Category: Industrial control technology

I. Application Scenario and Function Analysis

The main functions of chemical metering pumps include:

• Precise Flow Control: Achieve quantitative delivery of chemicals by adjusting the pump’s rotational speed.
• Start/Stop Control: Ensure smooth start and stop of the pump to avoid pressure surges.
• Pressure/Flow Feedback Regulation: Adjust the pump speed in real-time based on sensor feedback.
• Fault Protection: Automatic shutdown in case of overload, over-temperature, under-load, etc.
• Remote Monitoring and Operation: Realize automated operation through fieldbus or external controllers.

The VACON 100 HVAC inverter is suitable for these requirements. It supports multiple control methods (digital input, analog input, fieldbus), has built-in HVAC application macros, fault diagnosis functions, and rich parameter settings, which can well meet the control requirements of chemical metering pumps.

Specific Functional Positions in the Application

• Main Drive Motor: Drives the metering pump and controls its rotational speed to regulate the flow rate.
• Auxiliary Motor (if any): Used for the cooling system or stirring device (depending on the process requirements).
  The following design focuses on a single main drive motor. If an auxiliary motor is required, it can be expanded according to similar logic.

II. Hardware Selection

1. Motor Selection
   • Type: Three-phase asynchronous motor (commonly used in metering pumps). The power is selected according to the pump’s load requirements, such as 0.75 kW or 1.5 kW.
   • Voltage: Match the inverter’s power supply voltage, such as 380 – 480 V (common industrial standard).
   • Protection Level: The chemical environment may be corrosive, so it is recommended to choose a motor with an IP55 or higher protection level.
2. Inverter Selection
   • Model: VACON 100 HVAC. The rated current should be greater than the motor’s full-load current (e.g., for a 1.5 kW motor with a current of about 3.5 A, choose a model with a rated current ≥ 4 A).
   • Power Supply: 380 – 480 V three-phase AC (refer to Section 7.1.2 of the installation manual).
3. External Devices
   • PLC: Select Siemens S7 – 1200 (such as 1214C) for logic control and data processing.
   • Touch Screen: Siemens HMI TP700 Comfort for parameter setting and running status display.
   • Sensors:
     • Flow Sensor: Outputs a 4 – 20 mA analog signal for flow feedback.
     • Pressure Sensor: Outputs a 4 – 20 mA analog signal for pressure monitoring.
   • Relay: 24 V DC for controlling the start/stop signals.

III. Wiring Scheme

Refer to Section 7.2.1 of the installation manual and relevant sections of the application manual for information on the control terminals of the VACON 100 HVAC inverter. The following is the wiring design for the chemical metering pump:

1. Power and Motor Wiring
   • Power Input: Connect to the L1, L2, L3 terminals of the inverter (three-phase 380 V).
   • Motor Output: Connect to the U, V, W terminals of the inverter and then to the three-phase motor.
   • Grounding: Connect the PE terminal of the inverter to the grounding terminal of the motor to ensure grounding complies with the EN61800 – 5 – 1 standard (refer to Section 1.3 of the installation manual).
2. Control Terminal Wiring
   Refer to the technical information of the standard I/O board in Section 7.2.1 of the installation manual:

Wiring Diagram (Text Description)

• Power Input:
  • L1 —- [Inverter L1]
  • L2 —- [Inverter L2]
  • L3 —- [Inverter L3]
• Motor Output:
  • [Inverter U] —- [Motor U]
  • [Inverter V] —- [Motor V]
  • [Inverter W] —- [Motor W]
• Grounding:
  • [Inverter PE] —- [Motor PE] —- [Grounding Wire]
• Control Signals:
  • [PLC DO1] —- [DI1] (Start)
  • [PLC DO2] —- [DI2] (Stop)
  • [Emergency Stop Button] —- [DI3]
  • [Flow Sensor +] —- [AI1+]
  • [Flow Sensor -] —- [AI1-]
  • [Pressure Sensor +] —- [AI2+]
  • [Pressure Sensor -] —- [AI2-]
  • [AO1+] —- [PLC AI1] (Frequency Feedback)
  • [AO1-] —- [GND]
  • [A] —- [PLC RS485 A]
  • [B] —- [PLC RS485 B]

IV. Parameter Setting

The following parameter settings are based on the application manual and the requirements of the chemical metering pump. Use the start-up wizard and HVAC application macro of the VACON 100 for configuration.

