TOSHIBA
1.1 Theory of Operation
An Uninterruptible Power System (UPS) is a system that is installed between the commercial
power and the load equipment. The UPS provides steady AC output power during commercial
power fluctuations and interruptions.
During normal operation the UPS receives commercial AC power and removes any high
voltage spikes and transients caused by switching or faults on the main utility. The result of this
process is maximum power conditioning and regulation of the power applied to the load.
If the AC power supplied to the UPS drops below a specified voltage level, the batteries of the
UPS are automatically switched on and will supply power to the load. This insures that the loads
connected to the UPS continue to receive power with no interruption. This power is provided for a
period long enough to ensure that the load can be shut down in an orderly fashion. This prevents
loss of data and possible damage to the hardware or software.
When AC input power becomes available again, normal system operation resumes and the
UPS battery-charge cycle resumes.
1.2 Application and use
The TOSHIBA 4200FA Uninterruptible Power Systems (UPS) provide continuous computer grade
AC power in a compact and efficient high-performance unit. The UPS assures safe, reliable
operation of critical office equipment, ranging from personal computers to mini-computers to local
area networks (LAN). All units feature an audible alarm that sounds if the battery voltage drops
below standard during use. This is an additional aid to help in retaining the valuable office data
banks, and all units allow for computer interfacing.
1.3 Power Backup
During an electrical power failure the batteries of the UPS unit supply DC power to the inverter that
supports the load equipment automatically, without interruption. For example, when used to
support a computer, a UPS backup assures additional time to complete your activity and store data
after a power failure occurs.
1.4 Power Conditioning
While commercial power is present, the UPS supplies conditioned power to the load while
maintaining the batteries in a charged condition. The UPS protects the connected load against the
normal everyday problems associated with heavy use of raw commercial power, including power
sags, surges, signal interference, and spikes. This protection keeps power-line problems from
reaching your load where it can cause equipment to operate erratically, or damage software or
hardware.
8 4200FA User’s Manual