VFD Variable Frequency Drive

Welcome to the ATO online shop, your ultimate resource for everything related to variable frequency drives (VFDs). At ATO.com, we pride ourselves on delivering in-depth technical information and unparalleled support for all your VFD requirements. Whether you're searching for a VFD for small-scale applications or industrial-grade solutions, covering voltages from 110V, 220V, 380V, to 480V and beyond, or require specific features like single-phase to three-phase conversion, we have the tailored solutions to meet your unique needs. With our wide range of VFDs, you're sure to find the perfect option for your specific operational needs.

In addition to our wide variety of VFD options, we provide extensive technical support both before and after your purchase. We've curated an extensive repository of FAQs sourced directly from our valued customers, along with instructional videos covering VFD-related subjects spanning from wiring and installation to operation and troubleshooting. We encourage you to leverage these resources to enrich your understanding and optimize your interaction with variable frequency drives before reaching out to our seasoned engineering team for further support.

Variable Frequency Drive FAQs and Troubleshooting

1. Connecting Motor to Single to Three Phase VFD

Q: How do I connect my motor to your single to three phase VFD? The motor will be used to drive a fan for kitchen exhaust and is quite oversized to deliver enough suction when running derated on low rpm / low torque.
A: Connect your single phase supply to VFD's R&S terminals and connect your motor to U&V&W terminals. E is the ground terminal.

2. Choosing VFD for a 3-Phase Motor

Q: My table saw has a 3 phase 3HP motor and I need a drive. Can I use your 2.2 kW variable frequency drive for it. 10A is good. The saw runs on one speed only will the VFD be a problem?
A: If your motor is 3-phase, 220/230V, and your supply voltage is 1-phase, 220/230V, then recommended 5 hp (4 kW) 1 phase to 3 phase VFD.

3. VFD Installation: Wall Mounting Option with Included Cover Plate

Q: Is the VFD designed to be installed in an enclosure or can it be installed on the wall inside the electrical/mechanical room? If installed on the wall is there a cove plate for the electrical conduit to secure etc?
A: Yes, can be installed on the wall, and the cover will be provided, it is a standard accessory.

4. Variable Frequency Drive Overcurrent Troubleshooting

Q: I am looking for some support with your drives. I purchased 3 of your GK3000 single phase to 3 phase vfd drives in different sizes to install in a customer's shop to run a mill, bandsaw, and lathe. I  hooked up the drive and what I was looking to do was hard the drive on and up to full speed and control the equipment from the controls from their local start/stops. When I bring the drive up and try to start the machine the inrush causes me to get an over-current fault. If I turn the machine on and start the drive it will ramp up fine. Is there a setting I can change to make this work or do I have to run a control wire to tie into the start/stop circuit to make the drive ramp up when we hit start and down when we hit stop?

A:

1. Please note: VFD can only be used to directly control the motor and cannot be used as a power supply for machine tool equipment, otherwise it is prone to failure.
2. Regarding the control of starting/stopping the variable frequency drive through the external button switch, you can refer to the attached quick setup document (Introduction to External Terminal Control).
3. Regarding overcurrent issues, please send us the nameplate pictures of the VFD and motor to further confirm whether the VFD and motor match.

There is also a demonstration video below.

5. VFD Troubleshooting: Inaccurate Multimeter Readings

Q: I connected and ran the VFD as per your instructions. However, when I checked the frequency on 3 phases, one phase seemed broken. One phase reads 60 Hz at zero load and the other phase reads more than 1 kHz in my multimeter. 

Measured Frequency: at zero load when VFD running at minimum speed (zero)

• (U & V) = 60Hz
• (U & W) = 1.6 kHz
• (V & W) = 1.6 kHz

What happens to the VFD? Do you have any idea how to troubleshoot this issue?

A: It is inaccurate to use a multimeter to measure VFD output frequency and voltage. You can run the VFD without load first. Please check whether the operating frequency on the panel can reach 60Hz. Then please use a multimeter to measure whether the voltages at the output terminals U, V, and W are normal. If the output voltage deviation is not large, you can connect the motor. Please run the motor without load to see if the motor can run normally.

