8
6
3
5
11
7
9
1
10
8
2
4
Functional Elements
1
Input (mains) power
2
Input power (boost) converter
3
Internal DC power bus
4
DC/AC power inverter
5
Output relay
6
Bypass relay
7
Capacitor bank
8
Battery charger
9
Battery modules (parallel)
10 Line/battery relay
11
Isolation transformer (optional)
202 Functional Features
The Axxium Pro UPS operates in several different modes. Normally it operates under internal control, called
Auto Mode, to automatically protect loads connected to it. It also functions under operator control to enable
manual override should servicing or testing be required.
Figure 2 is an illustration of the operating modes. In Auto
Mode, the UPS automatically switches between modes
depending on line and load conditions.
Double Conversion mode produces output power from
the internal DC bus. The input AC power is rectified and
boosted to supply this DC bus. The UPS switches
automatically to and from Battery mode with no
interruption (0 ms transfer time) as AC input power drops
and returns. Batteries are charged in this mode.
Battery mode produces power from the batteries to supply the internal DC bus.
Internal Bypass (Bypass) mode shunts power flow around the DC/AC internal circuitry to keep the output
powered with no line conditioning. Electromagnetic interference (EMI) and surge circuitry still protect the loads
from voltage spikes and noise.
The High Efficiency mode is a user-programmable automatic mode of operation. This mode allows power to
flow through the internal UPS bypass path for as long as AC input stays within the user setpoints. If the input
voltage or frequency deviates beyond the user setpoints, the Axxium Pro system transfers to the Double
Conversion mode of operation. Complete loss of input voltage causes the UPS to transfer to Battery mode.
While in High Efficiency mode, the Axxium Pro system provides passive EMI filtering in the power path.
Figure 3. Axxium Pro UPS Functional Block Diagram
Figure 2. Axxium Pro UPS Operating Modes
(under Auto Mode control)
Double Conversion
(Line Conditioning)
Battery
Off
Internal
Bypass