When Utility Is Abnormal Or Absent; Overload Condition - Ablerex 1 kVA User Manual

5.3. When Utility is Abnormal or Absent

The operating mode of the UPS under abnormal utility conditions is illustrated
as follows.
RECTIFIER
AC/DC CONVERTER
DC/DC CONVERTER
UTILITY
CHARGER BATTERY
1. When the utility is abnormal the UPS will direct the battery energy automatically
to the Inverter without delay and turn off the charger and AC/DC converter. The
inverter reverts DC to AC to supply energy to the output load connected without
interruption. The LED will shine.
2. When the utility returns to normal the UPS will turn on the AC/DC converter,
turn off the DC/DC converter, and switch the charger to charging mode. This is
the same operating mode as in Figure 5.2.
3. During a utility outage the UPS will work as illustrated in Figure 5.3. When the
batteries are low the buzzer will beep continuously until the batteries are
completely cut off. The low-battery protection of the UPS will cut off the battery
supply at a preset threshold to avoid over-draining the batteries.
4. The UPS will restart automatically when the utility is available, with the same
status as in Figure 5.2.
STATIC SWITCH
INVERTER
( SSM)
18
5.4.

Overload Condition

The operating mode of the UPS when overloading occurs is illustrated as
follows.
O/P
OUTPUT
UTILITY
CHARGER
1. Generally, modern electronics and IT equipment generate an inrush current
when switching on. The amount of inrush current varies from equipment to
equipment, sometimes as high as six times rated capacity, other times negligible.
To prevent severe damage to its inverter caused by the inrush produced by the
loads, the UPS is equipped with an electronic overload-protection feature as
standard. If the UPS is loaded over 150% of capacity it will switch into bypass
mode until the load is less than 105%. Then the UPS will switch back to Inverter
mode automatically.
2. The UPS Bypass loop is also equipped with overload protection. Its overload
capacity is illustrated by the graphs and table below.
RECTIFIER
AC/DC CONVERTER
INVERTER
DC/DC CONVERTER
BATTERY
19
STATIC SWITCH
O/P
(SSM)
OUTPUT