NEC EXPRESS800 manual Calculating Load and Determining UPS On-Battery Run Time

Calculating Load and Determining UPS On-Battery Run Time

When you have chosen your configuration, you can use Table 3-4 and Table 3-5 to determine the load on a single power source and how much run time your configuration can expect from your UPS in the event your main AC service is interrupted.

To calculate the load and your on-battery run time, perform the following steps:

1.Determine the total load placed on each power source. The maximum load you can place on a single power source is:

Source	Maximum Load
UPS	3000VA (2250W)
PDU	2880VA

Table 3-4 provides Volt/Amp load values of system components and provides space to include other options.

You can calculate Volt/Amps by multiplying a component’s voltage by its current requirement.

Voltage * Amps = VA

Or if your component’s power requirement is expressed in watts, multiply its wattage rating by 1.4.

Watts * 1.4 = VA

3-8 Planning Your System Rack Configuration