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General questions about a VFD for a 1-1/2 Bridgeport

Randalthor

Cast Iron
Joined
Mar 7, 2018
Location
Kansas City
I have looked through threads and haven't found the answers to these questions (although I'm sure they are on the forum somewhere).

I need a VFD to convert 1-phase to 3-phase for the vari-speed mill above. I don't care about features, but do care about longevity. I don't want to spend more than $400. I'd rather not go with an RPC because of added noise.

I've read the better brands like Weg, Hitachi, Yaskawa, Eaton??? give a better service life than cheap ones, capacitors being the weak link.

My question is, is there spec the manufacturer may publish, which indicates how long their capacitors will last? If you oversize the VFD for the application (i.e. get a 3 hp VFD for a 1-1/2 motor) will that give you a larger "capacitor bank" or use up the "bank" less quickly?

Lastly, I've read VFD's have the potential to send harmonics upstream. I don't want to destroy any electronics upstream. I think I've read there is some kind of device to prevent that, or does that only occur with cheap VFD's? Can someone clarify please?

I'd rather avoid an RPC because of the added noise.
 
Some VFDs have hour meter for things like fans and capacitors "Capacitor life warning signal- The inverter checks the operating life of the capacitors on the internal circuit board on the basis of the internal temperature and cumulative power on". So for an example if the WJ200 VFD was on 24 hours a day at 80% continuous load at 50C the capacitors would be rated for 5 years. Most likely under your operating conditions you are looking at 10-15+ years service life. The MTBF for the Yaskawa V1000 drives is something like 28 years. I do not think it will make a difference at the end of the day, and the smaller VFDs the capacitors are not readily replaceable. If/When they fail, it would probably be more cost effective to just replace it. Up-sizing the VFD may have a marginal effect on component lifespan. I would go with a 2Hp VFD (assuming single phase in), the least expensive would be something like the Teco L510-202-H1-U or F510-2002-C-U, Hitachi WJ200-015SF, Yaskawa CIMR-VUBA0010FAA. They will all work well and you only need basic functions for your mill. I would not worry about harmonics upstream in this application and you do not have a long motor cable. Since it is an older motor that is probably not VFD rated, I would just keep the VFD carrier frequency in the lower range, something like 5-8kHz. There are no electronics upstream, the VFD is directly connected to your motor, not electronics.
 
spec the manufacturer may publish, which indicates how long their capacitors will last?

The "good guys" at the least put a recommended replacement interval somewhere in their manual. Hard to find it, usually. Most would rather a "lasts forever" assumption was made, and too many buyers do exactly that.

Seven to nine years is not uncommon. As a "PREVENTIVE maintenance" figure? It is also conservative. Usually. Or so we may hope.

Otherwise, "what he said" covers it well.

Oh- Yaskawa/Magnetek may not seem as "famous" a brand as Hitachi & c. But they do have a long history of making durable and economical DC and AC drives. Many of them were once sold under other people's brand-labels. "Bigger" brands, usually.

Don't rule them out on "never heard of" grounds just because they do not also have their name on disk drives, laptops, telephone systems, kitchen appliances, and nuclear power plant goods.

Ability to deliver a ONE THOUSAND HP VFD from proven and tested stock plans, even if it ain't exactly kept sitting on shelves ten units deep is a resource set to be respected.

:)
 
Lastly, I've read VFD's have the potential to send harmonics upstream. I don't want to destroy any electronics upstream. I think I've read there is some kind of device to prevent that, or does that only occur with cheap VFD's? Can someone clarify please?

I'd rather avoid an RPC because of the added noise.

Any time-varying function can be expressed as a summation of harmonic components. Fourier transform theory and that kind of stuff can be found in a book like:

Pulse Width Modulation For Power Converters, Principles and Practice.
D. Grahame Holmes
Thomas A. Lipo

It will blow you away. I've been blown away many times. It has elevated my awareness of quality.

As regards to capacitors. Two of my AB drives have detachable circuit boards with four 560 uF filter capacitors. The caps can easily be replaced but I think the idea was to replace the board. A 7.5Hp drive with 3 fans, two blowing air across the main heat sink fins and one fan blowing air across the caps and driver board.
 
The caps can easily be replaced but I think the idea was to replace the board.

That board WAS a replacement.

Age of the drives you favour, immediately preceding rev level still had a flash boiler and triple expansion "steam up-and-down" output side for 3-Phase emulation.

Only "spikes" it generated were in the resident Operating Engineer's blood pressure levels when the shift change steam whistle rudely interrupted his nap.

You shall have to modernize at some point. Age of consent passes, they've the legal right to let the magic smoke out any time and place they see fit.
 
Thanks for the really helpful replies. Really great, especially the specific recommendations of model numbers - CIMR-VUBA0010FAA, WJ200-015SF, etc. Experts don't understand, but that's the kind of stuff very helpful to laymen like me.

One other question please (or three):

Is there any reason not to run a VFD on a cord?

