Variable Frequency Drives - Wire-Setup-Troubleshoot VFDs

In this introductory lesson, you will gain an understanding of applications that use VFD technology. You will also understand why VFDs are referred to as Inverters and why the electric motor connects to the inverter section of a VFD.

In this lesson you will be able list some benefits of installing variable frequency drives.  You will also understand what a linear and non-liner load is and how VFDs can affect the electric power system.

Selecting a VFD for an application is discussed in this video. VFD installation considerations are also covered.  You will learn about different types of equipment and how their load characteristics determine the type of VFD that will be installed and how it will be setup.  You will also gain knowledge about VFD installation requirements.

In this lesson you will learn about different types of motors used with VFDs.  You will also gain knowledge about installing a VFD and connecting it to an existing motor that was not previously controlled by a VFD.

In this section you will:

1. Become aware of the hazards while working with VFDs.

2. Learn about electrical & mechanical hazards that are present when commissioning VFD systems & how to eliminate these hazards in a professional manner.  

3. View a DC bus measurement using a test meter & a VFD operator display.

4. Know both IEC & NEMA terminal markings for VFD power connections.

5. Become familiar with VFD power input, output, DC bus brake resistor & DC link connections.

6. Understand why reactors are used with VFDs.

7. Know the different wiring configurations for line, DC and load reactors.

8. Understand braking resistor requirements for VFDs and how they are connected to the VFD DC bus.

This video lesson outlines the hazards involved in working with VFDs and electric motors.

After viewing this video lesson you will:

1. Learn which hazards are present and how to deal with them in a professional manner.

2. Understand the hazards associated with:

• Line voltage

• DC bus voltage

• Auto-tuning & controlling the drive remotely with software

In this video lesson:

1. You will see how the VFD DC bus stores electrical energy. 

2. You will also become aware of the VFD DC bus charge LED and why it is important to ensure that the charge LED shuts off after a VFD has been de-energized.

In this video lesson:

• I have set up an Allen-Bradley PowerFlex4 VFD to demonstrate how to read the DC bus voltage on the display screen.

• I quickly change the speed of the motor to show how the DC bus voltage changes during quick deceleration ramps or possible braking scenarios.

• As an added bonus, I show you how to adjust the transistor switching rate or "carrier frequency" to have a quieter running drive and motor.

This video lesson covers the power connection wiring of common variable frequency drives.

After viewing this video lesson you will be able to:

1. Identify line input, motor output & DC bus connections on a VFD.

2. Identify NEMA & IEC dual terminal marking.

3. Layout the proper installation of motor cables and conduits. 

4. Describe the hazards of incorrectly wiring VFD power connections.

In this video lesson:

1. Three different VFDs are shown.

2. All three of the drives are panel mount units, with one of the units having a NEMA 1 kit added.

3. The kit allows an installer to connect conduit fittings or cable strain reliefs and mount the drive on a vertical surface in a building. 

4. The Mitsubishi VFD is shown to expose you to different terminal layouts that you may encounter in the field.

After watching this video you will:

1. Know different methods for terminating VFD power connections.

2. Understanding the importance of creating clean terminations with no bare strands or copper conductor showing.

3. Understand the importance of securely re-installing wiring finger safe guards.

4. Know how to use  a ferrule or ring terminal to connect a wire to a terminal.

After watching this video you will:

1. Know the difference between a panel mount drive and a drive with a NEMA 1 rating.

2. Know how to make power terminations using stranded conductors in a clean and professional manner.

3. Understand the importance of neatly tucking wires, replacing finger safe covers and keeping control and power wires separate.

4. Learn what a NEMA 1 / UL Type 1 enclosure kit is.

After completing this lecture , you will be able to:

1. List why reactors are used with VFDs.

2. Identify troubleshooting scenarios that could be solved by installing a reactor.

3. Explain the difference between the application & installation of Line, DC & Load Reactors.

4. Recognize reactor line and load electrical drawings.

5. Understand how the reactor filters current.

6. Know the two basic impedance values for reactors.

After completing this lecture , you will be able to:

1. Identify VFD applications that would require the installation of a dynamic braking circuit.

2. Understand how DC bus excess energy is diverted to a braking resistor.

3. List installation requirements for VFD dynamic braking components

4. Understand that preventative measures can be taken to avoid the installation of braking resistors.

In this section you will:

1. Gain an understanding of the different types of control connections on a VFD.

2. Fully understand what sink and source means when applied to VFD inputs.

3. Know the operational difference between 2-wire & 3-wire control when applied to VFDs.

4. Understand important setup considerations when using 2 & 3-wire control and how each responds to circuit trips & power failures.