6. VFD Operation and Frequency Control for 208V 3 Phase Motor

Q: I am powering the VFD with 208V 1 phase, 60 Hz and I am drawing 208V 3 phase to run the motor. I want to know how low can I go on the frequency front. In addition, will the VFD change to variable torque for the fan application, or will it change the power linearly for the speed of the motor while maintaining the torque constant?
A: Yes, you can run a 208V 3 phase motor by powering the VFD with 208V 1 phase, 60 Hz. The variable frequency drive will change the power linearly for the speed of the motor while maintaining the torque constant, and it can output frequencies as low as 0.5Hz.

7. Variable Frequency Drive for Vehicle Lift Control

Q: I'm trying to set up your single to three phase VFD to run a vehicle lift. I would like to use the existing safety switches and motor controls. 2 questions below:

1. Do the Rev and fwd terminals require closed circuit voltage continuously to operate, or does momentarily cause it to run indefinitely?
2. Can I use the P24 terminal to run through the existing motor controls to operate the Rev and Fwd functions?

A: Our single to three phase VFD does not support direct connection of external control voltage, it can only be connected to COM through the internal control signal terminal.

8. GK3000-1S0022 Drive Operation

Q: I have this drive GK3000-1S0022. I have an issue making it work. The motor is slow notching and drawing high current at low voltage. I have it wired with the caps removed. Also in P9.13, I can only change the parameter from 0 to 1, there is no changing it to 1000 as the manual says.

A:

1. The parameter P9.13 does not need to be set.
2. For our single phase VFD drives, we do not recommend running the single phase motor at low voltage for a long time, otherwise, it will be rough at low revs and drawing high current as you see. And you should use the same input power as the rated voltage of the motor supply to the VFD, it would be better. Also, when the capacitor is non-removable, the single phase motors can be connected to the VFD at any two output terminals (U&V, or U&W, or V&W), see Quick Setup and refer to the parameter setting Introduction, re-set the parameters of the variable frequency drive, and then re-test again.
3. If the VFD still doesn’t work properly, please take us a video for reference, and send us the motor & VFD nameplate "tag", and the wiring diagram of the motor.

9. GK3000 VFD Troubleshooting: No Output Voltage

Q: I have installed a GK3000 single phase VFD, a 3 phase motor is connected. The VFD boots up and there are no alarms. When I run the VFD the display shows the output frequency and output voltage but the motor does not turn and there is no voltage outputting to the motor.

A:

1. Please provide us with a video to show the problem you describe. The video should show that the VFD is running, but there is no output voltage.
2. You can set the VFD parameters: P3.01=10 (restore the factory parameters), run the VFD with no load, and when the frequency runs to 50/60HZ, use a multimeter to measure whether the output terminals U-V and V-W of the VFD have output voltage.

10. VFD and Motor Voltage do not Match

Q: I have purchased GK3000-2S0037 VFD with power 3.7kW, AC 1-phase 220V 50/60Hz input, AC 3 phase 0-220v 0-500Hz output. I am trying to configure it for a 380V 400Hz 24000 RPM 3HP 2 pole spindle motor. Can you provide a program sheet to configure the VFD to this spindle? I have tried and burnt up one spindle already.
A: No, the output voltage of the GK3000-2S0037 you purchased can only be three phase 220V, it cannot be used for a three phase 380V spindle motor, which will burn your motor. If your spindle motor is three phase 380V, and the input power voltage is single phase 220V, it is recommended that you use our 1 phase 220V to 3 phase 380V VFD.

11. Variable Frequency Drive for Pressure Transducer

Q: My application is to use 2 twin 3hp 3 phase centrifugal pumps on the same output manifold and to operate the pumps with twin VFDs. The input voltage is 240 VAC single phase.
I want to use a pressure transducer in the output manifold to maintain the pressure at 50 PSI for a large sprinkler irrigation application. I am interested in how to connect the pressure transducer to two individual VFDs and keep them in sync with each other. Can you offer a solution or design?
A: We recommend you use 2 of GK3000-2S0037.

