American Power Conversion SYMINIF-PD, SYMSTRF-PD On-Battery Operating Mode, Bypass Operating Mode

On-Battery Operating Mode

When in the on-battery mode, the Power Array draws DC power from the battery source, converts it to conditioned AC power that is then delivered to the load equipment. SymmetraTM typically enters this mode in the event of a utility power failure. It will also operate in the on-battery mode during a user initiated battery self test.

On-battery operation is limited in duration and is dependent upon the number of battery modules, their state of charge, and the size of the load. SymmetraTM will remain in the on- battery state until either the incoming utility power is restored, or the batteries are depleted. See figure I-5 for a diagram of the power flow when the system is in the on-battery mode.

Fig I-5On-Battery Operating Mode

Bypass Operating Mode

When the SymmetraTM is in the bypass operating mode, the system is bypassed, and utility power is delivered directly to the load. SymmetraTM is equipped with an automatic bypass function to allow the system to automatically go into bypass mode, and a manual maintenance bypass switch to allow a user to manually bypass the system. Either can be used to place the Power Array into bypass operating mode.

The SymmetraTM will automatically transfer to the bypass operating mode when AC utility power is present, but the load cannot be powered by the inverter. Events which may cause this include overloads, or failed non-redundant power mod- ules. The SymmetraTM will automatically return to the on-line mode when the triggering event clears. Figure I-6 illustrates the power flow when the system is in the bypass mode.

Fig I-6Bypass Operating Mode

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