1. Start-up Wizard Settings (Refer to Page 4 of the Application Manual)
   • Language: Select Chinese.
   • Time: Set the current time (e.g., 14:30:00).
   • Date: Set the current date (e.g., 15.10.2023).
   • Application Macro: Select the HVAC application macro.
2. Key Parameter Settings

3. PID Control Settings (Flow Regulation)
   • P3.9.1: Enable PID Control = 1
   • P3.9.2: Setpoint Source = 0 (Fixed value, input from the touch screen)
   • P3.9.3: Feedback Value Source = AI1 (Flow Sensor)
   • P3.9.4: Proportional Gain = 2.0 (Adjust according to actual debugging)
   • P3.9.5: Integral Time = 1.0 s (Adjust according to actual debugging)

V. Control System Design

1. System Architecture
   • PLC: Responsible for logic control, sensor signal processing, and communication with the inverter.
   • Touch Screen: Display running status (rotational speed, flow rate, pressure) and set the target flow rate.
   • Inverter: Execute motor rotational speed control, receive PLC instructions, and sensor feedback.
   • Sensors: Provide real-time flow rate and pressure data.
2. Control Logic
   • Start/Stop:
     • The PLC controls the inverter’s start/stop through DI1/DI2.
     • The emergency stop button triggers DI3, and the inverter stops immediately.
   • Flow Regulation:
     • The touch screen inputs the target flow rate value, and the PLC transmits it to the inverter via RS485.
     • The inverter adjusts the motor rotational speed through PID regulation based on the feedback from AI1 (flow sensor).
   • Pressure Monitoring:
     • AI2 (pressure sensor) monitors the pipeline pressure. If it exceeds the set range (e.g., > 5 bar), the PLC issues a stop command.
   • Fault Handling:
     • When the inverter detects a fault (e.g., overcurrent, fault code 1), it notifies the PLC via RS485, and the touch screen displays the fault information.

Control Schematic Diagram (Text Description)

• [Touch Screen] —- [RS485] —- [PLC]
  • | |
  • | |—- [DO1] —- [DI1] (Start)
  • | |—- [DO2] —- [DI2] (Stop)
  • | |—- [AI1] —- [AO1] (Frequency Feedback)
  • | |—- [RS485] —- [Inverter A/B]
• [Flow Sensor] —- [AI1+/-]
• [Pressure Sensor] —- [AI2+/-]
• [Emergency Stop Button] —- [DI3]
• [Inverter U/V/W] —- [Motor]

VI. Implementation Steps

1. Installation and Wiring:
   • Connect the power supply, motor, and control signals according to the wiring scheme.
   • Ensure reliable grounding to avoid electromagnetic interference.
2. Parameter Configuration:
   • Initialize using the start-up wizard on the inverter panel.
   • Input the above parameters and save the settings.
3. PLC and Touch Screen Programming:
   • Write the start/stop logic and PID control program for the PLC.
   • Design the touch screen interface, including flow rate setting, running status, and fault alarms.
4. Debugging:
   • Manually test the start/stop functions.
   • Adjust the PID parameters to ensure stable flow rate.
   • Simulate faults to verify the protection functions.
5. Operation and Optimization:
   • After long-term operation, fine-tune the parameters according to the actual working conditions.

VII. Precautions

• Safety: Do not touch the internal circuits of the inverter after it is powered on (refer to Section 1.2 of the installation manual).
• EMC: The chemical environment may have interference, so adjust the EMC jumpers (refer to Section 6.3 of the installation manual).
• Support: If you encounter any problems, you can contact us.