In other words, I have a 240v 1-phase cabinet saw I run off a pigtail with a cord (not a long distance, about 25' - #12 wire) on a 20a circuit. It would be really simple (wire wise) to simply wire a little pigtail off the VFD for the mill, so that when I use the mill I use the same cord as I use for the table saw (obviously not running them both at the same time).

Put another way, I'd like to avoid running some type of dedicated outlet for the mill and just use the same outlet I use for my table saw (with the same cord, as both machines aren't close to the 240v outlet). I don't foresee any problem with this, but wanted to run it by the knowledgeable/clever folks here.

Lastly, there is a thread here

http://www.practicalmachinist.com/v...nd-vfd/setting-up-bridgeport-mill-vfd-343149/

in which B-Mathews recommends this VFD KBAC-27D 2HP VFD 115/23VAC GFCI 9667 He was somewhat flamed for his recommendation, but the rec caught my attention. He said he had put hundreds of units in, which seemed a big plus to me. But what I really liked was the water proof enclosure. This seemed advantageous to me in that it's also dust proof, more sound proof, and more plug and play (no need to buy a separate enclosure). Again features aren't a big deal to me, so lack of features on this unit are not a disadvantage to me. It's also advertised as analog, which makes me wonder if it's simpler (another advantage, as I don't use 90% of the features on my cell phone, TV, microwave, etc.)

Not challenging any of the recommendations here, which again I think are really great (and am just about ready to pull the trigger on) but just trying to bounce a few more thoughts off those more knowledgeable.
 
I often run VFDs using dedicated plugs, i.e separate plugs for each machine. I would not hardwired both machines to the same power cable if that is what you mean. You could use the main power as an extension cord with a box with separate plugs for each machine.

I have used a number of KB Electronics VFDs, some got replaced with more capable "programmable" VFDs. Their sealed units can get pricey, but they are often used for dusty environments like grinders. In some cases their simpler features are more of a problem, so like adding a braking resistor requires using their braking module, or expansion card at significant cost. VFDs can be placed in a sealed enclosure of sufficient volume, so it is sealed in a manner of speaking.

I would stand on my VFD recommendations on the Teco, Hitachi or Yaskawa. I doubt you will be replacing the capacitors in any of these VFDs, if you look at most small (2-5Hp) lathe and mills with factory VFDs, they predominately use Yaskawa VFDs so that tells you something about their durability. There are some aftermarket replacement VFD systems for the Bridgeport and they use the Hitachi WJ200. The Teco is probably the simplest to set up and is the least expensive, the Hitachi and Yaskawa are the next tier up in longevity/durability. There are lots of good VFD drives, so these are a few recommended models. We all have our preferences which are different.
 
Thanks again mksj for the very helpful comments and specifically on the commenting about the KB controls.

I think I'll go with either the Yaskawa or Hitachi, as you advised. Probably the Yaskawa since they show a 28 year mtbf vs. a ten year design life I saw advertised for the Hitachi WJ200.

The Yaskawa drives are expensive though. Perusing the internet, the only one I found which listed a price was from Galco for $415. Whew, that's hefty $$$ for a power supply for my little mill.

In terms of the enclosure to put the VFD in, I know these VFD's have cooling fans. Do you know what type of enclosure is best for the VFD? I'd be a little worried about putting the VFD in a totally enclosed box because of heat buildup. I've read on this forum many people use additional fans with filters to cool their VFDs on the box to put the VFD in, but I'd like to avoid that if possible because of more expense, more installation time, and noisier.
 
I have used the WJ200 for many years and hundreds of installs, and have yet to see one fail or be DOA. The component life is based on 24/7 use at 80-100% continuous load, so if you use your mill 8 hours a day every day that would equate to about 25-30 years expected MTBF. It is the primary VFD that I use for smaller installs, although the Yaskawa drives may be a bit better overall. Probably also on par with the ABB drives. The latter two VFDs may be better built, but I have also seen a lot of Teco L510 installed on Bridgeport mills without any issues, for those that want the least expensive and the easiest to install. As far as enclosures I would look at something in the 12-14 width, 14-16 height and 8" depth.Some examples below, a steel enclosure will have a bit better heat dissipation but any of these should work fine.
Hammond Manufacturing - N1J14128 - N1J Series Hinged NEMA 1 14x12x8 In Gray Steel Wallmount Box-Lid Enclosure - Allied Electronics & Automation
Hammond Manufacturing - EJ14128 - Eclipse Junior Hinged NEMA13 14x12x8 In Gray Steel Panel Mount Flanged Enclosure - Allied Electronics & Automation
New In Original Retail Box Stahlin Enclosures DS16148HPL | eBay

VFDs
Yaskawa CIMR-VUBA1FAA, 3 HP, 2-24V, VFD
CIMR-VUBA0010FAA - Yaskawa - AC Drives | Galco Industrial Electronics
https://www.driveswarehouse.com/WJ200-015SF-P21543.aspx
https://motorsandcontrol.com/produc...uency-drive-includes-advanced-digital-keypad/
 
The Yaskawa drives are expensive though. Perusing the internet, the only one I found which listed a price was from Galco for $415. Whew, that's hefty $$$ for a power supply for my little mill.
Not really. Compare it to TWO of "the other guys" over the next 10-20 years on the durability gain alone. Better ones, yet can be had. "Mission critical"? Well.. $1500-$2500 VFD are out there in that meagre power range, too. Big ones cost more than a motorcar. REALLY big ones cost more, yet.