5. You will understand what "disregard run command at power up" means and how to modify this setting to allow a system to run on resumption of power, if required by the application.

6. Setup motor parameters and test the operation of a VFD.

7. Use a programming simulator to configure and test a VFD & motor system.

8. Learn that multiple functions can be assigned to one VFD digital input.

This video lesson introduces VFD control connections. After viewing the lesson you will:

1. Gain knowledge of the different types of VFD control connections and signal types.

2. Understand that VFD inputs and outputs can have multiple functions assigned to each.

3. Understand that VFD relay outputs can be assigned to faults or other VFD status variables.

4. Learn basic rules applied to VFD control connection wiring.

After completing this video lesson you will:

1. Recognize and interpret wiring diagrams that contain either sink or source configured inputs.

2. Understand what a sink wired input is.

3. Understand what a source wired input is.

4. Know that a dip switch or parameter may need changed in order to configure the correct wiring type (either sink or source).

In this video lesson VFD sink and source wiring are covered in the VFD set-up manual and by demonstrating drawing out each type of connection. After viewing the video you will:

1. Recognize wiring connections that are configured either sink or source on the ATV12 variable frequency drive.

2. Know how to complete a schematic for each type of wiring configuration.

3. Know that a parameter must be programmed in the VFD to change from source (factory setting) to sink wiring.

This video lesson explains the PowerFlex4 sink and source wiring connections. The example wiring diagrams in the manual are shown and explained. The wiring type dip switch is shown and discussed also. A diagram using sink wiring and source wiring is drawn in the video. After viewing the lesson, you will:

1. Understand how sink and source wiring is set-up on an Allen-Bradley PowerFlex4 VFD.

2. Know how to draw a schematic diagram using common control devices in sink and source configuration on a PowerFlex4 VFD.

3. Understand DIP switch settings on an Allen–Bradley PoweFlex4 VFD with respect to sink and source wiring.

4. Gain knowledge of the factory installed control wire jumper and understand its purpose.

This video lesson explains how a VFD is wired and operates in 2-wire control mode. After viewing this video lesson, you will:

1. Understand how a VFD operates in 2-wire control mode.

2. Know what “automatic mode” is.

3. Know how VFDs respond after a power failure when operating in 2-wire control mode.

4. Be able to recognize and understand the wiring connections for 2-wire control devices.

This video lesson explains how a VFD is wired and operates in 3-wire control mode. After viewing this video lesson, you will:

1. Understand how a VFD operates in 3-Wire control mode.

2. Become familiar with applications that require 3-wire control

3. Know how a VFD responds to power failures when operating in 3-wire control mode.

4. Understand pulse control and fail-safe circuitry when applied to VFD 3-wire control.

5. Be capable of reading electrical schematics that contain 3-wire configurations and understand how these configurations interact with the VFD digital inputs.

This video lesson explains how a VFD operates in 2-wire control mode. Operation is demonstrated on hardware using a selector switch example and a pumping application example. After viewing the lesson, you will:

1. Understand how a VFD operates in 2-wire control mode.

2. Learn how a VFD operates after a power failure in 2-wire factory default mode.

3. Gain knowledge of the setting "dis-regard run command at power up" and understand why this setting needs to be considered when setting up an application controlled by a VFD.

4. Know the importance of testing how a VFD controlled system behaves after a power failure.

This video lesson explains and demonstrates using actual hardware, the operation of 3-wire control. Operation after power failure and multi-function inputs are explained and demonstrated. After viewing the lesson you will:

1. Understand how a VFD operates in 3-wire control mode.

2. Know what type of control devices are used in 3-wire control.

3. Understand that a normally closed stop push button must be used in this mode and understand that this is a fail safe circuit.

4. Know that a parameter change is required to change from 2-wire control to 3-wire control.

5. Gain knowledge of how multiple functions can be assigned to a single digital input.

This video describes how to connect a digital control device and an analog speed reference (potentiometer) to a Yaskawa GA500 VFD.  The video also demonstrates how to use the GA500 programming simulator.

After completing this video lesson you will:

• Understand how a thermostat is connected to a Yaskawa GA500 VFD and how it is used to start the VFD.

• Understand how a potentiometer is connected to the GA500 and how it is used to control the speed of the VFD.

• Have a basic understanding of how use the Yaskawa GA500 programming simulator.

• Learn valuable VFD setup information such as; application presets, disregard run command on power up, motor setup parameters and basic settings such as acceleration and deceleration.

• Understand sink and source wiring on the GA500 drive.

Please view the attached resources, these are "as is" and for general interest purposes only!

• GA500 Quick Start

• Marathon Y364 3-phase motor data - (information used for basic 1 HP motor programming data).

