Learn how Yaskawa AC Adjustable Frequency Drives work, compare GA500 and GA800 platforms, understand VFD applications, and select the right drive for pumps, fans, conveyors, and industrial machinery.
An Overview of Yaskawa AFDs: Functionality, Drive Families, Motor Control, Applications, Features, Sizing, and Selection for Industrial Automation.
Yaskawa AC Adjustable Frequency Drives (AFDs), commonly called Variable Frequency Drives (VFDs), regulate motor speed, torque, acceleration, and deceleration by controlling the frequency and voltage supplied to an AC motor. Yaskawa’s portfolio spans compact microdrives such as the GA500, general-purpose/high-performance platforms such as the GA800 and A1000, and dedicated variable-torque drives for pumps and fans. The correct Yaskawa AFD is selected by matching the motor, load profile, duty rating, voltage, environment, control requirements, braking needs, communications, and application—not simply by matching horsepower.
What Is a Yaskawa AC Adjustable Frequency Drive?
A Yaskawa AC Adjustable Frequency Drive is a power-electronic controller positioned between the incoming electrical supply and an AC motor. Its fundamental job is straightforward: convert fixed-frequency AC power into controlled electrical power whose output frequency, voltage, and motor-control behavior can be adjusted according to the machine’s requirements.
The terminology can be confusing because manufacturers and industries use several names for essentially the same technology. AC drive, adjustable frequency drive (AFD), variable frequency drive (VFD), variable speed drive (VSD), and inverter are commonly used terms. In industrial automation, however, the term VFD remains particularly common.
A typical drive consists of an input rectifier, DC bus, inverter section, control electronics, and protective circuitry. The rectifier converts incoming AC to DC. The DC bus filters and stores that energy, while the inverter rapidly switches semiconductor devices to synthesize the controlled three-phase waveform delivered to the motor.
That control allows the motor to operate at speeds other than its fixed line-frequency speed. Instead of simply starting a motor at full speed and using mechanical devices to restrict the process, the drive can make the motor produce approximately the speed and torque the application actually requires.
This distinction is important. A VFD is not merely an electronic motor starter. It becomes part of the machine’s control architecture.
How Yaskawa VFDs Control AC Motors
For a conventional induction motor, motor speed is primarily related to supply frequency and the motor’s number of poles. A simplified synchronous-speed relationship is:
Ns = 120 × f / P
where:
Ns = synchronous speed in RPM
f = electrical frequency in Hz
P = number of motor poles
The actual induction-motor speed is slightly lower because of slip.
Therefore, reducing the commanded frequency generally reduces motor speed. Increasing frequency raises speed, within the mechanical and electrical limits of the motor and drive.
Modern Yaskawa drives go considerably further than basic frequency control. The GA800, for example, supports open- and closed-loop current-vector control as well as open- and closed-loop V/f control, and supports induction, permanent-magnet, and synchronous-reluctance motors.
V/f Control
Volts-per-hertz control is the traditional approach. The drive maintains an appropriate relationship between voltage and frequency so the motor can develop useful torque over its operating range.
It remains practical for many fans, pumps, conveyors, and general machinery where extremely precise torque regulation is unnecessary.
Open-Loop Vector Control
Open-loop vector control improves torque production and speed regulation without requiring an encoder in many applications. This makes it useful when the machine requires more controlled acceleration, better low-speed performance, or improved load response than basic V/f control can provide.
Closed-Loop Vector Control
Closed-loop vector control adds feedback, normally through an encoder or other speed-feedback device. The drive can therefore compare commanded and actual motor behavior and make corrections.
This becomes valuable when the application demands tight speed regulation, controlled torque, or more demanding machine performance.
Yaskawa AC Drive Product Families
Yaskawa does not use a single drive family for every application. Its industrial AC-drive portfolio is divided according to performance, motor size, application type, environmental requirements, and control requirements.
Yaskawa GA500: Compact Industrial Microdrive
The GA500 is positioned as a compact industrial AC microdrive. Yaskawa’s current selection documentation states that the GA500 can control induction, permanent-magnet, and synchronous-reluctance motors, while its EZ Vector mode simplifies motor setup. It also offers separate Heavy Duty and Normal Duty ratings.
The GA500 is particularly appropriate when panel space, straightforward commissioning, and economical machine-level control matter.
Typical applications include:
Conveyors
Small pumps
Fans
Packaging machinery
Material handling
Machine tools
Small production machines
General OEM equipment
Yaskawa’s documentation also identifies GA500 and GA501 products as microdrives with ratings extending to approximately 40 HP depending on voltage and configuration.
