A brownout, sometimes also called a ‘sag’, is a "dip" in the voltage level of the electrical line. When a brownout occurs, the voltage drops from its normal level to a lower voltage and then returns. UPS systems can handle a reduction in the nominal voltage due to it’s input voltage window. If the voltage falls outside this window the battery can take over without any disturbance to the load.
Brownouts are extremely common and can sometimes be detected by lights flickering or dimming; often during heavy load periods or severe weather conditions. As demands power increase, so does the risk of brownouts. Brownouts can wreak havoc with IT loads. In many ways, they are worse than a blackout. In a blackout, the power just goes off, but with a brownout the device continues to get power but at a reduced level, and some devices will malfunction rather than failing totally.
Consider a central back-up system to eliminate expensive re-cabling. Wise to involve a company specialising in power conditioning.
Access the level of power protection required. Some installations may demand that every item is supported by UPS, others may only require UPS for a central server and one or two workstations.
Type of Client/Application
Emergency services, financial institutions, Industrial etc. This can have an impact on the system specification.
Inner city areas may be more susceptible to power fluctuations. Rural areas may be affected by weather conditions on power lines. More remote areas may be located at the very end of the power line.
Converts AC voltage to DC voltage, recharges the batteries and maintains float voltage, handles overloads and buffers surges, can accept wide input voltage fluctuations.
Converts DC voltage to AC voltage, regulates and filters AC voltage.
Automatically connects load to mains supply if overload or fault occurs.
Provides emergency power source when mains supply fails.
Capability for total isolation for UPS maintenance, with no disturbance to the load. Greatly reduced cost and size when compared to other systems using ‘Key interlocking.’ Totally safe and user friendly, simple switching sequence, no risk of back-feeding UPS. Use of electrical interlocking ensures ‘no-break’ transfer without complex & expensive key interlock arrangement.
No need for additional Maintenance switches or key exchange boxes (cost savings)
Standard system using top quality switchgear, which is readily available (prompt delivery)
Can easily be customised to incorporate larger terminals for oversized cables.
Can be built to include full MCB/MCCB protection or just isolation depending on site requirements.
Unit can also incorporate shunt trip facilities for ‘emergency power off’ (EPO) on input and by-pass switches.
Can be installed outside normal hours, by a competent electrician, to enable UPS to be installed during normal hours without a further shutdown.
Capability for ‘ two input’ systems giving greater flexibility and security for the critical load.
Local MCB/MCCB allow downsizing of cables locally without extra protection devices.
Traditional technology, typically available from 10 kVA, suitable for industrial applications, galvanic isolation with inverter output transformer, typically standard technology from 100 kVA upwards.
Typical technology from the smallest ratings up to 120 kVA, more compact footprints, lower weights, more suited to IT applications and environments, high efficiency across the load range, generally more cost effective.