPS has to switch to the battery power, which can take a few milliseconds. This slight delay might cause problems for sensitive equipment.

1. Basic Protection:
   

   - It offers basic protection against power outages, but it does not filter or condition the incoming power as well as an online UPS does. So, it might not protect against power surges or voltage fluctuations as effectively.

1. Cheaper Option:
   

   - Standby UPS units are cheaper and more energy-efficient compared to online UPS units because they only use the battery when necessary.

Summary:

1. Online UPS: Continuous protection, no switching time, better for sensitive equipment, more expensive.
   

1. Standby UPS: Powers equipment directly from the grid until a power failure occurs, has a slight delay, cheaper, good for basic protection.
   

In general, if you need high protection for sensitive equipment (like servers or medical devices), an online UPS is the way to go. For less critical equipment like personal computers, a standby UPS might be enough.