LEGRAND UPS, User Manual

Page: 13 / 164

UPS user manual
Manuel de l’utilisateur de l’ASI
Utilizzo dell’UPS
OMG38225 REV.B 13
3 GENERAL UPS DESCRIPTION
3.1 TYPOLOGY
The UPS described in this manual is on-line, double conversion; the inverter included in the UPS
always supplies energy to the load, whether mains is available or not (according to the battery
autonomy time).
This configuration guarantees the best service to the User, as it supplies clean power
uninterruptedly, ensuring voltage and frequency stabilization at nominal value. Thanks to the double
conversion, it makes the load completely immune from micro-interruptions and from excessive mains
variations, and prevents damage to critical loads (Computer - Instrumentation - Scientific equipment
etc.).
Output voltage present
The line connected to the UPS output is energized even during mains failure,
therefore in compliance with the prescriptions of IEC EN62040-1, the installer will
have to identify the line or the plugs supplied by the UPS making the User aware of
this fact.
Picture 1 – Block diagram
The UPS uses IGBT technology with a high switching frequency in order to allow a low distortion
of the current re-injected into the supply line, as well as high quality and stability of output voltage.
The components used assure high reliability, very high efficiency and maintenance easiness.
3.2 SYSTEM DESCRIPTION
3.2.1 Rectifier
It converts the three-phase voltage of the AC mains into continuous DC voltage.
It uses a three-phase fully-controlled IGBT bridge with a low harmonic absorption.
The control electronics uses a 32 bit
µ
P of latest generation that allows to reduce the distortion of
the current absorbed by mains (THDi) to less than 3%. This ensures that the rectifier does not
distort the supply mains, with regard to the other loads. It also avoids cable overheating due to the
harmonics circulation.
The rectifier is so sized as to supply the inverter at full load and the battery at the maximum
charging current.