Questions tagged [vfd]
Variable frequency drive, a three-phase AC output motor controller. Questions about vacuum fluorescent displays should not receive this tag.
135
questions
0
votes
1answer
29 views
Does a load reactor eliminate the need for EMC cabling?
The company I work with installs ventilators driven by VFD's. To save on cost of EMC cabling we use load reactors at the VFD outputs. (Other considerations for not using EMC cabling have to do with ...
0
votes
0answers
35 views
VFD configured for six-step output instead of SPWM?
I need a transformerless inverter which generates a 3 phase 230 VAC modified sine wave output from 325 VDC input. Unfortunately, it seems these are rare, at least high power models. Can a VFD (with DC ...
0
votes
0answers
41 views
isolated 5v PWM to 0-10V
I'm trying to convert a 5V PWM signal to 0-10V through an optocoupler to drive a VFD.
The output "0-10V" should be 0V when PWM duty cycle is 0%, and 10V when 100% (linearly !).
Here is what I've come ...
0
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0answers
11 views
Variable speed conveyor / frequent stop and start [migrated]
I'm working on an application which requires varying the speed of a conveyor that will frequently need to stop and start.
More specifically, we need to first set the speed of the belt, and then have ...
0
votes
2answers
52 views
Parameters of the 3 phase geared induction motor
I have a 3 phase geared induction motor. The name plate is below image.
I couldn't find any datasheet from internet.
Explain me parameters that on nameplate for entering to VFD.
I need to know Rated ...
0
votes
1answer
51 views
Can I operate a 500kW/1500rpms motor at 35Hz with 400kW inverter?
In stock we have a 3 phase induction motor with a rated power 500kW and 1490rpms.
What is the smallest frequency inverter which we can use to operate this motor in a machine with a maximum power/...
1
vote
1answer
92 views
Variable Frequency Drive with AC motor, 30kW
I have a VFD that controls an AC motor which compresses air. It is an 30kW motor. I have set the parameters required to drive the motor and it runs the motor but not properly.
During the test the ...
1
vote
1answer
65 views
VFD as general use inverter
I'd like to have 3ph 208 in my house for general use (not a motor). If I run the output of a single phase to 3 phase VFD through inductors or a 1:1 transformer will it smooth the SPWM .output into an ...
0
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1answer
52 views
Termination of SY cable shield at VFD and 3 phase motor?
I am wiring a single to 3 phase VFD to a 3 phase motor (240V delta). The 3/4HP motor powers a lathe in a domestic setting. Supply voltage is 240V 50Hz.
As per the VFD instructions, I am using ...
1
vote
3answers
279 views
Braking Methods of Induction Motor in VFD
As you know, we can stop an induction motor by plugging or regenerative braking. What I'd like to know is that when controlling induction motor with VFD, which braking way VFD uses? It seems to me ...
1
vote
2answers
281 views
How to Size Line Reactors and Understanding Reactor Specifications
I've got a 600 VAC, 75 HP VFD that I want to place line and load reactors in series with. Usually, I find charts like this that give me a horsepower table to follow as they are the easiest to use. ...
0
votes
1answer
57 views
Vcc drops on connecting variable resistor between it and ground
I have a VFD with a control board I am trying to fix. It requires an external variable resistor to be connected between the +10V terminal, analog reference terminal and ground. I found that on ...
0
votes
2answers
53 views
How VFD affects an isolated IOT system
To avoid noise from the external system I tried to isolate the internal completely. So I added DC-DC isolated converter with signal isolation. I have attached the picture. Still when reading data and ...
0
votes
3answers
243 views
Can a Variable Frequency Drive convert standard wall outlet (120V/15A/single phase) to ~220V 3 phase?
In my workshop I have a device that requires 220V 3 phase power, with a requirement of up to 1.5kVA. In North America, my wall outlet provides ~120V/15A single phases.
(EDIT - my device can take +/- ...
1
vote
1answer
42 views
Slip Control vs Constant V/F Control for 3-Phase ACIM
I am trying to understand how is Slip Control different from Constant V/F control. If I need to control the speed of 3-phase ACIM then its slip would obviously change with its rotational speed then ...
0
votes
1answer
33 views
Speed control using direct torque control of induction motor
Is there any steady state error present in speed output at any load in direct torque control of induction motor?
