Your favorite VFD.....

I'm specking out a new machine and looking at VFD's now to control a 480 VAC 1/2 HP induction motor. We have AB Powerflex 750 drives on some of our machines. However, I don't just want to go with that simply because that's the line we've always gone with. I want precision control with the best accuracy across the entire RPM range coupled with ease of use. If the AB 750 series is the one, then fine but if there is something better out there, then I want to look into it. I know the Powerflex 755 drive is pretty powerful with a gazillion parameters to tweak and mess with. Is there something out there with just as much or more capability but easier to use? Accuracy and precision control are first and foremost though. How about Honeywell VFD's? Anyone have experience with their Smart VFD's?

Thanks,
Don

Almost any VFD from a major supplier will give you good control. Ease of use is subjective. Most have competitive adjustment capabilities. If you need really tight control look at tach feedback or sensorless vector control.

More important are the quality of the VFD construction. (I personally avoid Siemens and GE, but many will disagree.) Also important is the level and quality of local support. Price matters, but you pay for the drive once, you pay for problems for years. Over the years I have had good luck with AB, ABB, and Eaton.

Honeywell VFDs are for HVAC use on pumps and fans, they are not intended for use on machine tool type applications and will not have the kind of precision features you are used to in the PF755.

The 755 is a top-of-the-line product, capable of controlling servo motors, which is an indicator of the high-end capability of the drive in terms of accuracy. So if you are comparing, make sure you are comparing other top end products. Also if you have a Rockwell Logix controller talking to that PF755 via Ethernet, you will not find anything else easier to implement in that arena.

If you are not, and the accuracy capability of the 755 is more than you really need, then you can consider going to a PF525 or even a 523 (no Ethernet). In general, the "Architecture" class drives like the 755 are capable of both Torque Vector Control and Velocity Vector Control. Lower levels of drives (Component Class like the 520 series and 40 series) typically do not offer Torque Control in the same way, i.e. they lack a dedicated torque regulator. If all you are wanting is accurate speed control using a velocity vector loop, you may be over killing it with a 755.

I like the little ABB ACS355 drives I started to replace obsolete 160 series with. They offer sensorless vector, a pretty easy to use keypad interface module and great performance. I did not find the manuals or support for the devicenet interface to be great, but the hardware was fine. I believe you can get an encoder interface for them if you need that level of precision.

I think you need to define what you mean by that ... "Accuracy and precision control are first and foremost though"

I would have a look at the new Altivar 32, a smart drive, with lots of features. It has an EthernetIP option if you need comms to an AB system. It also is only 45 mm wide and directly connects at the top to a standard MCB (Schneider GV series)
http://static.schneider-electric.us/docs/Motor Control/AC Drives/8800BR1001.pdf

We use Danfoss a lot. Little pricy but very reliable.

Coming from a long career in repair of VFD's, I would agree with the brands listed above to avoid.

As far as price, reliability, and ease of repair (which I can perform myself)...Baldor and A-B top my list. Baldor tops the list above all for support from a technical stand-point.

ABB purchased Baldor drives a couple years ago but I am still waiting to see how that pans out.

For ease of use, I like the A/D GS2 or GS3 drives. The GS2 uses volts per hertz control while the GS3 will use either volts per hertz or sensorless vector. The price isn't bad either. I've not had any issues with any of the ones I have installed, so reliability seems to be pretty good.

Agreed, Automation Direct has a lot of great equipment for really good prices.

We purchase a lot of equipment there for our I & E work.

We are using Automation Direct and AB 525. I really like the Ethernet comms with the 525 drive.

ABB is a great drive, never had issues.

Mitsubishi has a good reputation for reliability. If you're looking for something that's going to tie into the Allen-Bradley ecosystem it's hard to beat the Powerflex 525.

something to consider.

1. you already use ab drives and know how they work and you can program them.
2. why bring in a new drive that no one is familiar with?
there is a learning curve, programming and wiring issues to deal with along with training. Besides, you will be the one they call at 2 in the morning when the drive goes down, and you will be the one who has to answer for what took so long for the drive had to be replaced.
3. now you will have to keep the new brand of drive in inventory.

regards,
james

Any drive that starts with an 'A' followed by one or more 'B's.

I especially like the ABB ACS550 drives. However, if I'm connecting to a PLC and need more interface than start/stop/dir/speed then I'll drop a B from the brand specification in favor of the plug and play functionality.

Have used the new AB PF525's and was very impressed with the ease of use. Commissioning with the free Connected Components Workbench software was a breeze and the new V6 of this software is much improved over the original releases.

Also another vote for the ABB ACS355, have used many of these and although not as user friendly they are a solid drive. I have seen a few ABB failures though, although this may be due to one of my particular clients and the environment they are used in.

Danfoss VLT FC300 AutomationDrive series deserve a mention too. They have excellent HMI screens and are easy to use and have been very reliable from my experience.