Filter
Top Products
Eaton 9170
+
UPS (3–18 kVA) User's Guide S 164201393 Rev E www.eaton.com/powerquality
77
Chapter 8 Operation
The Eaton 9170+ UPS operates in several different modes. Normally it
operates under internal control (Auto mode) to automatically protect
loads connected to it. An operator can enable manual override should
servicing or testing be required.
Figure 52 shows the operating modes. In Auto mode, the UPS
automatically switches between modes depending on line and load
conditions.
Double Conversion
(line conditioning)
Internal Bypass
Battery Off
Figure 52. UPS Operating Modes Under Auto Mode Control
Double Conversion mode produces output power from the internal DC
bus. The AC input 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.
High Efficiency (H.E.) mode is a user-programmable automatic mode
that allows power to flow through the internal UPS bypass path for as
long as AC input stays within the user-defined set points. If the input
voltage or frequency deviates beyond these set points, the UPS
transfers to Double Conversion mode. Complete loss of input voltage
causes the UPS to transfer to Battery mode. While in H.E. mode, the
UPS provides passive EMI filtering in the power path.