VFD vs Staticv Phase converter

[fRED mCnEILL]

I just bought my son a used cabinet saw that has a 3hp 3 phase motor. My own cabinet saw also has a 3 phase motor and I have used a rotary phase converter for the past 15 years. At any rate I need a phase converter for his saw and was wondering about using a VFD. I know how a phase converter works(both static and rotary) but am unsure of the VFD. Does anyone use one for a table saw and can you reccomend a brand and how to determine the size needed.

Thanks


Fred,

[Rod Sheridan]

I use one for my wife's lathe, and my bandsaw mill.

You'll need one that will run a 3HP motor with a single phase input.

I happen to have a Baldor Industrial VFD, you can obtain other brands in the US for very little money............Rod.

[Matt Day]

I've had 4 VFD's so far, and need to order another for my Unisaw I just bought. They're simple to setup, small, and offer functions a RPC doesn't. Some functions like variable speed don't mean much on a TS, but you can have motor braking and soft start which is nice.

I'd recommend getting a TECO FM-50 from Factoration.

[Dan Friedrichs]

Teco makes a good VFD - you'd want something like this for a 3HP motor:
http://www.factorymation.com/FM50-203-C

There are also lots of "no name" ones available, such as this one (http://www.ebay.com/itm/3HP-2-2KW-7A-220VAC-SINGLE-PHASE-VARIABLE-FREQUENCY-DRIVE-INVERTER-VSD-VFD/130633905251?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%2 6asc%3D38530%26meid%3D6998ec2c6c5a4b7194a9daca93b3 0ac9%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D3611 55386082) on ebay. Most of these are all using the same IC and "transistor pack" (sourced from reputable manufacturers) and just adding their own user interfaces, enclosures, etc, so they aren't as "risky" as you might believe a no-name offshore-built piece of complicated electronics might be :)

As Matt says, a VFD is really nice. You can add a braking resistor to make the saw blade stop almost instantly (although you'd need to make sure it doesn't unscrew the arbor nut, in the process). There's no power consumption and no noise when idling (unlike an RPC). For a table saw, the speed control is probably not useful, but if you wanted to mount something like a sanding disk, that might be handy.

Nothing tricky about choosing one, either: you just need to pick one that supports a 3HP output on a single-phase input (which will certainly require 240V).

[Matt Day]

I had one of the 3hp eBay specials for $116 IIRC. My main complaint was the "instructions" were pitiful and it took many back and forth emails with the "support team" to get it working properly.

TECO's (~$200) are great for ease of setup and customer support.

[Eric Commarato]

I have a one VFD on a Clausing Drill Press and I love it because I can slow it down or speed it up. Last weekend my home built 7.5 HP Rotary Phase converter blew its idler motor. I purchased a new 10 HP unit from American Rotary. My largest motor is on my 5 HP Tannewitz table saw. The thing about a VFD is if you have a magnetic starter on your machine you will have to bi-pass it. Also you could use multiple machines on one VFD, but it gets wiring hairy. If you were going to have multiple three phase machines I would recommend the Rotary Phase Converter route. My old one served me well for 12 years, it was most likely just a bit underpowered for the Tanny. A rule of thumb for both VFD's and Rotary Phase coverters, you need to double the horsepower you are serving. For instance if you have a three horse power table saw, you will most likely need a 7.5 HP VFD to properly run it. If you have a 5 HP table saw like me, you will need a 10 HP Rotary Phase Converter to properly run it. You most likely know this since your already run a table saw off a RCP. I'd shy away from a Static, I think these just start the three phase motor so it can run on single phase providing only about 50-66% the horsepower of the motor.

Hope this helps.

[Matt Day]

I have a one VFD on a Clausing Drill Press and I love it because I can slow it down or speed it up. Last weekend my home built 7.5 HP Rotary Phase converter blew its idler motor. I purchased a new 10 HP unit from American Rotary. My largest motor is on my 5 HP Tannewitz table saw. The thing about a VFD is if you have a magnetic starter on your machine you will have to bi-pass it. Also you could use multiple machines on one VFD, but it gets wiring hairy. If you were going to have multiple three phase machines I would recommend the Rotary Phase Converter route. My old one served me well for 12 years, it was most likely just a bit underpowered for the Tanny. A rule of thumb for both VFD's and Rotary Phase coverters, you need to double the horsepower you are serving. For instance if you have a three horse power table saw, you will most likely need a 7.5 HP VFD to properly run it. If you have a 5 HP table saw like me, you will need a 10 HP Rotary Phase Converter to properly run it. You most likely know this since your already run a table saw off a RCP. I'd shy away from a Static, I think these just start the three phase motor so it can run on single phase providing only about 50-66% the horsepower of the motor.