I. Overall Concept

1. Application Points and Functions
   In a desiccant packaging machine, there are often multiple drive motors, such as a feeding motor, a sealing motor, a blower/fan motor, a conveyor motor, and so on. If you are focusing on the “desiccant-blowing” or “air-blowing” process, you can apply the HLP-C100 inverter in the following situations:
   • Blower/Fan Motor: By using the inverter to control air volume or blowing speed, you can flexibly adjust airflow according to packaging speed or desiccant characteristics.
   • Conveying/Feeding Motor (if necessary): You can achieve more precise control of the speed at which desiccant moves, preventing blockage or spillage.
   • Other Auxiliary Mechanisms (e.g., stirring, lifting, rotating, etc.): Based on your needs, you can also equip these with an inverter to implement multi-step speed or jog functionalities.
2. Control Method Selection
   • To allow flexible speed adjustment, operators may directly set the speed on the inverter’s front panel using the built-in knob (local control mode), or use an external analog signal (0–10V/4–20mA from a PLC or industrial PC) as a remote speed reference.
   • If the machine requires centralized automation control (e.g., unified operation from an HMI, production line linkage, recipe management), you can add a small PLC (e.g., Hailipu’s PLC, Mitsubishi FX series, Xinje, Delta, etc.) and an HMI (touch panel) to manage start/stop commands, frequency references, alarm display, and more.

Below, we address main circuit wiring, control circuit wiring, parameter settings, and how to select/connect a PLC/HMI.

II. Main Circuit Wiring

1. Motor-to-Inverter Connection
   • Inverter Output Terminals: U, V, W → Connect to the three-phase terminals of the blower/fan motor (if you have a single-phase motor, this will not be suitable unless you use a model that supports single-phase output).
   • Inverter Input Terminals: R, S, T → Connect to the three-phase AC supply (for single-phase 220 V models, connect to R and T).
   • Ground Terminal PE: Must be reliably grounded to prevent leakage, interference, and induced voltages.
   Refer to the “3.3 Main Circuit Wiring Diagram” in the manual.
   For smaller motor power ratings (e.g., 0.75 kW to 1.5 kW), the HLP-C100 series is usually sufficient. Ensure that the motor’s rated power, voltage, and current match the inverter’s specifications, leaving some margin.
2. Peripheral Protection and Input-Side Components
   • Circuit Breaker (Air Switch): Selected based on the inverter’s rated input current (see “3.2.1 Air Switch, Fuse, Contactor Selection” in the manual) to cut power promptly under overcurrent or other serious faults.
   • AC Contactor (optional): Avoid using it too frequently for starting/stopping the inverter. Typically, it’s only used for maintenance or emergency power-off situations.
   • Input Reactor/EMI Filter (optional): If the site has harmonic issues or other sensitive equipment, consider adding an input reactor or EMI filter on the supply side to reduce higher-order harmonics and electromagnetic interference.
3. Brake Unit and Brake Resistor (optional)
   For a “blower” load, inertia is usually not large, and fast, frequent deceleration is rarely required, so you typically do not need an external brake unit/resistor. But if this inverter is used with higher-inertia loads or requires rapid stops (such as certain conveying or feeding mechanisms), you may consider using the built-in or external brake unit plus an appropriately sized brake resistor.
4. Main Circuit Diagram (Text Example) Power R ——┐ │ Power S ——┤—— [Circuit Breaker] —— [HLP-C100 Inverter] —— U —— Motor (UVW) │ V Power T ——┘ W Inverter PE ———— Ground (Earth) (The above example shows a three-phase 380 V connection; for single-phase, omit S and connect R/T to the live/neutral wires.)

III. Control Circuit Wiring

Control circuit wiring determines how the inverter receives start/stop, direction, and frequency commands, and how it outputs fault and run signals. If you need to use a PLC or external buttons for control, refer to the following.

