Description: *AC voltage: AC 40.0-300.0V or AC 250.0-450.0V (you need to select a meter type in your order) *The measurement range 40-300V without limitation, and can be used in MAINS power, photovoltaic and inverter current *250-450V can only be used for 380V *AC current: AC 0-100.0A, the current resolution is 0.01A. *Frequency: 45.0Hz-65.0Hz *Power factor: 0.00-1.00PF *Electric Power: 0-450000W, the electric power resolution is 0.1W when measuring the electric power between 0-9999.9W, otherwise the electric power resolution is 1W. *Electric Power: 0-99999kwh, the Electric Power Resolution display is 0.01kwh when measuring electric power between 0-999.99kwh, the Electric Power Resolution display is 0.1kWh when measuring electric power between 1000.0-9999.9 KWH and the Electric Power Resolution display is 1kWh when measuring electric power over 9999.9 kWh. 3. Speed: 2 times per second 4. Size: 54 × 80 × 64 5. Installation: Din rail Application Method 1. Connect the measurement voltage to terminal 1 and 2 2. Meter connections with internal current transformer as graph 1. Make the wire go through the hole in the meter and the direction arbitrarily choose. 3. Connections of the meter with external current transformer as graph 2. Make the wire pass through the hole of the meter and connect the two wires of the secondary transformer to terminal 3 and 4. 4. When turned on, the meter displays the measurement parameters. 5. When it is turned on, you can press the button of SAM CK to last 5 seconds, then the electric power will be zero and it will start to accumulate when you release the button. And when power off, the meter can save the electric power value and keep accumulating data when the meter is next turned on. Attention: The meter can only be used to measure 45-65Hz AC urban electricity. Package list: 1* Voltage and current power frequency factor meter counter