• GA500 Programming Simulator - used to help get familiar with the GA500 keypad and parameter list.

• SkyCad GA500 drawing template  - (requires free SkyCad program).

SkyCADElectrical™  drawing software

• This is the free version of SkyCADElectrical™.

• You will need to register with an email to use it.

After viewing this lesson you will be able to:

• Identify the wiring connections required to operate an Allen Bradley PowerFlex4 VFD in two speed operation.

• Connect control wiring, check the sink/source dip switch setting and test the system for correct operation.

• Set up the required parameters to operate the drive in a two speed application.

• View the Allen Bradley quick start guide or the user manual and highlight important information related to setting up the drive.

• Set up an Allen-Bradley VFD to operate in "Level Sense" and "Start at Startup" mode.

• Understand that only certain applications can utilize "Level Sense and "Start at Startup" mode.

• Understand how a two speed pump operation can save energy.

Please view the attached resources, these are "as is" and for general interest purposes only!

• PowerFlex4 User Manual with highlighted information and required parameters.

• PowerFlex4 Quick Start

• SkyCad powerFlex4 drawing template  - (requires free SkyCad program).

• Marathon G538A 3-phase motor data - (information used for basic 1 HP motor programming data).

• AB PowerFlex4 two-speed pump parameter list.

SkyCADElectrical™  drawing software

• This is the free version of SkyCADElectrical™.

• You will need to register with an email to use it.

This video describes how to connect a Schneider Electric ATV12 VFD to operate in 3-wire control mode in both forward and reverse directions. It also describes how to connect a potentiometer to be used as a speed reference.

After completing this video lesson you will:

• Understand how a normally closed stop button, a normally open start forward button, and a normally open start reverse button are connected to an ATV12 VFD, to control it in 3-wire control mode.

• Understand how a potentiometer is connected to an ATV12 VFD and how it is used to control the speed of the VFD.

• Know how to program the ATV12 VFD in 3-wire control mode using the ATV12 getting started guide.

• Know how to set up basic motor parameters using the ATV12 getting started guide.

• Understand that the VFD uses the motor rated current value to protect the motor from sustained overloads.

Please view the attached resources, these are "as is" and for general interest purposes only!

• ATV12 Quick Start.

• Marathon MicroMax Y502 3-phase motor data - (information used for basic 1/3 HP motor programming data).

• SkyCad ATV12 drawing template  - (requires free SkyCad program).

SkyCADElectrical™  drawing software

• This is the free version of SkyCADElectrical™.

• You will need to register with an email to use it.

In this section you will:

1. Learn how to setup Schneider Electric SoMove VFD programming software.

2. Create an offline project in the VFD programming software and adjust common motor and control function parameters.

3. Learn different motor control methods such as pump, performance and volts per hertz and will change those settings as required in the software.

4. View and adjust control functions in the software such as; 2-wire & 3-wire control, level, jog, ramp and speed.

5. Learn how to perform an auto-tuning and adjust the drive switching frequency using drive configuration software.

6. learn how to export a project and get familiar with software functions such as the oscilloscope and monitoring parameters.

This video lesson outlines the steps required to install and setup the ATV12 Variable Frequency Drive commissioning software.  The video also outlines setting up an offline project and also provides a basic overview of the software interface.

After viewing this lesson, a student will be able to:

1. Install and run the required software to program a commercially available variable frequency drive (Schneider Electric ATV12).

2. Create an offline programming project and understand the basic software interface.

In this lesson, I show you how to setup motor parameters using the SoMove variable frequency drive commissioning software.

After completing the lesson, you will be able to:

• Create an offline project using the Schneider Electric SoMove drive commissioning software.

• Read a motor nameplate and setup the motor parameters in the software.

• Find the motor thermal current protection parameter and adjust the value to closely match actual motor current draw.

This video lesson outlines the steps required to connect to the ATV12 variable frequency using the SoMove commissioning software and a USB serial cable.  The auto-tuning function, the command panel and VFD switching frequency adjustment are demonstrated.

After viewing this lesson, a student will be able to:

• Connect to the ATV12 variable frequency drive and perform and auto-tuning.

• Adjust the output transistor switching rate in order reduce audible noise.

This video lesson demonstrates how to set up a VFD controlled ventilation fan using drive commissioning software.  The VFD is setup up in Variable torque mode and tuning adjustments are used to help with low speed operation.

After viewing this lesson, a student will be able to:

1. Read a schematic diagram, view a VFD setup manual and use drive commissioning software to set up a VFD controlled ventilation fan.

