<< Click to Display Table of Contents >> Manual > Monitoring system construction guide > Construction of major functions > Demand monitoring > Demand monitoring overview > What is demand power?

What is demand power?

Demand power refers to the average power usage (kW) for 30 minutes during a demand period (30-minute intervals from 0 minutes to 30 minutes and from 30 minutes to 60 minutes of every hour). Increases and decreases in demand power affect the "contract power" applied when calculating electricity charges by electric power companies (in other words, it affects increases and decreases in electricity charges).

 

Demand power can be calculated from the amount of power used (kWh), and the demand power (kW) is calculated by doubling the amount of power used (kWh) for 30 minutes. For example, if a 300kW load is used continuously for 30 minutes, the amount of power used for 30 minutes will be "150" kWh, but the demand power can be calculated by doubling this value to "300" kW.

 

Generally, when the amount of power usage is input into the system, it is input as a pulse counter measurement value (e.g., 1 pulse = 1 kWh) by downstream devices such as PLC or a metering counter module, and is expressed as a ring counter value (e.g., 0 to 99999) on the PLC device. The demand monitoring function of FA-Panel reads the ring counter value of the amount of power usage that is the subject of demand monitoring from the downstream device via a tag, and obtains the amount of power usage by monitoring the increment of the counter value over time, and calculates the demand power from that value.