Theory of Operation, Application and Use

TOSHIBA

1.0Product Description

1.1Theory of Operation

An uninterruptible power supply is a system that is installed between the commercial power and the load equipment. It is used during short-term blackouts or brownouts. The UPS provides steady ac output power during these commercial power interruptions. This power is provided for a long enough time so that the load can be shutdown in an orderly fashion. This prevents loss of data and possible damage to both hardware and software.

During normal operation the UPS uses commercial ac power. In addition, it also takes in all of the high voltage spikes and transients caused by switching and faults, and all of the common mode and normal mode noise which is associated with commercial ac power. The UPS converts it all to flat dc power. From this dc power, the UPS charges its batteries and generates its own extremely high quality ac waveform output. The result of this process is maximum power conditioning.

If the ac power supplied to the UPS drops below a specified voltage level, the unit's batteries automatically begin supplying power instead of receiving it. This insures that the loads connected to the UPS continue to receive power with no interruption. When ac input power becomes available again, operation returns to normal. The unit's batteries begin to recharge so they will be ready for the next power interruption.

1.2Application and Use

Toshiba's 1500 and 1500 Plus Series of on-line uninterruptible power supply (UPS) systems provide continuous computer-grade ac power in a compact, high performance, and energy efficient unit. The UPS unit assures safe and reliable operation of critical office equipment. This can range from word processors and personal computers to mini-computers and local area networks. All units feature an audible alarm which sounds if the battery voltage drops below standard during use. This is an additional aid to help in retaining the valuable office data banks. All units allow for computer interfacing and an external battery pack option (see specifications).

1.3Power Backup

When an electrical power failure occurs, the UPS unit's internal maintenance-free batteries automatically supply back-up power to the load without interruption. For example, when used to support a computer, the UPS back-up assures enough additional time to complete the activity and store data. This allows an orderly shutdown after a power failure has occurred.

1.4Power Conditioning

When commercial power is present, the UPS supplies conditioned power to the load while maintaining its batteries in a charged condition. The UPS protects against the normal everyday problems associated with heavy use of raw commercial ac power, including power sags, surges, signal interference, and spikes. This protection keeps power-line problems from reaching the loads where they can cause equipment to operate erratically, hard-disk crashes, or cause damage to hardware and software.

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