In the statistical analysis of manufacturing costs, the consumption of electrical energy is often a critical aspect that producers pay significant attention to. Nowadays, many manufacturing enterprises, when procuring equipment, typically demand integration of a Power Measuring Device for accurate monitoring of electrical energy consumption during the production process. In this article, we will guide you on the usage of Siemens' energy measuring device, PAC4200, for precisely measuring equipment power consumption. PAC4200 is a member of the Siemens SENTRON family, which also includes PAC3200, PAC5200, and others. Its appearance is depicted in the following image:
In the front panel of the device, there are four buttons labeled F1 through F4. F4 serves as the main menu key, F3 as the downward navigation key, F2 as the upward navigation key, and F1 as the exit key. PAC4200 is capable of measuring phase voltage, line voltage, active power, etc. (The operation manual for PAC4200 is available for download at the end of this article).
The back panel of PAC4200 is illustrated in the image below:
IL1 k: Current input for phase L1 (The first letter "I" denotes current, and "k" denotes input).
IL1 I: Current output for phase L1.
IL2 k: Current input for phase L2.
IL2 I: Current output for phase L2.
IL3 k: Current input for phase L3.
IL3 I: Current output for phase L3. (All the above currents are from current transformers).
V1: Voltage input for phase L1.
V2: Voltage input for phase L2.
V3: Voltage input for phase L3.
VN: Voltage neutral point (zero line).
and 12) The two terminals are the working power supply for PAC4200. The device can withstand a voltage of 500V (the wide-voltage type can withstand 600V). Phase line L1 can be connected to terminal 11, and the neutral line N can be connected to terminal 12. Alternatively, it can be connected to a direct current source, with positive connected to terminal 11 and negative to terminal 12.
Reference potential, ground.
Common terminal for digital input.
Digital input channel 1.
Digital input channel 0.
Common terminal for digital output.
Digital output channel 1.
Digital output channel 0.
After understanding the terminal definitions, let's discuss wiring. PAC4200 supports five wiring configurations.
3P4W: Three-phase four-wire system (unbalanced load).
3P3W: Three-phase three-wire system (unbalanced load).
3P4WB: Three-phase four-wire system (balanced load).
3P3WB: Three-phase three-wire system (balanced load).
1P2W: Single-phase two-wire system.
Here, we will use "3P4W Unbalanced Load" as an example to explain the wiring for PAC4200 (equipment such as motors and transformers in the field are considered unbalanced loads). The diagram is shown below:
In the illustration above, X1 terminal is connected to the secondary side of three current transformers (primary side connected to measure phase line L). The induced current flows into the "k" terminal (e.g., IL1 k) and exits from the "I" terminal (e.g., IL1 I), with the "I" terminal reliably grounded. Note: The secondary side of the current transformer must not operate in an open circuit. Reiterating: The secondary side of the current transformer must not operate in an open circuit. Why? Because current transformers operate based on electromagnetic induction principles. When there is current passing through the primary side and the secondary side is in an open circuit, the current on the secondary side becomes zero, and magnetic flux disappears. The entire current on the primary side will turn into excitation current, causing the magnetic core to become oversaturated, rapid increase in iron losses, leading to heating and damage of the transformer. Additionally, due to the higher number of turns on the secondary side, it can induce high voltage, posing a safety risk to personnel. Therefore, the secondary side of the current transformer should avoid open-circuit operation and be reliably grounded.
X2 terminal's V1/V2/V3 are respectively connected to the three-phase lines L1/L2/L3, and Vn is connected to the N line (zero line); L/+ is connected to the phase line, N/- is connected to the zero line.
After wiring is complete, power on, and you will observe PAC4200 displaying values. However, some parameter settings are necessary to ensure measurement accuracy.
First, press the F4 button to enter the main menu, then press the F3 (or F2) button to navigate to the "Settings" menu, and press F4 to enter.
In the "Settings" menu, locate "Basic Parameters," press F4 to enter.
In the "Basic Parameters" menu, locate "Voltage Input," and press F4 to enter.
In the "Voltage Input" wiring configuration, select "3P4W," uncheck the voltage transformer option, choose 400V for voltage input, then press F4 to confirm. This configuration is now saved.
Then, press F1 to go back to the previous menu level, locate "Current Input," and press F4 to enter.
Based on the selected current transformers, modify the values for "Primary Current" and "Secondary Current," then save the settings.
At this point, PAC4200 is ready for normal operation. You can navigate to the main menu to check the measured values such as phase voltage, line voltage, active power, apparent power, and other parameters of interest. PAC4200 actually has many advanced features, such as supporting RS485 communication and Modbus TCP communication. We will cover these in future articles.