How to size a VFD

Having trouble finding the right VFD for your job? Call 800-800-2261 to talk to a sales engineer!

Our VP of engineer Craig Hartman will walk you through how to find a VFD based on your motor name plate in this short and sweet video.

[andrewng]

Sometimes the noise of the motor fed by a VFD can be objectionable, then we gotta increase the switching frequency but it comes with a derating.

[driveconstructor]

If someone would like to continue learning about VFDs and get some practice with sizing drive systems, try the DriveConstructor online course

[Ray-tuyf]

Application : Pump

Motor : 1HP 2Pole 3Ph 50Hz FLA 1.7a

Driver :
FLA - 0.7a to 3.0a (Default at 2.5a)

The input amp and output amp from drive rating when i run motor at
5hz - __ / 1.7a
25Hz - 0.3a / 1.7a
30Hz - 0.4a / 1.7a
50Hz - 1.7a / 2.5a

Kind regards

Ray

[dennisleazott]

Hi Craig . . . I would like to add a big red safety STOP mag switch with the VFD I am installing on a bandsaw (1.5hp / 220V 3P) to run off 220/1P. I can place it between the source and VFD or between the VFD and motor. Any recommendation on which method is best?
Thanks,
Dennis

[maaziftikhar]

I have a VFD drive thats running a 5.5 kW motor with solar power, it also has terminals for AC input. can I use a 7 KVA generator to run this motor? My purpose here is just to overcome the starting torque so that i dont have to buy a bigger generator?

[iacovacheiuliangheorghe]

Hello, I also have an SP81 miniaturung, it has a 0.37 kw / 380 motor and I want to put a converter on it to go to 220v. Could I put a converter of 1kw or more on it?

[freestyla]

Something I’ve never really found much information on is what type of 3 phase motor works or doesn’t work with a single phase VFD. Does the motor have to have a 240v configuration on the ID plate to be compatible? Would a 400 odd volt three phase work with a single phase vfd?

[abosafaakara]

Dear Sir
I have inverter 200 kw can I use it with motor 250 kw ?
Application :main motor for plastic extruder

[Ray-tuyf]

Hi Sir,

Can I use the VFD as below:-
1. Input - 415V 50HZ 8.3V/Ph
2 Output - 460V 60Hz 7.8V/Ph
3. For centrifugal pump

Does it affect the life span of motor or VFD.

Kind regards

Ray

[ryanramnath]

In the video he said all "VFD are constant T", if I am spinning a motor in a fluid would I have to set the T on the VFD before I start my process?

Kind regards

[seannot-telling]

Hope you can give me an answer. I have a compressor I want to run and may later up the size to a high rated one. Can I go over sized and not mess things up or?

[umeshmudgil]

can i run vfd by applying dc power to the brake terminal and switching off the 3phase input power

[vfieromatt]

Is there a drive that will do 480v single phase input to 3phase output?

[Ray-tuyf]

Hi Sir,
Can I use a VFD Drive (3.7kW) 8.2Amp on 4kW (7.5amp) Motor ?

Kind regards

Ray

[ianjemaryu]

hello, i have a question sir. i have a problem in my circuit breaker. it is installed after after a vfd drives and it always tripp when it runs for a few minutes even w/ a normal current. what does it cause to trip? thanks.... can you give me some idea why my breaker trips when installed after a vfd drive? thanks..

[ehsanbarati]

hi.can I use 3kw motor(i=11.4) with 3kw vfd(i=8.5)? thank you