Vector AC Drive | Marshall Wolf Automation

TECO AC Drive Question

Wednesday, May 15, 2013
by Scott Welch

Question:

I have a Teco JNEV-203-H1 variable frequency drive that I just received. When enabled, it will run up and oscillate between 5-6 hertz. After I disable then re-enable and off we go and will run up to speed.

Answer:

This depends on the motor that is being used. We have seen this before with other vendors motors. Because the drive is defaulted in sensorless vector mode and the algorithms are pre-set for TECO motors, the units sometimes get "confused" by other motors in sensorless vector mode.

You should convert from Sensorless Vector to V/f

1. Set parameter F51 to 1 to access C parameters. Then Press the function button to get the C menu.

2. Set C14 = 001, and the problem should disappear.

Marshall Wolf Automation can help you with your variable frequency drive applications!

What Is Vector Control?

Thursday, May 9, 2013
by Beckie Bordenaro

I started my search by checking out Wikipedia. I then looked up and read a number of things to come up with my very own simplified explanation. Disclaimer: I am in no way an engineer! This topic gets pretty deep, pretty fast. I'll do my best to keep it basic.

Vector control drives basically control 3-phase AC electric motor output by using two variables; voltage magnitude and frequency. We'll go just a little bit deeper to explain that vector control is available as field oriented control (FOC) or sensorless.

Most variable frequency drives used are Volts/Hertz, which means they provide open-loop operation. These drives are unable to retrieve feedback from the process, but can generally do the job for most applications. If these drives are not accurate enough then you want to take a look at vector control.

In general, if your application requires higher levels of accuracy, vector may be the way to go. These high performance AC drives can adjust themselves to sustain the programmed speed, rate, torque, and/or position.

Marshall Wolf Automation is a variably frequency drive powerhouse! We have a large inventory ready to ship, competitive pricing and we are authorized for all the top brands. Did I mention complimentary tech support?

View all of our AC drives now!

AC Tech Drives Sales Milestone!

Wednesday, May 8, 2013
by Beckie Bordenaro

Marshall Wolf Automation has reached $1 million dollar in sales for Lenze AC Tech's fiscal year.

Lenze AC Tech is a key product line for Marshall Wolf Automation and we are very excited to announce this milestone

Marshall Wolf Automation is your authorized stocking distributor for AC Tech variable frequency drives. Our inside sales and technical support staff can quickly assist you in finding the best high performance AC drive for your application.

Thank you to all of our customers that helped us reach this goal!

Tech Question Regarding AC Tech Lenze SMVector Drives

Monday, May 6, 2013
by Scott Welch

Question:

I took your advice and downloaded the operator's manual for the Lenze AC Tech SM vector drive and have read through it a couple of times. I have a couple of concerns:

# 1- I have some worry about the admonition about starting the drive into a coasting motor. In our application it should not be a big problem but there's always a chance that the operator could give a "stop" command, change his/her mind and immediately give a "run" command while the motor was still coasting down.

If I understand the manual, if we set the controller to stop with DC braking, the motor will not restart until it has come to a stop. That is, a "run" command would be ignored until the motor had stopped. Is that a correct interpretation?

#2 - Second, for the motor parameters required for torque limiting in vector torque mode, the stator resistance and stator inductance could be measured directly but the manual seems to suggest that those parameters would also be calculated by the controller during set-up, depending on how P399 is set. Am I interpreting this correctly?

Answers:

#1 The drive will not start if the DC brake is active; but keep in mind, if the drive is set up for coast with a DC brake, the moment the drive sees a stop command the DC brake will engage. So, the motor will have a DC voltage applied and will probably still be spinning, you can do that, but it’s not good for all applications.

#2 As far as the stator resistance and inductance go. Those values are actually measured by the drive during the calibration for vector mode. So typically after entering 306-306, set 399 to standard calibration and apply a start command.

Send your questions in! Marshall Wolf Automation offers in-house technical support for all of our products.

Categorizing Products!

Monday, May 6, 2013
by Beckie Bordenaro

We have been spending some time recategorizing our inventory. This sounds simple, however, it is anything but!

It's amazing the number of products that we all use multiple names for. AC drives are called variable frequency drives, inverters, motor speed controllers and many other names.

Stack lights are light towers are tower lights are warning lights.

How does one categorize wire, wire duct, terminal blocks, DIN rail and the many accessories these items use? I've seen 'wiring solutions' as a nice category and I've also seen every product separated out individually.

I consider a heater... a heater. An electric heater. Apparently it's common for some to call an overload relay a heater... who knew?

Servo motors - under motors or in a motion control category? Gearmotors, are they motors or should they have their own category?

How vague can we make switches? Should it include pushbuttons, e-stops and pressure switches? Would you think to look under 'switch' for a pushbutton?

Relays is another crazy one. Should mercury relays be lumped in with solid state relays? What about SmartRelays? I ended up putting those with PLC's (which brings me to the insane category of controllers...).

This concludes my mini-rant regarding product categories... thanks for reading! Your feedback is always appreciated - beckie@wolfautomation.com.

Student Looking For A Variable Frequency Drive Recommendation

Tuesday, April 30, 2013
by Scott Welch

Question:

I am a Ph.D. student working in the Department of Mechanical Engineering in the University of British Columbia.

I have a blower with a 230/460 Volts AC, Three Phase (17.4/8.7 Amps), 7.5 hp motor.