1. Digital Inputs (DI)
   • The HLP-C100 provides five digital input terminals (FOR, REV, DI1, DI2, DI3) configured as NPN by default (see “3.4 Control Circuit Wiring” in the manual).
   • Typically, FOR is set as the “forward run” command, REV as “reverse run” (if necessary), and the remaining DI1, DI2, DI3 can be set up for multi-step speed selection, emergency stop, reset, jog, etc.
   • For a blower needing only forward run and stop, you can place an external “START” button (normally open) and a “STOP” button (normally closed) to the respective terminals. For example:
     • FOR = Start (via a normally open button + 24 V power; pressing it gives a high-level signal to the inverter)
     • DI1 = Stop (via a normally closed button + 24 V; pressing it breaks the circuit, giving a low-level signal to stop)
     • Or you can assign “start-stop in one” to FOR (reverse logic).
2. Analog Input (VI)
   • If you want to adjust blower speed remotely using an external analog signal (0–10 V / 4–20 mA from a PLC or sensor), wire the signal to VI and GND on the inverter.
   • In the parameters (e.g., C03.15, etc.), select “Reference Source 1 = VI,” and calibrate the range in C06.10~C06.19 to match your actual voltage or current signal.
3. Relay Output (FA-FB-FC)
   • If you want a dry contact output from the inverter to indicate a fault or run status, set parameter C05.40 (Relay Output Function) to 9 (Fault), 5 (Running), etc. Then a PLC or external indicator can monitor the inverter state.
4. Control Circuit Diagram (Text Example) [+24V] —— Start Button (NO) ——> FOR terminal on inverter —— Stop Button (NC) ——> DI1 terminal on inverter GND ---------------------------------> Inverter GND Analog: PLC AO(0-10V) ——> VI PLC AGND ——> GND Relay Output: FA-FB-FC (FB is common, FA is NC, FC is NO) (If you are only using the inverter’s keypad for start/stop and knob for speed, you can omit the digital inputs or just keep a dedicated emergency stop.)

IV. Key Parameter Settings (Example)

Suppose the motor is 0.75 kW, rated voltage 380 V, rated frequency 50 Hz, rated current 1.8 A (example). You want to control start/stop with external FOR and DI1, and 0–10 V analog for speed. Below are key configuration points (see the manual’s “Chapter 5–7: Function Parameter Table” and “Quick Application Guide” for details):

1. Motor Parameters (Group 01)
   • C01.20 = Motor Power = 0.75 (kW)
   • C01.22 = Motor Rated Voltage = 380 (V)
   • C01.23 = Motor Rated Frequency = 50.0 (Hz)
   • C01.24 = Motor Rated Current = 1.80 (A)
   • C01.25 = Motor Rated Speed = 1440 (rpm) (example)
2. Operating Mode
   • C01.00 = 0 (Open-loop speed)
3. Reference Frequency and Acc/Dec (Group 03)
   • C03.03 = 50.00 (Max Reference; set to 50 if you want up to 50 Hz, or higher if you want 60 Hz, etc.)
   • C03.15 = 1 (Reference Source 1 = “Terminal VI”)
   • C03.41 / C03.42 = 5.0 s / 5.0 s (Acceleration/Deceleration time; adjust as needed for the blower’s inertia)
4. Start/Stop & Direction Control (Group 05)
   • C05.10 (FOR Input Function) = 8 (“Start”)
   • C05.12 (DI1 Input Function) = 6 (“Stop, inverse logic”) or 46 (“Stop, normal logic”)
   • If reverse is not required, set C04.10 (Motor Run Direction) to 0 to allow only forward operation, preventing accidental reverse.
5. Analog Input (Group 06)
   • C06.19 = 0 (Indicates VI is a voltage input)
   • C06.10 = 0.00, C06.11 = 10.00 (0–10 V corresponds to 0–50 Hz)
   • If you need a zero deadband, set C06.18 accordingly; if the input fluctuates too much, increase C06.16 (filter time), etc.
6. Protections and Warnings
   • C04.58 = 0 (Motor phase-loss detection; set to 1 if you need it)
   • C14.01 = 5 (Carrier frequency, typically 4–6 kHz is fine; lower it if there’s high EMI)
   • Other defaults (overcurrent, overvoltage, overheat, external faults, etc.) already provide complete protection but can be tuned further if required.
7. Other Common Functions
   • Multi-step Speed: Use DI1, DI2, DI3 in combination to set up multi-speed operation (e.g., fast, slow, jog).
   • PID Control: If you want to control blower pressure or airflow precisely, set C01.00=3 (Process Closed Loop) and configure the PID parameters in Group 07 along with a feedback sensor signal on VI.
   • Jog: Use C03.11 for jog frequency, and assign a DI (e.g., FOR or DIx) to “jog function.”