Hope this helps.

That's not true for VFD's, at least up to 3HP. If you have a 3HP motor, get a 3hp VFD.

[Dan Friedrichs]

That's not true for VFD's, at least up to 3HP. If you have a 3HP motor, get a 3hp VFD.

+1. You don't need to oversize the VFD. Size it for the motor it is driving.

And, yes, the instructions for the ~$100 eBay VFDs are....lacking. But it's not terrible - certainly it can be figured out with some time and trial-and-error.

[Rich Riddle]

For smaller items, a TECO/Westinghouse works just fine. My friend, Bruce Norton, who does a LOT of things with VFD's will tell you that most are good but the more costly ones have a better sine wave (he's an engineer). He says for motors, the sine wave difference won't justify the difference in price on the best models because motors are far more forgiving than electronics. We had this conversation last night on the phone. He recommended considering the Hitachi VFD or the 7300 series of TECO/Westinghouse. While visiting Bruce in Tennessee on Sunday, I took a couple photos of a FEW of his tools on VFD's.

350934

[fRED mCnEILL]

" certainly it can be figured out with some time and trial-and-error."
LOL. 'Im always a bit concerned about trial and error with electrical stuff cause once you let the smoke out its REALLY hard to put it back.

[Matt Day]

'Im always a bit concerned about trial and error with electrical stuff

That's exactly why I think you should get a TECO FM-50. Excellent directions (I suggest you print them out full size, as a little booklet is supplied with the drive, see below), and excellent CS from Factorymation if you need it.

http://manuals.chudov.com/TECO-FM50-Manual.pdf

[Dan Friedrichs]

The nice thing is that most VFDs are very forgiving, in the sense that they have built-in protection for over-voltage, over-current, over-speed, etc. So there is low risk of blowing anything up. But they can also be onerous to set up, since they allow you to adjust all those protection settings (and a seemingly infinite number of other things), often through a rather overwhelming menu of parameters (eg - "Use the up/down arrows to navigate to parameter #b01-45, press the 'Enter' key, then use the up/down arrows to adjust the value of maximum motor speed, expressed in 'RPM divided by 10', or expressed in 'RPM divided by 100' if parameter #b02-34 is set to '1'")

I agree with Matt, though - the TECO is a much more user-friendly first VFD...

[Eric Commarato]

I'm just re-stating what a VFD salesman said to me...maybe he was trying to sell me a more expensive VFD...



+1. You don't need to oversize the VFD. Size it for the motor it is driving.

And, yes, the instructions for the ~$100 eBay VFDs are....lacking. But it's not terrible - certainly it can be figured out with some time and trial-and-error.

[Adam Herman]

I have a teco fm-50 on my drill press, very easy to set up and works great. I would recommend this route as well.

[Gaines Butman]

Sizing a VFD for phase conversion boils down to current (amps). When going from a single phase input to three phase out put you will need the drive to be capable of putting out 1.73 times the motor nameplate amps. You roughly de-rate the drive by half. I work in the electrical field and we routinely put VFDs on three phase irrigation motors where only single phase power is available. They do not work unless properly de-rated. I suppose one exception would be a motor that isn't under a load and therefore not pulling anywhere close to its nameplate amps. Once a load is applied the drive would likely trip/fault if not sized correctly.

[Matt Day]

Gaines,
My woodworking machines have all worked fine, and many hundreds of others have too. For instance, the motor in this application likely has an Amp rating of around 8, and the FM50 has an FLA of 10.5. The FLA need only be equal or higher than the motor plate amperage. The OP will be fine and does NOT need a 5hp VFD.

Pumps are different. Watch the video in the link below for a good overview.
http://www.vfds.com/blog/vfd-buying-guide

PS, I'm no expert, this is knoweledge I've gleaned from more knowledgeable folks than I.

[Van Huskey]

Gaines,
My woodworking machines have all worked fine, and many hundreds of others have too. For instance, the motor in this application likely has an Amp rating of around 8, and the FM50 has an FLA of 10.5. The FLA need only be equal or higher than the motor plate amperage. The OP will be fine and does NOT need a 5hp VFD.

