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4.0 Principles of operation
4.2 Load transfer switch
The load transfer switch is actually an
4.3 Battery charger
In the event of utility failure, the PowerCell supplies power to your equipment derived from energy taken from a battery. The PowerCell’s battery charger converts the alternating current (AC) supplied by the utility to a direct current (DC) which is compatible with the battery. The charger maintains the battery at a constant voltage to ensure that the battery will have the capacity to support your load as often as possible. This charging method, known as “float” charging, provides maximum battery service life and minimal internal heating. The battery charger operates whenever the PowerCell is plugged in, whether or not the UPS is turned on.
4.4 Battery
The PowerCell’s battery is an energy source much like the battery in an automo- bile. Also, like most automobile batteries, the PowerCell’s battery is a modern maintenance free
4.5 Inverter
The PowerCell must convert the battery’s energy into a form that your computer equipment can rely upon during a utility failure. This is the job of the UPS’s inverter. The PowerCell converts the battery’s DC toAC using solid state devices (transistors), controlled using a technique known technically as “pulse width modulation”. This technique is highly efficient which means that little battery power is wasted in the conversion process. Hence, your equipment can run for long periods from the PowerCell before the battery’s capacity is spent.
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