I am looking for a variable frequency drive for this blower to change the motor speed and so blower flow rate.

Please provide me with your suggestions for appropriate VFD for described motor that suit my technical requirements.

I look forward to hearing from you soon.

Answer:

Take a look at the AC Tech SM Vector variable frequency drive. Below I have quoted both the 230 and 460 volt input versions as I did not know the input voltage and the motor can run off either.

ESV552N02TXB AC Tech 7.5 HP Nema 1 230 volt input $441.10 or ESV552N04TXB AC Tech 7.5 HP Nema 1 460 volt input $438.90

Marshall Wolf Automation is your authorized AC Tech Lenze distributor for their complete line of high performance AC drives.Whic

Variable Frequency Drives

Friday, April 26, 2013
by Caryl Clement

Variable frequency inverters are used for electronic speed control of AC induction motors. The needs of the market are wide and varied, and AC Tech Lenze offers a broad range of standard products for everything from simple speed control to complex; each with a wide range of functionality, small physical size and exceptional performance.

Their drives are reliable, flexible to apply, easy to commission, and meet the highest standards of quality. AC Tech Lenze provides solutions to fulfill nearly any inverter requirement in the power range between 0.25 and 400 kW.

Standard Enclosure

NEMA 1 (IP31)
120V - 600V
0.33 to 60HP ( 0.25 - 45kW)
Open-loop Vector, V/Hz

SCM and SCL Series

0.33 to 15HP (0.25 to 11kW)
IP20
120V - 480V
V/Hz

MCH Series

200-590V
1.0 to 250 Hp (0.75-185kW)
NEMA 1 (IP31), NEMA 4(X) (IP65), NEMA 12 (IP54)
V/Hz

Contact Marshall Wolf Automation for all of your inverter needs. With extended hours to serve you better, technical help on staff and friendly customer service representatives, we are here to help you! 800-325-9653

AC Tech/Lenze Products

Friday, April 26, 2013
by Caryl Clement

Marshall Wolf Automation, your industrial automation distributor for all things that keep your business running has all of the AC Tech/Lenze products you need.

The general purpose variable frequency drives in the SCM/SM series (IP 20 and up to 15hp) are ready to use right out of the box - simple to program and easy to install. Available in single or 3 phase input

If you need a general purpose drive with modbus, the SCF/SF series is perfect! The same as our SCM Series - with these added features:Analog outputs of speed and load and modbus communication and optional high output frequency!

How about a NEMA 4X indoor duty vector drive? The SM Vector drives can handle that. And for an outside version of that same drive, click here. NEMA 4X rated for indoor or outdoor use and available in standard or filtered input. Now up to 30hp!

We've got you covered in an HVAC-oriented drive as well. The variable torque MCH series is available in up to 250hp! We can provide the drive with standard options such as input disconnect and fusing, line reactor, 3-contactor bypass and more enclosed and mounted to the drive in a ready to install package.

Call us today at 800-325-9653 (WOLF)

Tech Question Regarding A Tensioning Application

Friday, April 26, 2013
by Scott Welch

Question:

I'm doing some engineering work for a small company here in North Carolina. The project involves making a textile winder which ideally would maintain constant fabric tension while a spool is filled. Just an FYI, the spool diameter varies from 3.25" diameter to 10.5" diameter. Desired fabric tension is around 5 lbs and the textile speed is around 3' per minute.

In the past, they've used a small DC gearmotor running at constant speed, along with a mechanical a slipper clutch to take care of the speed differential. The system works....sort of, but the tension is never really correct because of the varying diameter and the speed is correct only because of the slipper clutch.

I thought that perhaps we could accomplish the same thing with a 3-phase gear motor under VFD control. We have quite a bit of experience with the ACTech VFD controller and we could control speed using that device's 0-10 Volt signal input along with a sensor to detect how full the spool had become. However, the AC Tech unit does not offer any control parameters which can limit motor torque.

So after all this preamble, my question is, are there other variable frequency drives which do have motor torque control parameters available? The power requirements for this winder are quite low, certainly less than 1/10th horsepower so for almost any conceivable 3 phase motor, the torque limitation would have to be down in the range of, say, 10% to 20% of the full load capability of the motor. Is this feasible or should we stick with the slipper clutch?

I know there are many much more sophisticated winder tension control systems available but almost all of them would be "overkill" for this project.

Answer:

Take a look at the Vector Control Mode on the AC Tech SM Vector series of high performance AC drives. The SMVector does have a parameter that can limit the % torque limit of the motor using P330 or a preset torque set point using P331-333. Keep in mind that these parameters are only active in Vector Torque mode(P300:05). In Vector torque mode the torque is controlled independent of speed. Also, Vector mode does not work correctly if P302/303/304/305/306 are not set according to motor data.

AC Tech EEPM1RA Programmer, Duplicate a Drive Program in 2 Seconds

Thursday, April 25, 2013
by Jim Frazzetto

Duplicate a drive program in 2 seconds with the touch of a button! Easily archive programs to a PC, perform job changes without repgramming and save default parameters for the OEM's machine.

Simply plug and EPM into the AC Tech EPM programmer and press 'Transfer to EPM'. In 2 seconds the EPM is ready to be installed!

Holds up to 30 prgram files and by using the Tech-Link software (available FREE online in AC Tech's Technical Library section) and a standard RS-232 cable you can archive programs to your PLC!

This product is an accessory for the following products: