Step-by-Step Motor Parameter Entry and Autotuning on INVT VFDs
Quick commissioning of INVT variable frequency drives in the GD10, GD20, and GD200A series starts with writing the motor nameplate specifications. The basic motor settings are stored in parameter group P02. Without entering these values, the drive cannot calculate the mathematical model of the asynchronous machine. This leads to incorrect motor thermal protection and reduced starting torque on the shaft.
Before configuration, check the metal nameplate of the motor and note down the following values for entry into the drive memory:
- P02.01 — Rated motor power in kW. This parameter determines the limits for overcurrent protection.
- P02.02 — Rated motor frequency in Hz. For standard power grids in Ukraine, this value is 50 Hz.
- P02.03 — Rated motor speed in RPM. This takes into account the slip of the asynchronous motor.
- P02.04 — Rated motor voltage in V. When connecting a three-phase motor to a single-phase 220V drive, the windings are connected in a delta configuration and 220 is entered. For a three-phase 380V line, a star connection is used and 380 is entered.
- P02.05 — Rated motor current in A. The drive uses this value to determine motor overheating.
After filling out group P02, proceed to the motor autotuning procedure. This is configured using parameter P02.07. It offers two options for the test:
- P02.07 = 1 (Dynamic Autotuning): Rotational test. The motor shaft must be decoupled from any mechanical load (belts removed, couplings disconnected). The drive will run the motor up to its rated speed to measure winding inductance and no-load current. This provides the highest accuracy for vector control.
- P02.07 = 2 (Static Autotuning): Locked-rotor test. Used when the motor cannot be decoupled from the gearbox, pump, or conveyor. The drive applies measurement current pulses to the windings without rotating the shaft.
To start the selected test, set parameter P02.07 to 1 or 2, exit the programming menu, and press the RUN key on the drive keypad. The test indicator will start flashing on the display. The process finishes automatically when the screen returns to the standard frequency display mode.
Control of Speed and Run Commands via Terminals
To transfer control of the motor from the built-in keypad to an external operator panel, control cabinet, or PLC, use the reconfiguration of command and speed sources. For this, configure two main parameters — P00.01 and P00.06.
First, define the motor run command source using parameter P00.01:
- P00.01 = 0 — Start and stop commands are executed only using the RUN/STOP keys on the drive keypad.
- P00.01 = 1 — The start command is received from external digital terminals S1-S4. This is the primary industrial mode of operation.
- P00.01 = 2 — Control via Modbus RTU protocol through the RS485 serial port.
Next, configure the operating frequency source in parameter P00.06:
- P00.06 = 0 — Speed is adjusted using the up/down keys on the built-in keypad.
- P00.06 = 1 — Frequency reference is set via analog input AI1. An external potentiometer with a resistance of 1 to 10 kOhm is used (0-10V voltage signal).
- P00.06 = 2 — The signal is received at analog input AI2. Typically, industrial pressure or temperature sensors with a 4-20 mA current signal are connected here.
- P00.06 = 3 — Frequency is adjusted by turning the potentiometer knob built directly into the drive keypad (available on GD10 and GD20 series).
To configure the digital inputs of the terminal strip, go to group P05. By default, input S1 is configured for the forward command, and S2 is configured for the reverse command:
- P05.01 = 1 — Assignment of terminal S1 as forward run (FWD).
- P05.02 = 2 — Assignment of terminal S2 as reverse run (REV).
The wiring diagram for external buttons is based on switching signals to a common point. By default, INVT VFDs use NPN logic (sinking). This means that to activate the Forward command, you connect terminal S1 to terminal COM via a dry contact of a button or an intermediate relay. No external voltage should be applied to these terminals.
The response time of the drive is regulated by two acceleration and deceleration registers:
- P00.11 — Acceleration time 1. Defines the number of seconds the motor takes to accelerate from zero to maximum frequency. The setting range is from 0.1 to 3600.0 seconds. For light fans, 5-10 seconds is usually enough; for heavy flywheels, increase it to 30-60 seconds.
- P00.12 — Deceleration time 1. Defines the motor stopping time from maximum frequency to a complete stop. The range is 0.1 to 3600.0 seconds. Setting a time that is too short with high inertia will trigger an overvoltage fault.
We have a large stock of auxiliary equipment in our Kyiv warehouse, including braking resistors and pressure sensors compatible with these inputs. Read more about motor operation in the guide Frequency converters for electric motor control.
Single-Phase Motor Connection without Capacitor: Practical Hack
In the installation of ventilation and pumping systems, there is often a need to regulate the speed of a single-phase 220V motor. Traditional connection via phase-shifting capacitors when working with a VFD causes serious problems — capacitors heat up, create resonance, and cause sine wave distortions, risking damage to the IGBT module. Professional installers use a proven practical hack: connect the motor directly to the three-phase output of the drive after removing the capacitors.
A single-phase asynchronous motor has two internal windings — the main (running) winding and the auxiliary (starting) winding. The connection diagram without a capacitor is performed according to the following steps:
- Completely remove the starting and running capacitors from the motor terminal box.
- Identify the winding ends using a multimeter. The running winding has lower resistance, while the auxiliary winding has higher resistance.
- Connect one end of the running winding and one end of the auxiliary winding together. This will be the common point.
- Connect the common point to the output terminal U of the frequency inverter.
- Connect the other free end of the running winding to the output terminal V of the drive.
