Tag: VLT2800

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User Guide for Danfoss VLT2800 Frequency Converter

Danfoss VLT2800 Frequency Converter User Guide

1. Introduction to the Operation Panel

The operation panel of the Danfoss VLT2800 frequency converter is designed to be simple and user-friendly, allowing users to control basic functions and adjust parameters. The key components of the panel are:

  1. Display Screen: Shows current status, parameter values, fault codes, etc.
  2. Navigation Keys: Used to navigate between menus and parameters, including arrow keys for up, down, left, and right.
  3. Operation Keys: Includes keys for start, stop, reset, and other control functions for easy operation.
  4. Quick Menu Key: Provides quick access to commonly used menus and parameters.
  5. Change Data Keys: These keys allow users to modify displayed parameters and adjust the operating status of the converter.

With these buttons, users can perform parameter settings, switch operating modes, and monitor the running status of the frequency converter in real-time.

VLT2800 Multi Panel Function Diagram

2. Parameter Initialization and Adjustment

When using the VLT2800 frequency converter for the first time or when restoring factory settings, follow these steps for parameter initialization and adjustment:

  1. Restoring Factory Settings:
  • Enter the main menu and select the “Restore Factory Settings” option. The frequency converter will reset all user settings to default parameters.
  1. Motor Parameter Settings:
    Configure the motor parameters through parameter group 102-106:
  • 102: Motor Power (PM,N): Set the motor’s rated power.
  • 103: Motor Voltage (UM,N): Set the motor’s rated voltage.
  • 104: Motor Frequency (fM,N): Set the motor’s rated working frequency.
  • 105: Motor Current (IM,N): Set the motor’s rated current.
  • 106: Motor Speed (nM,N): Set the motor’s rated speed.
  1. Speed Control Mode:
  • Choose between open-loop or closed-loop speed control to ensure precise control based on application requirements.
VLT2800 Control Circuit Wiring Diagram

3. Start/Stop Function and External Potentiometer Adjustment

1. Start and Stop Functions via Terminals

The Danfoss VLT2800 frequency converter can be started and stopped using terminal connections. Follow these steps for terminal wiring:

  • Start Signal: Connect the start signal to terminals 12 (START) and GND. The converter will start the motor according to the set parameters once the signal is received.
  • Stop Signal: Connect the stop signal to terminals 13 (STOP) and GND. The motor will decelerate and stop as per the set deceleration time when the stop signal is triggered.
  • Reset Function: Connect an external reset signal to terminal 16 (RESET) to reset the converter when needed.
2. External Potentiometer for Speed Adjustment

To adjust the output frequency using an external potentiometer, follow these wiring steps:

  • Potentiometer Wiring:
  • Connect the positive terminal of the potentiometer to terminal 55 (+10V output), the negative terminal to terminal 53 (analog input), and ground to GND.
  • Parameter Settings:
  1. In parameter group 300, set the analog input type and configure terminal 53 to be controlled by the external potentiometer.
  2. Adjust parameters 204 (RefMIN) and 205 (RefMAX) to set the minimum and maximum reference values corresponding to the potentiometer.

By adjusting the potentiometer, the frequency converter’s output frequency can be dynamically controlled, allowing for smooth linear speed regulation from minimum to maximum.

4. Fault Code Analysis and Troubleshooting

The VLT2800 frequency converter features a self-diagnostic function. If a fault occurs during operation, the relevant fault code will be displayed on the control panel. Below are some common fault codes and their solutions:

  1. E1: Overcurrent Protection
  • Cause: Fast motor acceleration, excessive load, or motor short circuit.
  • Solution: Check motor wiring, reduce load, or extend the acceleration time.
  1. E2: Overvoltage Protection
  • Cause: Power supply voltage too high or large voltage fluctuations.
  • Solution: Check if the power supply voltage is within the specified range, and use a voltage stabilizer if necessary.
  1. E3: Undervoltage Protection
  • Cause: Power supply voltage too low or a sudden voltage drop.
  • Solution: Ensure stable power supply and check voltage levels.
  1. E4: Overheating Protection
  • Cause: Poor heat dissipation or high ambient temperature.
  • Solution: Check the cooling system of the converter, ensure the fan is working properly, and reduce the environmental temperature or improve ventilation if needed.
  1. E14: Communication Failure
  • Cause: Communication line fault or loss of communication between the controller and the converter.
  • Solution: Inspect communication cable connections and reconfigure communication parameters.

By setting the correct parameters, ensuring proper wiring, and accurately identifying fault codes, users can ensure the stable operation of the Danfoss VLT2800 frequency converter and troubleshoot issues as they arise.

