American Power Conversion MatrixTM UPS - Manual (Page 3)

1. Introduction
1.1 Overview
The UPS is a high-power enhanced line interactive uninterruptible power source designed to provide clean, reliable AC
power to computer, data handling, and telecommunications loads. Normally, the UPS operates "on-line" and provides
power to the load derived from the input utility source. When operating on-line, the UPS continuously regulates the load
voltage by compensating for voltage fluctuations occurring over a wide range on the utility. A multilevel transformer tap
changing circuit provides this regulation while attaining extremely high levels of on-line efficiency. In response to the
need to adjust the load voltage, the UPS temporarily operates the load from power derived from the battery while an
appropriate transformer tap change is made. In the event of unacceptable line conditions, transfer of load power from the
utility to the inverter occurs synchronously and is virtually seamless under all conditions. The voltage waveshape
delivered during "on-battery" operation is a low distortion sine wave. Resynchronization and retransfer of load power to
the utility is automatic upon recovery of the line voltage to within normal limits.
A complete UPS system consists of three module types. The UPS is comprised of an Electronics Unit
(EU), mounted atop an Isolation Unit (IU). Numerous Battery Packs can be purchased and plugged
together on-site to provide the desired run time. The EU is self-connecting to the IU when mounted and
is secured in place with the turn of an oversized hand screw. The EU contains the UPS’s microprocessor
controls, inverter, battery charger, transfer and tap changing circuits, remote interfaces, and the user
control and display panel. The IU contains the UPS’s isolation transformer, EMI/RFI filtering and surge
suppression circuits, bypass circuit, and the utility and load wiring interfaces. The Battery Packs are
"daisy chained" pack-to-pack, and to the EU, using a heavy duty cable and lockable connector system.
Intelligent communications between Battery Packs and the EU is provided via a flat cable terminated
with modular plugs. Each Battery Pack contains four high capacity batteries and microprocessor
controlled electronics for communications and for battery pack voltage and current monitoring.
1.2 Hot Swappable Modules
The Isolation Unit is capable of autonomous operation and allows service or upgrade of the Electronics Unit without
interruption of power to the load. In addition, a worn Battery Pack can be replaced, or new packs can be added, while
maintaining power to the load. In the event of EU failure, functions controlled by the EU are automatically bypassed and
the IU operates autonomously. For servicing, this bypass mode may be selected manually.
1.3 Emergency Power Off (EPO)
For applications where, for safety reasons, power to all room equipment may be cut off, the UPS provides a remote
Emergency Power Off interface.