2. Setup a VFD in variable torque mode and use VFD tuning functions to optimize system operation at low frequencies.

This video lesson demonstrates how to set up a VFD controlled conveyor using drive commissioning software. The VFD is setup up in constant torque mode and tuning adjustments are investigated to help with low speed operation.

After viewing this lesson, a student will be able to:

1. Read a schematic diagram, view a VFD setup manual and use drive commissioning software to set up a VFD controlled conveyor that operates in both forward and reverse directions.

2. Setup a VFD in constant torque mode and use VFD tuning functions to optimize system operation.

3. Setup DC injection braking and work with the IR compensation parameter to optimize system performance.

This video lesson demonstrates how to set up a VFD that controls a pump in a tank emptying system.  An ultrasonic sensor with an analog output is used to provide a 0-10 Volt signal to the VFD.  The signal changes when the level of the tank changes. If the tank level is low, the pump will operate at slow speed.  If the tank level increases, the speed of the pump will increase to meet demand.  Energy savings can be realized when operating in this mode.

If the ultrasonic sensor fails or the pump can not meet demand, a high level float will be activated and the pump will ramp up to full speed.

After viewing this lesson, a student will be able to:

1. Read a schematic diagram, view a VFD setup manual and use drive commissioning software to set up a VFD controlled tank emptying system.

2. Setup a VFD in pump mode and use VFD tuning functions to optimize system operation.

3. Assign multiple VFD control functions to a single VFD input (second ramp, second speed, second high speed assignment).

4. Setup a VFD to read an analog signal from external analog signal devices such as ultrasonic  sensors.

5. Program low speed time out functions for pumping applications.

This video lesson reviews the use of SoMove drive commissioning software and covers features that were not used in earlier lessons.

After viewing this lesson, a student will be able to:

1. Create an offline VFD project using SoMove VFD setup & commissioning software.

2. Use the SoMove scope capture software to record traces generated by VFD variables such as motor current, motor thermal current,  motor frequency, motor power and line mains voltage.

3. Use the fault management parameters tab to view a historical record of faults.

4. Understand the overall layout and interface of the SoMove drive commissioning software.

After completing Section 5 a Student will be able to:

1. List the tasks involved in maintaining VFDs.

2. Troubleshoot VFD fault codes, list causes and possible remedies. 

3. Monitor VFD status using drive HMI.

4. View a historical record of faults on a VFD.

5. List the steps required to safely perform capacitor reforming on a VFD.

6. Use drive commissioning software to view fault history and troubleshoot a VFD.

7. List different types of fault reset methods.

This video lesson covers the basic steps required in periodic maintenance and inspection of variable frequency drives and motors.  The lesson discusses the importance of regular inspections and maintenance and brings attention to methods used in maintaining equipment.  The life cycle of VFD heat sink fans is discussed in the lesson.

After viewing this lesson, a student will:

1. Be capable of listing tasks that are carried out when performing routine maintenance on VFDs.

2. Understand the importance of clean heat sinks and fans, clean and dry enclosures and secure wiring connections.

3. Understand how conditions of use and environmental conditions determine periodic maintenance schedules.

4. Know the average operating life of a VFD fan.

This video lesson discusses DC bus capacitor maintenance.

After viewing this lesson, a student will:

1. Understand that capacitor life is affected by voltage levels, temperature and conditions of use.

2. Be aware of the need to reform DC bus capacitors in VFDs that are stored without power for more than 12 months.

3. Know where to find information about VFD capacitor reforming.

This short quiz reviews important information covered in regard to VFD maintenance and VFD DC bus capacitor maintenance.

This video lesson provides an overview of a typical manufacturer service document related to maintaining industrial control equipment.  The lesson outlines important information covered in the document.  It is highly recommended that a student read the complete document.

After viewing this lesson, a student will:

1. Be able to describe and list tasks required in maintaining industrial control equipment.

2. Understand the hazards involved in maintaining industrial control equipment and take steps to control such hazards.

3. Realize the importance of the "final checkout" that follows industrial control equipment maintenance.

This video lesson demonstrates how to replace the heat sink fan on a Siemens Micro Master 420 and Allen-Bradley PowerFlex4 VFD.

After viewing this lesson, a student will:

1. List the steps involved in removing and replacing heat sink fans on variable frequency drives.

2. Understand that typical fan replacements may be restricted by surrounding equipment such as; wiring ducts and cables.

This video lesson demonstrates how to reform the DC bus capacitors in a Schneider Electric ATV12 variable frequency drive.  The procedure is carried out as per the instructions in the ATV12 user manual maintenance section.

