PR300 Power and Energy Meter

The PR300 power monitor's analog output is a function that converts measured data to DC current (an output signal of 4 to 20 mA DC). Also, the active power when the PR300 is connected to another device (such as a recorder) with the analog output connection is calculated with the following equation.

• Rated power: the rated power of the PR300
• VT ratio (ratio of the voltage transformer): the PR300's initial value is 1 (the setting when not using VT)
• CT ratio (ratio of the current transformer): the PR300's initial value is 1.00 (the setting when not using CT)

1. When a VT is not used, the VT ratio is the initial value of 1.
2. When using the CT, the ratio is 500 A/5A = 100.
3. The PR300's rated power is 2000 W. (See the table below, three-phase three-wire/input (AC), 240 V/5 A rated power)

The active power is calculated using the following equation.
  Active power= 2000 × 1 × 100 = 200,000 =200 kW

Thus, the scaling of the active power in the analog output (4 to 20 mA DC) in this case is 0 to 200 kW .

Analog output scaling settings

You can change the setting range of the scaling on the PR300 with the following parameters.

• Scaling lower limit: Initial value of 50.0 (0.0 to 50.0%)
• Scaling upper limit: Initial value of 100.0 (50.0 to 100.0%)

Note: the settings for the scaling upper and lower limits must be set so that they satisfy the following condition.

  Scaling upper limit − scaling lower limit ≥50
* If this condition is not met, the changed settings will not be applied, and the original

Using the calculated results in the example above, the relationship between the active power scaling settings and the measured input is as follows.

At the initial values (lower limit of 50.0 / upper limit of 100.0)

When the setting is changed (lower limit of 0.0 / upper limit 100.0)