V. Using a PLC / Touch Screen / Industrial PC (If Needed)

1. PLC Selection
   • For simpler requirements (start/stop, speed reference, minimal I/O), choose a low-end PLC (e.g., Hailipu, Delta, Xinje, Mitsubishi FX1S/FX3U, etc.).
   • For more comprehensive linkage (e.g., multi-station synchronization, multi-step speeds, fault interlocks), select a mid-range PLC with sufficient I/O.
   • Communication: The HLP-C100 features RS485 (Modbus RTU). If your PLC has RS485, you can connect them directly with twisted-pair wiring. Through PLC registers, you can read/write the inverter’s operating status, fault info, frequency commands, etc.
2. Touch Screen / HMI / Industrial PC
   • If you need HMI operation, you can choose a 7” or 10” screen (e.g., Weintek, Kinco, Hailipu HMI) integrated with the PLC. Alternatively, the HMI can connect directly to the inverter over Modbus RTU.
   • In the HMI configuration software, set the inverter station address, baud rate, and parity (matching C08.31, C08.32, C08.33) for reading and writing the inverter’s registers. This allows remote start/stop, speed setting, alarm monitoring, parameter/recipe management, etc.
   • The same applies to an industrial PC, which can connect via serial RS485 or via a USB/RS232-to-RS485 converter.
3. Wiring and Precautions
   • RS485 Interface: Inverter terminals RS+ and RS- correspond to the PLC’s D+ and D-. Make sure to include the 120 Ω termination resistor if required (move jumper J1 on the inverter to ON or add an external resistor).
   • For multiple inverters on one bus, assign distinct addresses (C08.31) and ensure the same baud rate (C08.32) and data format (C08.33).

VI. Wiring and Control Diagram Examples (Dashed-Line Version)

Below is an example for a three-phase 380 V supply, with external push-button start/stop and analog speed control:

              Three-phase AC380V
       R ——┐
       S ——┤—— [Circuit Breaker] ——> [HLP-C100 Inverter] ——> U ——> Blower Motor
       T ——┘                                         V
                                                   W
            PE ————————————> Protective Ground


Digital Control:
   +24V (From PLC or external supply) —— Start Button (NO) ——> FOR (inverter)
                                      —— Stop Button (NC) ——> DI1 (inverter)
   Inverter GND —————————————————————> +24V Supply GND

Analog Signal:
   PLC AO(0–10V) ——> VI (inverter)
   PLC AGND       ——> GND (inverter)

Relay Output (optional):
   FA-FB-FC (FB is common; FA normally closed, FC normally open)
   ——> PLC input or alarm indicator

RS485 Communication (optional):
   PLC D+ ——> RS+  (inverter)
   PLC D- ——> RS-  (inverter)
   Common: PLC COM ——> COM (inverter)

If you only wish to use the inverter’s built-in keypad for start/stop and speed adjustment, there is no need for external push buttons—just ensure C00.40 (HAND Key), C00.42 (AUTO Key) are enabled (default). For speed reference, set C03.15=21 (panel potentiometer).

VII. Conclusion

1. Advantages of This Scheme:
   • You can flexibly adjust the blower motor speed (frequency) as required by the desiccant packaging process.
   • Via external push buttons or PLC/HMI, you can seamlessly switch between automatic and manual control, improving efficiency and convenience.
   • The inverter includes robust built-in protection features to safeguard both the motor and itself.
2. Optional and Extended Features:
   • If your machine requires multi-station linkage or advanced remote monitoring, choose a more capable PLC/HMI and leverage RS485 (Modbus RTU) for centralized control.
   • If harmonic interference is severe, add an input reactor or EMI filter.
   • For rapid braking or high-inertia loads, you can configure a brake unit and suitable brake resistor.
   • If the ambient temperature exceeds 40 °C, derate the inverter or use enhanced cooling to ensure reliable operation.

By following the principles of correct model selection, standardized wiring, and proper parameter configuration, you can fully harness the speed-regulating advantages of the HLP-C100, thereby enhancing the performance and stability of your desiccant packaging machine.