15
ENGLISH
MASTERYS
BC 60-80 kVA - Ref.: IOMMASBCXX06-EN 06
ENGLISH
3. MODES OF OPERATION
3.1. ON LINE OPERATION
A special feature of the MASTERYS BC series is the ON LINE double conversion feature in conjunction with low distortion mains
power absorption. With ON LINE mode the UPS is able to supply a voltage that is fully stabilised in frequency and amplitude,
regardless of any interference in the mains power supply within the most stringent classification of UPS regulations.
ON LINE operation provides three operating modes according to mains and load conditions:
• Normal mode
This is the most frequent operating condition: the energy is drawn from the primary mains power supply and is converted and used
by the inverter to generate the output voltage to power the loads connected.
The inverter is constantly synchronised in frequency with the auxiliary mains to enable load transfer (due to an overload or inverter
shutdown) without any break in the power supply to the load.
The battery charger supplies the energy required to maintain or recharge the battery.
• Bypass mode
In the event of inverter failure the load is automatically transferred onto the auxiliary mains without any interruption in the power
supply. This procedure may occur in the following situations:
- in the event of a temporary overload the inverter continues to power the load. If the condition persists the UPS output is switched
on to the auxiliary mains via the automatic bypass. Normal operation, which is from the inverter, returns automatically a few seconds
after the overload disappears.
- when the voltage generated by the inverter goes outside the limits due to a major overload or fault on the inverter.
- when the internal temperature exceeds the maximum value allowed.
• Battery mode
In the event of a mains failure (micro interruptions or extended power cuts), the UPS continues to power the load using the energy
stored in the battery. The Expert Battery System keeps the user constantly informed on battery status and back-up time available.
3.2. OPERATION IN HIGH EFFICIENCY MODE
The UPS allows the selection of a programmable ‘economy’ operating mode that can increase overall efficiency by up to 98% for
energy saving purposes. With this mode of operation, specific daily or weekly time intervals can be selected and programmed to
power the applications directly from the auxiliary mains. If the power supply fails the UPS will automatically switch onto the inverter
and continue to supply power to the load by drawing energy from the battery.
This mode does not provide perfect stability in frequency and voltage like the ON LINE mode. Thus the use of this mode should be
carefully evaluated according to the level of protection required by the application.
The Eco Mode operation provides very high efficiency, since the application is powered directly from the auxiliary mains via the
automatic bypass in normal operating conditions.
3.3. OPERATION WITH MANUAL MAINTENANCE BYPASS
If the maintenance bypass is activated using the appropriate procedure the load is powered directly from the maintenance bypass,
while the UPS is separated from the power supply and can be switched off.
This operating mode can be selected for maintenance to be carried out on the system so that the necessary actions can be perfor-
med by service personnel without having to disconnect the power supply to the load.
