American Power Conversion 250 A manual Fuel monitoring/runtime calculation

How the InfraStruXure Power Generation System Operates

Fuel monitoring/runtime calculation

Fuel monitoring is a unique feature of the InfraStruXure Power Generation System. Fuel level is monitored at the generator (if purchased through APC) and load is measured at the ATS. These measurements are used to calculate runtime, as explained in the following paragraph:

Fuel is monitored by a level sensor in the generator fuel tank (calibrated to the bottom of the tank) that changes readings every -inch of fuel-level change. From these fixed-level points, the ATS counts the number of gallons of fuel used (based on load over time) and subtracts this amount from the fixed-level fuel amount to provide an accurate estimate of fuel level. Runtime is then calculated based on the fuel-usage rate at the current load and the remaining fuel in the tank. Once a new fuel- level point is reached, the value of the calculated fuel used is reset and the computation begins again.

The Fuel Level and Runtime Estimate are displayed on the Generator Status screen on the ATS display interface. In addition, the following Fuel Alarm Limits are displayed in the Alarms menu. Corresponding values can be set for these limits:

Percent Fill: If the amount of fuel as a percentage falls below this value, an alarm condition exists.

Runtime: If the estimated runtime falls below this value, an alarm condition exists.

InfraStruXure Power Generation System 9