12. Connecting Pressure Transducer to VFD

Q: I have received the GK3000-2S0022 VFD and I am ready to build the circuits. I am a bit confused as to how to wire my pressure transducer to the VFD properly. The transducer has a 5V DC input with the sensor wire return (green).
A: You need to connect two signal lines GND and VI, connect an external power supply, and then change P1.04 to the maximum value of 4.5, and P1.02 to the minimum value of 0.5.

13. VFD Not Suitable for Powering Electric Drills

Q: I recently purchased a GK3000 VFD to convert a 60 Hz power grid into 50 Hz so I can use tools (grinder and drill). I have connected: Input 1 phase 220 V, 60 Hz (R-S) and output 1 phase 220 V, 50 Hz (U-V). The tools have less power than the VFD but I have a problem: when I use the tools with the GK3000 the output cable from the VFD to the socket and the cable of the tool gets very hot. Why is that? What is wrong?
A: Our VFD can only be used to drive the motor, not as a power source to drive the electric drill, otherwise the VFD will heat up and cause malfunction. It is recommended that you stop using VFD in this way. If you want to change the output voltage and frequency of the power supply, it is recommended that you use a variable frequency converter power supply.

14. VFD Parameter Adjustment for Current Fluctuation Issue

Q: We purchase a GK3000 single phase variable frequency drive for running a single phase pump. We face an issue where the current applied to the pump is higher than the rated current we set in the GK3000 and a while drops to almost zero value. Do you have any recommendation of which parameter of the VFD needs to be changed to avoid that?
A: We recommend that you set the VFD parameters P0.02=2 or 3, P5.04=200, and test again.

15. VFD Installation on Well Pump

Q: I’m installing the GK3000-1S0015 VFD on my well pump and using it as a soft start to reduce the impact on my batteries on my solar system. When I wire it in do I still use my electric control box with the capacitor or does that get replaced with the VFD? Also, this is not a constant pressure system I am still using a conventional pressure switch to turn the pump on and off. I have a 3-wire 1/2 hp pump, can you provide a wiring diagram for this application?

A:

1. The single phase motor can be connected to the VFD without removing the capacitor. The two wires of the motor are directly connected to any two of the U, V, and W terminals of the VFD.
2. If you want to use VFD for constant pressure water supply, you could refer to our video. Please see it below.

Related blog: Constant Pressure Water Supply of VFD

16. Troubleshooting and Resetting a Stuck VFD Frequency

Q: I have a 3 PH to 3 PH, 25HP, 460VAC VFD I have been using for general testing on a pump motor. After some use the 3 phase VFD frequency stopped changing without a power cycle. After the 2nd power cycle, the VFD frequency has entirely stopped moving. The frequency is stuck at 40hz.
I have the P0.01 setting set to 0, meaning I should be able to use the dial to change the frequency as I have done in the past. The P0.01 setting has also been changed to 1 to test if the dial was not working by changing the frequency control selection to the up and down arrow. The Up/Down arrows also do not change the VFD frequency.
Please advise. This unit's only use, to the system it is running, is to vary between 40-60hz, and I can now only output 40hz.

A:

1. You can set P3.01=10 (restore factory default parameters). Note: After entering the parameter P3.01, 2 digits are showing 00, you need to press the shift key >> to move to the tens digit, and then modify the value, and then press the shift key >> to move to the single digit, and set P3. 1=10.
2. Please refer to the attached document to reset the basic parameters of the variable frequency drive, and test again.
3. P0.01 Setting set to 0, meaning You can directly adjust the 3 phase VFD output frequency through the potentiometer on the panel.
4. P0.01 Setting set to 1, meaning you can use the up/down arrows to increase/decrease the frequency output, but the rate of change is very small, only 0.01Hz.
5. Also, if you want to limit the VFD minimum output frequency to 40Hz, please set P0.20=40Hz.