Yaskawa GA800: High-Performance General-Purpose Drive
The GA800 is the more substantial industrial platform and is designed for demanding variable-speed applications.
Yaskawa specifies the GA800 with open- and closed-loop vector control, V/f control, multiple motor technologies, network connectivity, Safe Torque Off, an integrated DC reactor on applicable ratings, and other industrial control capabilities. The platform extends to high horsepower ratings, with Yaskawa listing operation up to 1,000 HP in its industrial AC-drive portfolio.
The GA800 makes sense when the application needs more than basic speed control.
Potential applications include:
Heavy conveyors
Extruders
Compressors
Material handling
Process machinery
Machine tools
Packaging machinery
Industrial pumps
Fans
High-inertia loads
Applications requiring network integration
The GA800 also provides programming and commissioning tools that can reduce engineering and startup effort. Yaskawa identifies DriveWizard Industrial, DriveWizard Mobile, DriveWorksEZ, a Product Selector, programming simulators, an Energy Savings Predictor, and a Harmonics Estimator among its software tools.
Yaskawa A1000
The A1000 remains an important Yaskawa high-performance drive family, particularly in installed bases and applications where its established control architecture is already specified.
Yaskawa describes the A1000 as a full-featured drive extending to 1,000 HP, with network communications, feedback capability, expandable I/O, and applications ranging from fans and pumps to complex machines.
For a retrofit, therefore, the question is not simply whether a newer platform exists. Engineers should examine motor compatibility, existing parameter sets, communications architecture, enclosure arrangement, feedback, braking, spare-parts strategy, and machine certification before replacing an established drive.
P1000 and Variable-Torque Applications
Yaskawa also offers dedicated fan-and-pump drive platforms. Its current industrial AC-drive portfolio identifies FP605 and P1000 under fan-and-pump drives, specifically for variable-torque applications such as centrifugal pumps and fans.
This distinction matters because centrifugal pump and fan loads behave differently from constant-torque machinery. The drive should be selected according to the actual load curve rather than assuming every motor application requires the same type of drive.
Yaskawa VFD Applications
The biggest mistake in drive selection is starting with the drive catalog instead of the machine.
Start with the load.
Ask what the motor is driving, how much torque it requires, how quickly it accelerates, whether the load regenerates energy, whether it operates continuously or intermittently, and whether speed regulation must remain accurate under changing load.
Pumps
Yaskawa VFDs are widely applicable to centrifugal pumps, booster systems, process pumps, cooling-water systems, and other pumping applications.
For centrifugal pumps, reducing speed can substantially reduce flow, pressure, and power demand according to the affinity laws. In simplified form:
Flow ∝ Speed
Head ∝ Speed²
Power ∝ Speed³
That third relationship is why variable-speed control can be particularly valuable on systems that spend substantial operating time below full flow.
Instead of throttling a valve while the pump continues operating at high speed, the drive can reduce pump speed to better match demand.
However, do not assume every pump should run from a standard VFD without engineering review. Positive-displacement pumps, high-static-head systems, minimum-flow requirements, seal arrangements, and process constraints can change the selection.
Fans and Blowers
Fans are another classic variable-torque application.
HVAC air handlers, exhaust systems, cooling towers, ventilation systems, process fans, and industrial blowers frequently operate at changing demand. A properly selected VFD allows airflow to track the actual process requirement rather than forcing the fan to run at maximum speed continuously.
Yaskawa specifically categorizes fan-and-pump drives for variable-torque applications.
Conveyors
Conveyors are common VFD applications, but they should not automatically be treated as simple variable-torque loads.
A conveyor can require substantial starting torque, especially when loaded. Inclined conveyors can also generate regenerative energy during deceleration or when the load drives the motor.
Therefore, conveyor selection should consider:
Starting torque
Acceleration time
Belt inertia
Product weight
Incline angle
Mechanical braking
Regeneration
Required speed range
Duty cycle
Number of starts and stops
For a simple horizontal conveyor, open-loop vector control may be sufficient. A demanding conveyor may require more sophisticated torque control and braking arrangements.
Industrial Machinery
Yaskawa drives can also control machine tools, packaging equipment, mixers, material-handling machinery, compressors, extrusion equipment, and other production machinery.
Here, drive selection becomes more technical.
A machine may need rapid acceleration, high starting torque, precise speed control, controlled stopping, positioning assistance, braking, or synchronization with a PLC.
Consequently, the correct question is not simply, “What horsepower is the motor?”
The better question is:
What must the motor do throughout the entire machine cycle?