1
vote
1answer
51 views
Voltage source & current input
I am working on a project where I have a current source (analog output from a PLC) controlling a VFD. Based on the position of the dipswitch, the VFD will accept either a current or voltage input. The ...
2
votes
1answer
127 views
Motor / VFD / Protective Earth
I have little experience with AC motors since I'm majoring in Mech.E. My team is setting up an AC motor with a VFD to control the movement of an airfoil inside a metal cage we built. I understand the ...
1
vote
1answer
62 views
Does a 3-phase VFD work if one phase is reduced (e.g. with a dimmer)?
If you have a 3-phase VFD running a 3-phase motor, and you use a leading or trailing edge dimmer on one or two of the input phases, will the VFD continue to operate normally, pulling more current from ...
3
votes
2answers
171 views
Miscalculating the nominal power using nominal current and voltage of a VFD
A variable frequency drive datasheet has current parameters named as I2N and I2hd. If Im not mistaken these currents are the per line currents for the drive output as follows where I showed in red ...
1
vote
3answers
228 views
A very basic question about VFD output frequency
I know that a VFD's inverter stage creates alternating voltages at a desired frequency for the terminals of a delta induction motor(stator voltage freq.).
Normally without a VFD the nominal freq. ...
0
votes
1answer
220 views
operating a motor with a undersized vfd
A centrifugal pump requires 21.6 hp to flow 350 gpm at 2800 rpm with a 230/460V, 40 hp, 2-pole (3600 rpm) motor. The VFD available can operate up to a 25 hp motor at 230V, with a maximum output of 68 ...
1
vote
1answer
39 views
DC bus correction for inverter VFD via PWM modulation
This is a question concerning an inverter circuit without PFC.
Single phase AC is rectified and pooled on DC bus capacitors.
From there the DC voltage is modulated at 5kHz on 6 IGBTs, emulating ...
1
vote
1answer
70 views
Why use many-pole motor for high speed?
I found in this teardown analysis of the Nissan Leaf drive motor that it runs up to about 10,000 RPM but is an 8-pole motor. My understanding is that the inverter cost goes up with frequency. The Leaf ...
2
votes
2answers
263 views
Powering a 3 Phase 230VAC Motor with 28 12V Batteries wired in Series
Mechanical Engineering student here. I'm a part of a senior project team that trying to run a 40 HP 230 VAC three phase motor with a 40 HP VFD for a hydraulic pump. Our plan is to wire 28 Lead Acid ...
1
vote
1answer
118 views
Problem in temperature transmitter because of VFD (Variable Frequency Drive)
I made an amplifier of PT100 bridge which operates on 24V DC supply and gives 0 - 10V DC for 0 - 400°C when tuned. The circuit is as follows :
Here P2 + and P4 S+ are shorted and P4 S- is left open....
1
vote
2answers
135 views
Not using all 3 phases of sine filter
I want to run a single phase motor with a single phase VFD.
I don't believe that the motor is rated to run with a VFD. To compensate for the issue I would like to use a sine wave filter. ...
0
votes
0answers
43 views
PWM for ACIM scalar control
I have inherited a control software for ACIM scalar control and I need to do some changes in this software. Before I can do any change I need to understand current implementation. So I have started to ...
1
vote
1answer
112 views
Inductor Machines: why is constant flux achieved before reaching nominal speed?
It is observed that an induction machine increases its voltage linearly before reaching its nominal speed. This is achieved due to the emf generated by the rotor movement.
However, I find it ...
0
votes
0answers
48 views
There exists 110v/60Hz motors as well 220/50Hz ac motors rating, what determines the voltage of an electric motor?
I have seen the Toms question and answers for what determines the voltage of an electric motor? None of the answers not fulfilling. I was not able to comment to get clarify my doubt, so I’m posting ...
2
votes
2answers
69 views
AC motor must be run off inverted DC?
I am looking at the datasheet for a motor. This is an AC induction motor designed for use in electric vehicles. It includes the statement [my emphasis]:
The motors are designed for installation in ...
0
votes
2answers
95 views
PMSM control method
Is it possible to apply the so called scalar control or V/f control which is
used for ACIM control also for PMSM control?
I think no because of V/f control
used for ACIM does not know current ...
1
vote
2answers
193 views
Run 1800 RPM motor at 3600 RPM
I have a 2”x72” belt grinder with a Brook Crompton bf4n.75-2 motor.
It is connected to a Teco L510 VFD. Running here in the United States on 110v. My question is about turning up the RPMs sometimes ...