This guide provides users with a comprehensive overview of the VLT2800 frequency converter, covering panel operation, parameter setup, terminal functions, and troubleshooting to help them get started and maintain smooth operation of the device.

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Danfoss VFD VLT2800 (VLT2900) fault err7 and err5 repair process

Danfoss Denmark produced two VLT2800 (2900) low-power (3kW) models, which tripped Err-7 during operation, meaning “overvoltage” and caused the frequency converter to shut down. Sometimes Err-5 is also triggered, with a high voltage warning. The measured three-phase power supply is 400V, which is within the rated range. Use the+key on the operation panel to call up the Ud (main circuit DC voltage) value. When it exceeds 600V, a trip and shutdown will occur.

According to the instructions: When the DC circuit of this model has an undervoltage below 370V, it will trip due to undervoltage; Low voltage warning given at 400V, but still operational; When it is not higher than 665V, a high voltage alarm is given, but it can still operate; When the voltage is higher than 665V -820V, the delayed tripping and shutdown can be described as having an extremely wide voltage protection range!
During the power on inspection, the Ud display value of a machine is unstable, which may be due to a change in resistance in the detection circuit. Diagnosed as abnormal Ud detection circuit. The Ud sampling circuit consists of 8 820k resistors and two 13k resistors connected in series, and their voltage division value is used as the Ud signal. Due to the urgent repair time required by the user, there was no time to thoroughly investigate the subsequent circuit. After connecting 8 820k resistor circuits with another 330k resistor in series, the machine was powered on and tested. When the input three-phase AC voltage was 440V (supplied by the regulator), Err-7 was no longer triggered, so the user took away the installation.
User installation, trial operation, one unit jumps Err-8, undervoltage; One device jumps Err-37 and has poor communication.
Determine if the Ud detection circuit is still faulty. Following the principle of prioritizing ease over difficulty, we will still focus on these 10 resistor detection circuits. Reserve three 820k resistors from the P+end of the power supply, connect a 6V voltage regulator in series and then connect the N end. Connect the 6V voltage regulator in series with a 1M or 100k semi variable resistor. Disassemble one 13k resistor at the signal input end and connect the center end of the variable resistor as the Ud signal. Calculate the Ud sampling voltage. When the input is 380V, it is approximately 2.2V. Adjust the semi variable resistor to output 2.2V at the center end, and define this voltage as U-sampling.
The process of power transmission and debugging is very interesting: when the U voltage is greater than 2.2V, Err-37 jumps when powered on, which means there is a communication failure between the control card and BMC. However, the essence of this phenomenon is that it is not because the communication between the control card and BMC is interrupted that Err-37 jumps, but because the control circuit detects that Ud is really “frighteningly high”, it forcibly interrupts the communication between the control card and BMC, and then jumps Err-37 to give a warning! When the U voltage approaches 2.2V, pressing the reset button can eliminate the Err-37 alarm, and FT-00 will appear on the screen, entering standby mode; When the U voltage is less than 2.2V, the Err-35 will jump when powered on, indicating a startup impulse fault: if the frequency converter repeatedly connects the power supply within one minute, an alarm will be generated. But the essence of this phenomenon is that because the CPU detects that Ud is surprisingly low, it is treated as a low Ud formed by repeatedly starting the frequency converter in a short period of time, and an Err-35 alarm signal is given! When the U voltage is less than 2.2V, the capacitor charging short-circuit contactor is also in the released state. Only when the U voltage is close to 2.2V (i.e. Ud is higher than 400V), this contactor will be energized and the frequency converter will be allowed to enter standby mode.
When FT-00 appears on the screen, press the+key to adjust the Ud value, adjust the variable resistor by half, and make it display 500V stably. At this point, when inputting 220V-460V, the displayed value remains stable at 500V. After installation, it has been running normally.
It should be noted that this can only be used as one of the emergency repair methods, and it is indeed an overvoltage false alarm. Assuming that the undervoltage alarm is caused by the loss of capacity of the DC energy storage capacitor in the main circuit, the cause of the fault must be identified, and the fault must be effectively eradicated before repairing the U-sampling circuit!

Additionally, some models have output voltage that depends on the sampling voltage of the DC circuit, i.e. the output voltage tracks the three-phase input voltage. After such processing, the output V/F ratio will change. But generally it will not affect the use; For vector frequency converters, the DC voltage sampling value affects the control of the output three-phase voltage and current, so the sampling voltage cannot be easily changed!