DESCRIPTION OF THE OPERATION OF THE POWER
SUPPLY UNIT
GENERAL INFORMATION
The fundamental role of the power supply unit is to supply connected devices with
electricity from the attached battery modules or an external battery in the event of
irregularities in the mains supply. The time over which electricity is provided by the
unit depends on the capacity of the battery and on the currently connected load. The
power supply unit utilises circuits that detect extreme operating conditions, i.e. an
overload of the converter and a short-circuit at the input. These circuits are active in
the battery operating mode.
When the mains voltage parameters are correct, the power supply unit switches to
mains operation. In this case, prior to reaching the UPS output, the mains voltage is
filtered in the anti-interference circuitry, where additional radio-electric impulses that
degrade the mains power quality are filtered out. If the upper or lower input voltage
limit is exceeded, or if no input voltage is detected, the unit immediately switches to
battery operation. The level of discharge of the battery during battery operation is
given by a sound signal. In the final phase of battery discharge, the signal becomes
continuous, thereby indicating that the UPS will switch off shortly (at full power, this is
approx. 30 seconds, while at lower power levels –a somewhat longer period). Once
the mains voltage is restored, the power supply unit switches to mains operation
and commences the charging process, which is signalled by the diode. When the
battery is fully charged, the diode is continuously on. However, in order to ensure
permanent readiness, the UPS continues to charge the batteries.
In order to increase the life of the batteries, cyclic charging is used in the UPS.
The UPS employs an innovative charging method, which is typically reserved for
high-end power supply units (CBC –COOL BATTERY CHARGING), which utilises
elements of the internal converter. In the mains operating mode, this function
charges the batteries, while in battery operation mode it converts the internal energy
of the battery to an alternating voltage that supplies the protected devices.
If you want to turn the power supply unit on without it being connected to the mains,
you can switch it on in battery mode (cf. “cold start”).