How to Select the Right Yaskawa AFD
A reliable selection process starts with the motor nameplate and application data.
1. Determine Motor Voltage
Verify:
Input supply voltage
Motor voltage
Single-phase or three-phase supply
Frequency
Available short-circuit current
Electrical distribution requirements
Never select the drive solely from the motor horsepower.
The voltage class must match the electrical system and the selected drive.
2. Determine Motor Current
Motor full-load current is often more useful than horsepower when selecting the actual drive rating.
Compare the motor’s nameplate current against the drive’s rated output current under the appropriate duty classification.
This becomes especially important when operating motors with unusual efficiency classes, service factors, high altitude, elevated ambient temperatures, or nonstandard operating conditions.
3. Choose Normal Duty or Heavy Duty
This is one of the most important selection decisions.
Yaskawa’s GA500 documentation explicitly distinguishes Normal Duty (ND) and Heavy Duty (HD) ratings. Heavy Duty provides greater overload capability, while Normal Duty can permit operation of a larger motor at the applicable rating.
For example, a centrifugal fan with relatively predictable torque demand may fit a normal-duty application.
A heavily loaded conveyor, hoist-related machine, crusher, or high-inertia application may require heavy-duty capability.
Do not select ND simply because the horsepower appears to match.
4. Evaluate the Load Type
Classify the load as accurately as possible.
Variable-Torque Loads
Typical examples include:
Centrifugal pumps
Centrifugal fans
Cooling-tower fans
These loads generally become easier to control as speed decreases.
Constant-Torque Loads
Typical examples include:
Conveyors
Mixers
Positive-displacement pumps
Extruders
Compressors
Certain machine tools
These applications can demand substantially more torque at reduced speeds.
Regenerative Loads
Examples include:
High-inertia machinery
Rapid deceleration
Descending loads
Certain centrifuges
Unwinding applications
Here, stopping the motor can push energy back toward the DC bus. The drive system may require dynamic braking, a regenerative unit, or another engineered energy-management solution.
Motor Compatibility and Control Method
Modern Yaskawa drives can support multiple motor technologies. The GA500 selection guide, for example, identifies induction, permanent-magnet, and synchronous-reluctance motor compatibility.
Nevertheless, compatibility on paper does not eliminate the need for proper motor data.
Collect:
Motor rated voltage
Rated current
Rated frequency
Rated RPM
Motor power
Motor power factor
Motor efficiency
Motor code or model
Encoder information, if applicable
Then determine whether the application requires V/f, open-loop vector, or closed-loop vector control.
For a simple fan, basic control may be adequate.
For a conveyor requiring strong low-speed torque, vector control may be more appropriate.
For an application demanding tight speed regulation, feedback may be justified.
Braking and Regeneration
Braking is frequently overlooked during drive selection.
When a motor decelerates, mechanical energy does not simply disappear. Depending on the machine, that energy can return to the drive’s DC bus and increase bus voltage.
There are several ways to address this:
Coast to Stop
The motor is disconnected from controlled torque and allowed to slow naturally.
This is simple but unsuitable when controlled stopping is required.
Ramp-to-Stop
The drive actively decelerates the motor over a programmed time.
This works for many applications but may require additional braking capacity if the load has substantial inertia.
Dynamic Braking
A braking resistor dissipates regenerated energy as heat.
This is common where frequent or rapid deceleration is required.
Regenerative Systems
For applications with significant recurring regeneration, a regenerative converter or regenerative drive architecture can return energy to the electrical system rather than dissipating it as heat.
Yaskawa’s current industrial portfolio includes both regenerative and low-harmonic system components, including the D1000 and R1000 families.
Harmonics, EMC and Power Quality
A VFD is a nonlinear power-electronic load. That means its input current waveform is not identical to the sinusoidal current drawn by a simple resistive load.
Consequently, drive systems should be evaluated for:
Harmonic distortion
Power-factor requirements
Line reactors
DC reactors
Passive harmonic filters
Active harmonic mitigation
Electromagnetic compatibility
Long motor-cable effects
The GA800, for example, includes an integrated DC reactor on applicable ratings, while Yaskawa also provides a Harmonics Estimator for evaluating mitigation requirements.
This is particularly important in facilities with large numbers of drives, sensitive instrumentation, generators, UPS systems, or stringent power-quality requirements.
Industrial Communications and PLC Integration
Modern VFDs are no longer isolated motor controllers.
They frequently communicate with PLCs, HMIs, SCADA systems, DCS platforms, and higher-level manufacturing systems.