0
votes
1answer
251 views
Wiring a 2 pole three-phase DB motor to a VFD
Hello everyone this is my first time posting here so forgive me if my post seems a little choppy. So my dilemma is trying to hook up a 2 pole three-phase DB motor rated at 230 X 3. I did a fair amount ...
0
votes
1answer
61 views
How do you set up a VFD to run a motor at 2 different speeds?
I'm already familiar with the concept of altering the frequency to change the speed of the motor. So in this scenario, I'm looking into running a pump at 40Hz (high speed) and 23Hz (low speed). This ...
0
votes
2answers
133 views
Replacing an old 2 speed rotary cam switch with VFD
I bought an old drill press tnw super condor 30l but the motor smoked because of the rotary cam switch is broken.
The drill is old and the motor have no motor plate but few engraved numbers 380 and 20 ...
0
votes
1answer
79 views
What actually kicks in a VFD?
I am just getting into the plant environment and the first thing I noticed is that virtually all the motors are controlled by VFDs.
I understand that your supply goes into your RST terminals and the ...
0
votes
1answer
182 views
Output voltage of 3-phase in / 3-phase out inverter
I am using UK mains (230 V phase, 400 V line) to drive a Japanese motor expecting 115 V phase, 200 V line), presently using 2:1 transformers. I would like to control speed between 30 and 70 Hz, ie +/- ...
1
vote
2answers
73 views
How much is the permeability of this attached inductor core?
I want to use this inductor for AC line filter as line reactor. Its inductance value is 6 mH but I don't know the exact value of permeability of the material. It will be used with VFD at the input to ...
0
votes
1answer
78 views
how to design AC line filter for VFD?
I am working on VFD for single phase induction motor. I am rectifying AC 220V directly to DC link capacitor. There is no LC filter from AC mains. There are harmonics in the AC mains. Can you suggest ...
0
votes
1answer
46 views
Polyphase motor with VFD
I purchased a dayton 1/3 hp 1725rpm and am wondering how to use it with a VFD. It says continuious as duty. I only have 220 at my house so I am wondering if i can set it up with a VFD and use it to ...
0
votes
1answer
192 views
Can VFD be used with induction motor for regeneration?
I want to use VFD with induction motor to run it as induction generator (driven by external prime mover). Does VFD circuit allow reverse flow of electrical power?
Thanks
0
votes
1answer
162 views
Why even when we increase the synchronous speed, the slip still remains it's value? [closed]
This is an induction motor question: why even when we increase the synchronous speed, the slip still remains it's value?
1
vote
3answers
379 views
Using PWM instead of real DC for VFD's 0-10V control input
There is a VFD which controls an AC motor through a 0-10V control. I know that this control voltage is DC voltage.
I'm wondering would a PWM work for this application? I mean instead of 2VDC, what ...
-2
votes
1answer
60 views
Programming LS-iG5A
I have got this LS iG5A VFD to control speed of my
rotary cutter machine. I have attached a momentary
On/Off switch to start stop the motor and also
connected a 10k POT to control its speed
My ...
1
vote
1answer
2k views
How does carrier frequency and pulse width modulation in a VFD work together to control AC motor speed?
There is a lot of online information about this but there is also a lot of contradictory information. What is carrier frequency exactly and does it stay the same or does it vary? I understand the ...
0
votes
1answer
168 views
Mega2560 master on RS485 bus stops communicating with VFD when I add another RS485 module
I’m doing a project where I’m building a control panel for a VFD (inverter/variable frequency drive). I’m connecting the two over half duplex RS485 and use Modbus RTU. As a master I use a Arduino Mega ...
0
votes
2answers
187 views
What is the recommended way for starting an ac induction motor with a VFD?
I am designing a control strategy for an AC(induction) 3-phase motor fan in an HVAC air handling unit for pressure control inside the ductwork.
The plan is to use a PID algorithm for the pressure ...
0
votes
1answer
656 views
Earth leakage tripping with 3 phase motor [closed]
I'm working in elevator world, i'm now in a strange situation.
The 3 Phase synchronous motor is connected by drive then main controller and a distribution board.
The faulty earth leakage circuit ...
0
votes
2answers
2k views
How to measure output voltage and current of a VFD?
Is it possible to measure the output of a Variable Frequency Drive without relying on it's display data? I tried to measure the line voltage with a DMM and current with a clamp meter but it shows ...