After viewing this lesson, a student will:

1. List the steps involved reforming the DC bus capacitors in an ATV12 drive.

2. Be confident in safely  performing a DC bus reforming exercise on an ATV12 variable frequency drive.

This video lesson outlines common VFD faults and fault resetting methods.  Manual reset, reset and run, VFD common faults and remedies are discussed in the video.

After viewing this lesson, a student will:

1. List common variable frequency drive faults.

2. List different methods of resetting VFD faults.

3. Understand how the auto reset and run function operates and understand the hazards that can arise when enabling this function.

4. Know that a VFD will stop when faulted and that it will not run until the cause of the fault has been removed and the VFD is reset either manually or automatically.

In this video lesson the YASKAWA GA500 drive programming simulator is used to simulate and reset common drive faults.

After viewing this lesson, a student will:

1. Be able to run the YASKAWA GA500 drive simulator and create drive faults while the drive is in run or stop mode.

2. Know that drive faults can have more than one cause and these possible causes are listed in the GA500 troubleshooting manual (please see attached trouble shooting manual).

NOTE:

See the resources folder for the downloadable drive simulator software.

The drive simulator is provided by YASKAWA America and is available free upon request from YASKAWA America. 

Yaskawa America Programming Simulator Industrial (GA Series). An innovative software tool to simulate programming and operation of a Yaskawa Series AC Drive. The Programming Simulator supports the functions listed in the information screen which is shown on start-up of the simulator function.

This video lesson stresses the importance of using VFD monitoring parameters to troubleshoot and maintain drive and motor systems.   Common monitoring parameters are discussed and demonstrated.

After viewing this lesson, a student will:

1. Know the usefulness of using the monitoring display to view drive and motor variables.

2. Understand that monitoring parameters are read only parameters.

3. List common display parameters that can be viewed in the monitoring display.

In this lesson, an overview of using VFD commissioning software to troubleshoot and monitor a modern drive is discussed and demonstrated.

After viewing this lesson, a student will:

1. Be aware of the capabilities and powerful functions of using drive commissioning software to view fault history and other drive variables.

2. Know how to view drive digital input status for troubleshooting field devices.

3. Be able to set up monitoring variable windows in the software monitoring tab.

This quiz reviews important information about drive troubleshooting and fault management.  Methods of how VFD faults are reset and how a drive responds to a fault are covered.

This section introduction discusses and outlines the requirements for testing electric motors for  open windings, shorts and ground faults.

After completing Section 6 a Student will:

1. Know the steps required to measure winding resistance, resistance to ground and insulation testing for a common VFD controlled induction motor.

2. Understand the effects of ambient temperature on electric motor winding resistance.

3. Understand how high ambient  and high motor operating temperature severely reduce the life of electric motor winding resistance.

4. List the steps in locating a ground fault on the output side of a VFD.

In this lesson, an overview of using an insulation tester (megohmmeter) is discussed and demonstrated.  Important points such as equipment isolation, voltage free device testing and capacitive charging current are demonstrated.  The insulation tester is used to test the dielectric strength of a capacitor, while demonstrating stored charges and how to properly drain those charges.

After viewing this lesson, a student will:

1. List the steps required to perform an insulation test on a common AC induction motor.

2. Understand the importance of isolating devices from circuits in order to test those devices.

3. Describe how to properly drain a stored charge after an insulation test is complete.

4. Know that an insulation tester applies a level of DC voltage to the device under test.

This lesson shows how to apply basic resistance and insulation testing skills to troubleshoot a ground fault on the output side of a VFD.  The lesson also shows how to isolate a fault by dividing the circuit to determine which part of the circuit contains the fault.  important points are covered such as isolating the motor from the drive, locking out power and performing the measurements.

After viewing this lesson, a student will:

1. List the steps required to troubleshoot a ground fault on the output side of a VFD.

2. Be capable of interpreting resistance and insulation test measurements on an induction motor that contains a ground fault.

3. Be able to apply the "divide circuit principle" to determine which part of a circuit contains a fault.

4. Safely measure the resistance to ground using an ohmmeter and insulation tester.

This lesson reviews resistance & insulation testing on a single winding induction motor and shows the results of an open winding (open coil).  This test is followed by a discussion on the effects of temperature on insulation resistance and an insulation test is performed on a dual voltage motor winding. The video concludes with a short review of motor basic motor measurements.

After viewing this lesson, a student will be able to:

1. Describe the effects of a higher or lower ambient temperature on insulation resistance.

2. Understand temperature compensation when used to compare insulation test values and evaluate the information.

3. Use temperature coefficient values to compensate for different ambient temperatures when recording insulation measurements.

4. Understand what an insulation multimeter is.

5. Ring out the windings and perform an insulation test on a common dual voltage nine lead induction motor.