OPERATION
EATON
Powerware
®
9170
+
UPS (3–18 kVA) User’s Guide
S
164201393 Rev C
www.powerware.com
80
Off mode turns off the output and most internal circuitry. Within this
mode, Sleep mode turns off all internal circuitry when AC line is not
present and battery voltage drops to a low threshold. If AC input voltage
is not present in Off mode, the user can direct the UPS to enter Sleep
mode by selecting the Battery Protect (BP) feature (see “Removing
Input Power” on page 81). When AC input voltage returns in the Off
mode (caused by a low battery alarm condition), the UPS automatically
recovers and, if the Auto Restart parameter is enabled, switches to
Double Conversion mode. Auto Restart is enabled as a factory-default.
After a discharge and subsequent low-battery shutdown, the UPS
automatically recovers from Sleep mode if the Auto Restart parameter is
enabled.
Figure 54 shows the basic functional elements of the UPS.
Input
(utility)
Power
Input Power (boost)
Converter
Internal DC
Power Bus
DC/AC Power Inverter
Output Relay
Bypass Relay
Capacitor Bank
Battery Charger
Battery
Modules
(parallel)
Line/Battery
Relay
Isolation
Transformer
(optional)
EMI/RFI
Filter
Figure 54. Powerware 9170
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UPS Functional Block Diagram