Standby UPS for Small IT Applications

A range of standby UPS to provide basic power protection to IT network peripherals, Internet of Things (IoT) devices and small office and home office computers, CCTV and alarm panels, EPoS terminals and desktop computers. The uninterruptible power supplies are sometimes referred to as off-line UPS as they provide basic filtering when mains is present and battery backup when the mains power supplies via an off-line inverter.

What is a Standby or Off-line Uninterruptible Power Supply?

A standby UPS is an uninterruptible power supply which is classed under IEC EN62040-3 as Voltage and Frequency Dependent (VFD). This means that the UPS output when the mains power supply is tracks the incoming voltage and frequency inside a pre-set threshold window, normally ±10% in terms of voltage. Outside this the inverter, which is normally off (re the term ‘off-line’) is switched on to support the load with battery power.

The standby or off-line UPS is designed for short-duration runtimes and the support of IT network devices, small computers and PCs, Industry v4.0 and Internet of Things (IoT) applications. The UPS size is generally up to 1kVA and the runtime is provided by a valve regulated lead acid (VRLA) lead acid or lithium-ion battery set.

When mains power is present, a standby UPS will provide basic power protection using an EMI/Spike filter to prevent high energy surges from damaging connected loads. There is no mains voltage stabilisation or regulation unless then inverter section switches on.

The output waveform on inverter will typically be a square-wave or step-wave and with a transfer time of 2-4milliseconds or greater. The waveform and transfer time are suitable for more electronic devices and switch mode power supplies (SMPS).

Output connections can be via IEC320, BS-style 3-square pin or Schuko sockets.

Remote monitoring is available via an RS232/USB interface port built-into the UPS.

User Replaceable Batteries

Off-line UPS tend to have user-replaceable batteries and replacement UPS battery kits can be supplied. The old batteries can be returned for recycling under the WEEE/RoHS directives.