Yaskawa lists industrial communication options including:
EtherNet/IP
PROFINET
Modbus TCP/IP
Modbus RTU
PROFIBUS
EtherCAT
MECHATROLINK
among its industrial AC-drive communication ecosystem.
A PLC can therefore issue speed references, start/stop commands, torque commands, and other control instructions while receiving drive status, current, speed, fault information, and diagnostic data.
For a new project, select the communications architecture before purchasing the drive. Retrofitting a communication option after the panel is built can create unnecessary engineering work.
Installation and Environmental Considerations
Drive selection does not end with electrical ratings.
The installation environment matters.
Consider:
Ambient temperature
Humidity
Dust
Corrosive gases
Vibration
Altitude
Enclosure rating
Cooling method
Panel ventilation
Motor cable length
Installation elevation
Required derating
Yaskawa provides different enclosure and mounting approaches across its drive families. The GA800, for example, is available in protected-chassis configurations and can also be configured with enclosure arrangements; Yaskawa identifies Type 1, Type 12, and Type 3R options for its GA800 Configured package.
For harsh industrial environments, simply putting an IP20 drive inside an inadequately ventilated cabinet is not a solution.
The entire thermal design must work.
Yaskawa VFD Commissioning and Programming
A properly sized drive can still perform badly if it is commissioned incorrectly.
The basic commissioning sequence should include:
Verify electrical installation.
Confirm motor nameplate data.
Configure control mode.
Configure acceleration and deceleration.
Set minimum and maximum frequency.
Configure digital and analog I/O.
Configure the speed reference.
Configure motor protection.
Configure braking.
Configure communication parameters.
Perform a controlled test run.
Verify actual motor current and operating behavior.
Yaskawa provides DriveWizard Industrial for configuration and troubleshooting, while DriveWizard Mobile can be used with supported newer drives for startup, monitoring, and parameter backup.
DriveWorksEZ can also provide embedded custom logic and mathematical functionality in supported Yaskawa drives.
That capability can reduce the amount of simple machine logic that must reside in a separate controller, although it should be used deliberately rather than turning the drive into an unnecessarily complicated substitute for a PLC.
Common Yaskawa VFD Selection Mistakes
Selecting Only by Horsepower
A 20 HP motor does not automatically mean every 20 HP drive is equivalent.
Current, duty, overload, voltage, load profile, environmental conditions, and braking requirements matter.
Ignoring Heavy-Duty Requirements
A conveyor that frequently starts under load can have very different requirements from a lightly loaded fan.
Using a Standard Drive for a Specialized Load
Regenerative, high-speed, hoisting, long-cable, hazardous-area, and severe-environment applications deserve additional engineering review.
Forgetting Motor Cooling
A motor running continuously at low speed may not receive the same shaft-mounted-fan cooling it receives at full speed.
The motor’s thermal capability therefore needs to be evaluated alongside the drive.
Ignoring Motor Cable Length
Long PWM motor cables can introduce reflected-wave voltage, common-mode currents, and electromagnetic interference concerns. The drive, motor, cable, grounding, and filtering strategy should be considered as one system.
Treating the VFD as a Drop-In Replacement
A replacement drive may have different terminal assignments, parameter structures, communications behavior, braking requirements, or control modes.
For retrofit work, document the existing system before removing the old drive.
Yaskawa AFD Selection Checklist
Before placing an order, confirm the following:
Electrical
Supply voltage
Phase configuration
Frequency
Available fault current
Motor voltage
Motor current
Motor horsepower/kW
Mechanical
Load type
Starting torque
Inertia
Required speed range
Acceleration time
Deceleration time
Regeneration
Control
V/f or vector
Open or closed loop
Encoder requirement
Analog I/O
Digital I/O
PLC interface
Network protocol
Environmental
Ambient temperature
Humidity
Dust
Corrosive atmosphere
Altitude
Enclosure
Cooling
System
Braking resistor
Line reactor
DC reactor
Harmonic mitigation
EMC requirements
Safety requirements
Motor cable length
Bypass requirements
Yaskawa’s Product Selector is specifically designed to help compare applicable drive families based on basic application information and configuration requirements.
Yaskawa AFDs vs. Other Industrial VFDs
The meaningful comparison is not simply brand against brand.
Compare the complete drive system:
Motor-control performance
Drive current rating
Overload capability
Application software
Communications
Safety functions
Braking
Harmonic performance
Enclosure options
Commissioning tools
Spare-parts availability
Existing plant standardization
Lifecycle support
For example, Automation Pioneer currently lists Yaskawa AC Drives within its industrial automation product categories and also maintains a dedicated Variable Frequency Drives category. (Automation Pioneer Product Categories)
Final Thoughts: Selecting the Right Yaskawa VFD
Yaskawa AC Adjustable Frequency Drives cover a wide range of industrial requirements, from compact machine-level speed control to high-performance applications requiring vector control, networking, safety functions, braking, feedback, and advanced diagnostics.
