APC PX - Modes of Operation; Load-Disconnect & On-Line Modes

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Modes of OperationModes of Operation

Modes of Operation

The Power Array functions in one of four modes of operation

depending on user commands, the status of the AC mains

(utility) voltage, and the condition of the Symmetra

itself.

The four modes are Load-Disconnect, On-Line, On-Battery,

and Bypass. The PowerView reports the operating mode.

Load-Disconnect Mode

In the load-disconnect mode, incoming mains (utility) power

is present and the system is internally powered, but no output

power is delivered to the load equipment. The Symmetra

enters the load-disconnect mode at the initial power up when

the system enable switch is switched to the on position. When

the system is operating on-line, and the load off command

is entered in the PowerView interface, it returns to the load-

disconnect mode. Figure I-3 illustrates power flow when the

system is operating in the load-disconnect mode.

Fig I-3 Load-Disconnect Operating Mode

On-Line Operating Mode

The on-line operating mode is the normal operating mode.

When the system is in the on-line operating mode, the Power

Array receives AC mains (utility) power and delivers condi-

tioned power to the load equipment. The Power Array main-

tains proper battery charge, regulates the output voltage and

frequency, and protects the load from surges and electrical

noise. Symmetra

will operate in this mode if it has been

commanded to turn the load on, the incoming utility voltage

is present and functioning properly, and there are no prevent-

ing abnormal conditions such as an overload. See figure I-4

for a diagram of the power flow when the system is in the on-

line operating mode.

Fig I-4 On-Line Operating Mode

System Control

and Interface

Communication

Card and

SmartSlots

Powerview User

Interface

Communication Communication

Power Processing Battery Source

Charge

Bypass

Switch

OUT