UPS Technology Explained

Offline-Standby Technology

The load is normally powered from the utility mains supply with no power conversion. Its operating principle is sequential (on mains/on battery). If there is a power failure, or a drop or increase in voltage, the UPS takes power from its battery to provide a stabilized power source. Off-line technology is not suitable for use if there are frequent disturbances (industrial or rural environments

Advantages

• Low Cost
• Silent operation when in standby
• Efficient

Disadvantages

• Minimal power protection - only protects against a small percentage of problems
• Poor output voltage regulation - fluctuations such as sags and surges will be passed straight to the load
• Break transfer to battery mode
• No failsafe - UPS will drop the load if there is a high start-up current, overload or inverter failure

Line-Interactive Technology

It operates in the same way as an Off-line UPS. The UPS uses microprocessor control, monitoring the quality of the mains supply and responding to changes.
A booster, (voltage compensation circuit), is activated in the event of an extended dip in voltage.
Line interactive technology, as with off-line, is not suitable

Advantages

• Lower cost than online
• Gives better protection than offline
• Silent operation when in standby
• Efficient

Disadvantages

• Fluctuations, such as spikes, can still be passed straight to the load
• Break on transfer to battery mode
• No failsafe - UPS will drop the load if there is a high start-up current, overload or inverter failure

Online Double Conversion Technology

On-line UPS have superior voltage regulation and conditioning features than off-line and line interactive designs. They are generally considered essential for IT servers that house critical applications, for sensitive electronic equipment where mains power might be subject to fluctuation or for use with a diesel generator.

In on-line double conversion technology, incoming mains power is converted into DC power by the rectifier / charger. The DC is converted back into clean AC by the inverter and fed to the load, which is fully supported under normal conditions. When a mains failure occurs, the inverter draws DC power from the battery instead of the rectifier. As a result, on-line UPS provide a no-break transfer to battery power on mains failure.

Advantages

• Continuous & total power conditioning
• Failsafe/overload protection with static bypass facility
• No break on mains failure
• Wide input voltage tolerance
• Recommended with Generator sets

Disadvantages

• More expensive than other types of UPS technology
  

UPS & Generators

Due to the nature of the supply from a Generator we recommend utilizing Online Double Conversion Technology UPS.
Online UPS have improved input frequency and voltage tolerance over non-online technology, therefore preventing frequent switching to battery power which maximizes battery life and UPS reliability.
Because Online Double Conversion Technology completely regenerates the AC output it will be completely free from interference such as spikes and voltage variations which may adversely affect IT or other types of sensitive equipment.
Non-online UPS will often work, although intermittently, with a Generator supply but will ultimately fail. Usually the UPS failure happens under load or when the Generator is providing the main supply. A Generator backed supply is often a critical one and necessitates the highest form of protection, Online Double Conversion Technology provides this protection.

For further information please do not hesitate to call us on 0845 833 0333 and we will be pleased to answer any questions.