Eaton Electrical ASY0674, ASY0673, ASY0529, ASY0567 manual Chapter Operation

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.

Eaton 9170+ UPS (3–18 kVA) User's Guide S 164201393 Rev E www.eaton.com/powerquality 77