In terms of the enclosure to put the VFD in, I know these VFD's have cooling fans. Do you know what type of enclosure is best for the VFD? I'd be a little worried about putting the VFD in a totally enclosed box because of heat buildup. I've read on this forum many people use additional fans with filters to cool their VFDs on the box to put the VFD in, but I'd like to avoid that if possible because of more expense, more installation time, and noisier.

Maker's manual TELLS YOU minimum supplementary enclosure sizes. They are LARGE. "Passive" heat transfer thing.

But forget "re-engineering " any VFD. Or an enclosure. You'll end up running in circles, and mostly useless ones.

You didn't really think the OEM's paid their Engineers and extensive test lab staff to just lay around watching porn videos, did you? Not their first rodeo. They've covered all this stuff. Cleaner is better, certainly. But they'll actually survive some downright outrageous filth - especially at your low-loading and infrequent use.

Just put it in a "clean enough as-is" area, run proper wire, clean the rocks, dog hair, mouse-turd and spider shit out of the fan/heatsink area once a year and let it earn its keep.

They are not as fragile as all that, or we would be burning them in BBQ grilles on You Tube for revenge-sport. Well - knowing how You Tube "works"? Some attention-seeking ass-hat probably already HAS DONE.

But odds are it is because he f****d-with a VFD instead of just RTFM, then USING it as-built.
 
If you are concerned with noise watch some youtube videos and listen to the "Motor Whine" that every VFD causes. It is basically the motor windings vibrating due to the pulse width modulation of the VFD. I've been trying to make my set up quiet with no real solutions that dosent cost a ton. I was graciously guided by members on this forum for making and installing filters and reactors. It worked to keep the motor quiet but then the filters that I installed made the noise at a higher level than when I didn't have any filters.
 
If you are concerned with noise watch some youtube videos and listen to the "Motor Whine" that every VFD causes. It is basically the motor windings vibrating due to the pulse width modulation of the VFD. I've been trying to make my set up quiet with no real solutions that dosent cost a ton. I was graciously guided by members on this forum for making and installing filters and reactors. It worked to keep the motor quiet but then the filters that I installed made the noise at a higher level than when I didn't have any filters.

Have to admit that my "Dinosaur Current" motors aren't dead-silent, either. Close enough to it I could blow raspberrys at the VFD-afflicted. Maybe. Sometimes.

But I will not.

Folks? To any of us as are going to actually make CHIPS with any of this stuff? Milling-machines most of all?

A bit of motor noise is... "down IN the noise", spectral distribution of energy wise.

Go Ogle "industrial hearing protection".

Act according to your needs.
 
Just wanted to try to finish out some comments about this thread. I ended up considering ABB, Yaskawa, and Hitachi. I called all three companies customer service departments.

All of them wanted to know my company name before they would talk to me (which signals to me they really don't want to talk to low level individuals like me, rather companies who are buying lots of units at a time (not judging here - an individual can tie up a whole lot of time in buying one unit at a time and taking more time than a business per unit) just offering an observation.)

ABB was the hardest to get through on customer service. Wanted basically your DNA profile to get through. Hitachi and Yaskawa were decent. I have my own small proprietorship company name so that probably helped. They all asked for a company name.

I was interested in how easy it was to access tech support, since I was buying a new component. I figure if part of the cost is tech support, I want to see how easy it is to access.

Hitachi was the friendliest guy. Yaskawa was the most who made me feel the smallest, like I was taking up his valuable time.

Of the three, I was most interested in the longevity of the unit, so that's what most of my focus was.

I asked them all about the MTBF. The Hitachi guy, who was the friendliest, gave me the most obscure answers, so I came to realize he really wasn't prepared to answer the question.

The ABB guy was very helpful in this regard and claimed the ABB units had a MTBF of 70+ years. This sounded very impressive at first, but he sent me a data sheet how they calculated the MTBF and I figured out it was totally bogus.

ABB takes the amount of units sold under the warranty period, times the length of time in service under the warranty period and extrapolates that out to the MTBF. In my mind this is a facade. The performance of new units under warranty has little to do with the projected longevity of units worn down by time. Here is the data sheet they sent me.

View attachment 228810

In the end, I looked at the archives of several sites (including PM) and found very few complaints about Yaskawa drives. When I called Galco, the rep said, based upon returns, he got less returns on Yaskawa than ABB. He clearly communicated to me in his opinion Yaskawa was the most reliable drive, so I ended up buying a Yaskawa.

Anyway, I'm unfamiliar with all of this, so I really don't know what I'm doing when it comes to VFDs, but thought I'd post my amateur experience.
 








 
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