- Connect the other free end of the auxiliary winding to the output terminal W of the drive.
Because the variable frequency drive is designed for a symmetrical three-phase load, connecting only two windings will trigger immediate protection trips. To bypass this limitation, you must disable phase loss detection in the service parameters of the device:
- P11.07 = 0 — Disable input phase loss protection (iPF). This prevents the drive from blocking operation if a three-phase drive model is powered from a standard single-phase 220V grid.
- P11.08 = 0 — Disable output phase loss protection (oPF). Without this, the drive will turn off the output current due to the asymmetrical load on terminal W relative to V and U.
Note that the starting torque of a single-phase motor with this connection will be slightly reduced. This hack is well-suited for centrifugal pumps and fans, but it is not recommended for compressors or lifting mechanisms where full starting torque is required from zero speed. For more details on the specifics of household motors, read the article For domestic use.
Comparison Table of GD10, GD20, and GD200A Series Specifications
The INVT brand manufactures several lines of frequency inverters that differ in functionality, hardware, and application area. To make the right choice of equipment for a specific task, let us compare the three main series that we supply from stock:
| Specification / Series | Goodrive10 (GD10) | Goodrive20 (GD20) | Goodrive200A (GD200A) |
|---|---|---|---|
| Power Range | 0.2 kW — 2.2 kW | 0.4 kW — 110 kW | 0.75 kW — 500 kW |
| Control Modes | Voltage/Frequency (V/F) only | Sensorless Vector Control (SVC), V/F | Sensorless Vector Control (SVC), V/F |
| Braking Unit | None (external cannot be connected) | Built-in for models up to 37 kW | Built-in for models up to 30 kW |
| Load Type | Light, general purpose | Heavy (conveyors, extruders) | Dual rating (G/P types) |
| Analog Inputs | 1 input (AI1) | 2 inputs (AI1, AI2) | 2 inputs (AI1, AI2) |
| RS485 Interface | Built-in Modbus RTU | Built-in Modbus RTU | Built-in Modbus RTU |
The GD10 series is suitable for the simplest ventilation systems and small machines where there are no heavy starting loads. The GD20 models have full vector control and a built-in braking chopper, making them an excellent choice for cyclic and conveyor lines. The GD200A series is the flagship for industrial pumping stations due to dual power rating support (one drive can control a heavy G-type motor or a lighter P-type pump motor). For more details on applications in water supply systems, see the guide for pumps and fans.
Common INVT VFD Faults and Troubleshooting
The operation of an industrial electric drive is often accompanied by emergency shutdowns due to external factors or load mismatch. Let us look at the main fault codes of INVT drives and the specific steps to resolve them:
- OUT1, OUT2, OUT3 (Overcurrent): This error appears during acceleration, deceleration, or constant speed operation respectively. It indicates that the output current exceeded the protection threshold. To resolve this, check the mechanical part for binding. If the mechanics are fine, increase the acceleration time in parameter P00.11 or choose a drive with a larger rating.
- OV1, OV2, OV3 (Overvoltage on DC Bus): Occurs when stopping an inertia mechanism too quickly. The motor enters generator mode and feeds energy back to the drive. To resolve this fault, increase the deceleration time P00.12 or connect a braking resistor. The GD20 series models up to 37 kW have a built-in braking chopper, so the resistor is connected directly to terminals (+) and (PB).
- UV (Undervoltage): The drive detects a voltage drop in the DC circuit below the allowed level. Check the supply line at the input terminals of the device during motor startup. The voltage drop may be caused by insufficient cable cross-section or a weak substation transformer.
When an emergency situation occurs, the drive blocks the output transistors. After resolving the cause of the fault, press the RST/PRG key on the keypad to reset the error and restore operation.
Frequently Asked Questions
How do I reset INVT VFD parameters to factory defaults?
To restore factory settings, use parameter P00.18. Set its value to 1. This will clear all user settings except the stored motor parameters in group P02. After performing the reset, you must reconfigure the start command and operating frequency sources.
Can I run an INVT drive without a motor connected?
Yes, you can run the drive without a motor to check relay logic or configure digital and analog inputs. To prevent the drive from showing an output phase loss fault, disable this protection by setting parameter P11.08 to 0.
What braking resistor resistance should I choose for the INVT GD20 series?
The resistance of the braking resistor must meet the technical requirements of the manual. For example, for a 2.2 kW frequency drive, it is recommended to use a resistor with a nominal value of at least 150 Ohms and a power rating of at least 250 Watts. The connection is made directly to terminals (+) and (PB).
What does a flashing Hz indicator on the keypad display mean?
A flashing Hz LED indicates that the drive is waiting for a run command or the operating frequency has dropped to zero. After a start command is given via terminal S1 or the RUN key, the indicator will light up continuously, signaling that the drive has reached the operating frequency.
How do I configure automatic restart after brief power failures?
Automatic restart is controlled by parameter P08.06, which defines the number of allowed auto-restart attempts (for example, set it to 3). The delay time between start attempts is configured in register P08.07. This allows the system to start without operator intervention after line voltage is restored.
Conclusion
Configuring an INVT frequency drive does not require special software — all operations are performed directly from the built-in keypad using a few key registers. Our engineers recommend always starting with motor parameters and running an autotune before operating the drive. If you need certified INVT Frequency Inverters or professional selection of auxiliary equipment, browse our catalog. In our Kyiv warehouse, we always have a large stock of models for any industrial application.
