VFD Inverters/AC Drives FAQs

Learn More About Our Drives Solutions and Applications
Simply select the subject area below to obtain answers to some of your most frequently asked questions.

What type of analog signals can I use for a speed reference?
When should I use source and when should I use sink?
I have an old Fuji Electric/GE AF-300 drive; can that be cross referenced to a current Fuji Electric Drive?
What is the difference between the Variable Torque and the Constant Torque rating on the FRENIC-MEGA?
What is the most important thing to consider when selecting a drive for a motor?
I would like to know where to purchase a drive or replace an older FRENIC model; who should I contact? 
What control methods are available?
Do Fuji Electric FRENIC Drives have PID capabilities?
Can I set the drive to follow a remote run command?
Does Fuji Electric offer support documentation and application notes to get me started?
What parameters should I set when installing a drive?
Can I use single phase power?
If I need help setting my drive up for the first time or am having issues with, what kind of support do you offer? 
Do you have authorized service providers?

What type of analog signals can I use for a speed reference?
0-10VDC or 4-20mA
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When should I use source and when should I use sink?
Use sink when using dry contacts for control of the digital inputs. Use source when using a 24V <50mA source for control of the digital inputs.
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I have an old Fuji Electric/GE AF-300 drive; can that be cross referenced to a current Fuji Electric Drive?
Yes! We offer a modern replacements for the AF-300 series as well as legacy Fuji Drives. Just contact your distributor, sales rep or us directly (americas.fujielectric.com/contact-us/) with the information you have available on the drive you wish to replace and we will be glad to work with you to find the best solution.
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What is the difference between the Variable Torque and the Constant Torque rating on the FRENIC-MEGA?
The FRENIC-MEGA is a dual rated drive meaning that it is has a different HP, Current and overload rating depending on if you select High Duty or Low Duty. The HP rating given in the type number is for Variable torque. On 10HP and above you need to go up 1 size for constant torque. Example for a 20HP, 28 AMP 460 V, constant torque application you would use an FRN025G1S-4U. For a variable torque application with the same specifications you would use an FRN020G1S-4U.

Variable torque reduces the torque in a proportion of the square of the speed. Constant Torque uses a linear relationship of torque and speed.  Variable torque is used in fan and pump application. The overload rating for variable torque is 120% for 60 seconds. Constant torque has an overload rating of 150% for 60 seconds and 200% for 3 seconds.

On loads such as a fan little torque is needed at lower speeds, as the speed increases so does the force of the air. This creates a demand for greater torque at higher speeds and lower torque at lesser speeds. Because Variable torque uses less torque at lower speeds it adds to savings on cost.

Constant torque is ideal when the torque must be the same across the entire speed range. A conveyor is a good example to use. On a conveyor you may be moving the same amount of weight at varying speeds. You will need the percent of torque to move it at a low speed as a higher speed.
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What is the most important thing to consider when selecting a drive for a motor?
Current and Voltage! You cannot always rely on the HP or KW value, some motors have special characteristics that greatly change the amount of current that it draws. You should ALWAYS make sure the output voltage range of the drive meets the input voltage rating of the motor, and that the FLA of the motor is less than or equal to the drive’s output current rating.
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I would like to know where to purchase a drive or replace an older model; who should I contact?
Click the Find Sales Rep/Distributor option at the top of our webpage (americas.fujielectric.com/find-a-sales-rep/). From there select Drives & Inverters from the Business Unit menu and Select your state from the Country/State. From there you pick a Sales Rep or Distributor close to your location or contact the Fuji Electric Regional Sales Manager for more assistance.
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What control methods are available?
All drives offer volts/hertz standard. The FRENIC-MEGA and Multi offer Dynamic Torque Vector control standard; Volts/Hertz with encoder and Dynamic Torque Vector Control with encoder are available with an option card. The FRENIC-MEGA also offers Sensor less Vector control standard and Vector Control with Encoder with an option card.
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Do Fuji Electric FRENIC Drives have PID capabilities?
Yes! We offer Application notes for using a 4-20 mA pressure transducer on our webpage americas.fujielectric.com/products/drives/
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Can I set the drive to follow a remote run command?
Yes! Land the wires for your remote run signal on FWD and CM and set function code F02 to 1.
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Does Fuji Electric offer support documentation and application notes to get me started?
Yes! If you click on the tab for drive you are using americas.fujielectric.com/products/drives/ you can find application notes, manuals, specification sheets and more.
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What parameters should I set when installing a drive?
You should set all of your motor data; Base Frequency (F04), Rated Voltage (F05), Overload protection (F11 & F12), Motor poles (P01 not offered on the mini), Motor HP (P02) and Motor Amps (P03).

Our FRENIC-Multi, Eco and MEGA offer a quick set menu for all of the key settings. For additional information the Instruction manuals for each of our drives are available for download at americas.fujielectric.com/products/drives/.
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Can I use single phase power?
Because the drive controls the motor with PMW you can supply single-phase input power to the drive and run a 3-phase motor. You must be running a 3-phase motor our drive is NOT designed to run single-phase motors. When using a drive rated for 3-phase power a larger capacity drive is required when using single-phase input power. In the preface chapter of all of our manuals you can find UL tested rating for our drives when using single-phase input power. We also offer smaller HP versions of the Multi and Mini already rated for single-phase input power.
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If I need help setting my drive up for the first time or am having issues with, what kind of support do you offer? 
We offer free, fast and friendly Tech support from 9am (EST) Monday morning through 11:59 PM (PST) Friday

Call 510-403-7866 ext. 1: M-F 6AM-5PM

Call 1-888-900-3854 M-F for after-hours emergencies.
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Do you have authorized service providers?
Yes! We have our in house service team that will help you with Service parts, RMA/Warranty Claims, onsite service and more.

510-403-7866 ext. 2

We also have authorized service companies across the country americas.fujielectric.com/products/drives/ac-drives-service-centers/
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