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page 34 / 75 0MNA080A55-GB REV 01
INVERTER
This is the output stage, the function of which is to convert the direct voltage from the RECTIFIER or from the
BATTERY into stabilized sinusoidal alternating voltage. The inverter output is isolated from the input and from the
batteries by a galvanic isolation transformer. The transformer has a screen between the primary and the earthed
secondary. The inverter is always working, since the load connected to the UPS output is always powered by the
INVERTER (in NORMAL OPERATION)
STATIC SWITCH
This device allows the synchronized switch, automatic or manual, and in zero time, of the power supply to the load
from a protected line (inverter output) to an unprotected line (by-pass line) or vice versa.
The SENTRY MPS-HP is provided with a device to prevent the backfeed of voltage to the input line after an
internal fault, known as “
BACKFEED PROTECTION”.
MANUAL MAINTENANCE BY-PASS (SWMB )
This is a maintenance disconnector. The UPS can be excluded by closing SWMB and opening the other
disconnectors SWIN, SWBY, SWOUT while keeping the load on the output powered. This operation is necessary
when maintenance operations must be carried out inside the equipment without interrupting the power supply to the
load.
The disconnector is sized for the rated power of the UPS.