The GA500 is positioned as a compact industrial microdrive, while the GA800 provides a broader high-performance platform with advanced control and integration capabilities. Yaskawa’s portfolio also includes application-focused fan-and-pump drives and established platforms such as the A1000 and P1000.
The critical point is simple: select the drive around the application, not the catalog number.
Start with the motor. Then analyze the load. Determine the required torque, speed range, duty cycle, braking behavior, environmental conditions, control architecture, communications, and power-quality requirements. Once those requirements are defined, selecting the appropriate Yaskawa AFD becomes a technical engineering exercise rather than guesswork.
For industrial automation projects, this approach also makes future maintenance easier because the drive selection is documented against measurable application requirements rather than simply the horsepower printed on the motor nameplate.
Frequently Asked Questions About Yaskawa AC Adjustable Frequency Drives
1. What is a Yaskawa AC Adjustable Frequency Drive?
A Yaskawa AC Adjustable Frequency Drive is an electronic motor controller that regulates the frequency and voltage supplied to an AC motor, allowing controlled motor speed, acceleration, deceleration, and torque.
2. Is a Yaskawa AFD the same as a VFD?
Yes, in most industrial applications the terms AFD, VFD, AC drive, and variable-speed drive refer to the same general category of equipment: an electronic controller that varies AC motor speed by controlling electrical output frequency and voltage.
3. Which Yaskawa VFD is best for industrial applications?
There is no single drive that is correct for every industrial application. GA500, GA800, A1000, P1000, FP605, and other Yaskawa platforms address different combinations of power, control, load type, and application requirements.
4. What is the difference between the Yaskawa GA500 and GA800?
The GA500 is a compact industrial microdrive aimed at machine-level applications, while the GA800 is a higher-performance industrial drive with broader control, communications, safety, and power capabilities.
5. Can Yaskawa VFDs control permanent-magnet motors?
Yes. Current Yaskawa documentation identifies supported drive families such as the GA500 and GA800 as capable of controlling permanent-magnet motor technologies in addition to induction motors, subject to the specific model and application requirements.
6. Can a Yaskawa VFD control a conveyor?
Yes. Yaskawa AC drives can be applied to conveyor systems, but the drive should be selected according to starting torque, inertia, acceleration requirements, braking, load conditions, and duty rating rather than horsepower alone.
7. Are Yaskawa VFDs suitable for pumps and fans?
Yes. Yaskawa specifically offers fan-and-pump drive products for variable-torque applications, including centrifugal pumps and fans.
8. Do Yaskawa drives support EtherNet/IP and PROFINET?
Yaskawa’s industrial AC-drive portfolio supports multiple industrial communication protocols, including EtherNet/IP and PROFINET, along with Modbus TCP/IP, Modbus RTU, PROFIBUS, EtherCAT, and MECHATROLINK options.
9. How do I select the correct Yaskawa VFD size?
Start with motor voltage and full-load current, then evaluate duty rating, load type, overload requirement, speed range, acceleration/deceleration, braking, environment, motor technology, communications, and installation conditions. Yaskawa also provides a Product Selector for comparing appropriate drive configurations.
10. What software is used to program and troubleshoot Yaskawa VFDs?
Yaskawa provides DriveWizard Industrial for drive configuration and troubleshooting, DriveWizard Mobile for supported drive families, DriveWorksEZ for embedded custom logic, and additional tools for product selection, programming simulation, energy analysis, and harmonic evaluation.
Recommended Automation Pioneer Resources
To deepen your understanding of industrial automation, critical factory infrastructure, and digital transformation, explore these related resources on Automation Pioneer:
- AC Adjustable Frequency Drives
- Yaskawa AC Adjustable Frequency Drives (AFDs)
- Yaskawa AFD Selection Guide
- Yaskawa AFD Programming & Configuration
- Yaskawa AFD Troubleshooting
- Yaskawa AFD EtherNet/IP Communication
- Yaskawa AFD Modbus Communication
- Yaskawa AFD Applications
- Yaskawa AFD vs Allen-Bradley PowerFlex
- Yaskawa AFD Installation & Wiring
- Yaskawa AFD Maintenance
These articles offer additional technical insights into the automation, networking, monitoring, and control technologies that support modern industrial automation and mission-critical infrastructure.
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