Pumps are different. Watch the video in the link below for a good overview.
http://www.vfds.com/blog/vfd-buying-guide

PS, I'm no expert, this is knoweledge I've gleaned from more knowledgeable folks than I.


I agree, no de-rating for our machines. Whether larger or 24-7 motors need to have the VFD de-rated I don't know but as you said there are thousands of woodworking and metal working machines being run by ts hobbyists with no de-rating.

[Erik Manchester]

I have a 3 hp Unisaw that I ran on a Teco FM 50-203C without any issues, and it was handy for soft starts and deceleration. Don't want to set too rapid a deceleration as one could spin the arbor nut off. I think mine was set for 3 secs.

in my case, I had the VFD mounted on the shop wall some 15' from the saw with a start/stop station at the saw. You want to put the VFD in an enclosure with adequate ventilation but well clear of the sawdust being produced by the saw or other machines.

[fRED mCnEILL]

Given that my saw is 3HP would this VFD do the job.

https://www.amazon.com/LAPOND-Inverter-Professional-Frequency-VFD-2-2KW/dp/B01DKJWM6W/ref=sr_1_2?ie=UTF8&qid=1483770182&sr=8-2&keywords=LAPOND+VFD+DRIVE+VFD+Inverter

Thx

Fred

[Matt Day]

Looks like it would work fine. I haven't seen that one before but I might look into it for my Unisaw. Comes with a speed pot which is usually extra. Might be a winner there!

Just note that the only negative reviews were all about setup and wiring. One did however say the manufacturer was helpful.

[Erik Manchester]

Fred, that drive will do the job as well as the Teco FM50, however, the instructions for Asian VFD programming are notoriously poor and may leave one stretching their head if new to VFDs. All you would be doing is using it for phase conversion so the programming is simple, basically just entering motor parameters, and setting up the controls.

There are many YouTube examples of the FM50, perhaps less so with this one you are looking at. Teco provides a warranty and good support, but these newer asian VFDs are very reliable in my personal experience so hopefully not a factor. For that price you can buy two just to have a spare available. Once you figure out the configuration, write it down in case you have to replace it 18 months later, though that is unlikely.

[Dan Friedrichs]

I agree with Erik - that one looks identical to the "ebay special" I posted, earlier (but costs a bit more). It would be a bit of a challenge to program, and on a table saw, the speed adjustment likely wouldn't be very useful.

[Dave Cav]

I'm running two table saws, an 18" thickness planer, a tenoner, a mortiser and a drill press on individual VFDs. No problems and no derating of the motor. You can, however, sometimes derate the VFD. I'm running a 5 HP table saw on a 3 HP VFD. It all depends on the power requirements of the tool. On the other hand, my thickness planer, which also has a 5 HP motor, requires a 7.5 HP VFD to operate satisfactorily.

[Matt Day]

Dave, regarding the planer, I'm guessing it pulls a lot of amps so you had to step up the VFD size?

[David Kumm]

Jack Forsberg over at Canadian woodworking sells vfds and will program them to your motor. His prices are good. Dave

[Dave Cav]

Dave, regarding the planer, I'm guessing it pulls a lot of amps so you had to step up the VFD size?

Yes. The table saw with the 5HP motor is a Delta 12/14 and seldom if ever pulls anywhere near FLA, so I was able to successfully use a 3HP VFD with it. The planer is a helical head PM 180 and has a lot more going on under the hood, since both the cutterhead and the feed works are all powered off the same motor. Before I purchased the VFD I discussed it with the tech rep at Factorymation and he strongly suggested the 7.5 HP VFD, which has worked great for me. Still, despite the oversized VFD, I have managed to trip it on over current a couple of times when taking too heavy a cut with too fast a feed speed.

[Matt Mattingley]

Sizing a VFD for phase conversion boils down to current (amps). When going from a single phase input to three phase out put you will need the drive to be capable of putting out 1.73 times the motor nameplate amps. You roughly de-rate the drive by half. I work in the electrical field and we routinely put VFDs on three phase irrigation motors where only single phase power is available. They do not work unless properly de-rated. I suppose one exception would be a motor that isn't under a load and therefore not pulling anywhere close to its nameplate amps. Once a load is applied the drive would likely trip/fault if not sized correctly.
Yep you hit the nail on the head dead nuts,

The planer is a helical head PM 180 and has a lot more going on under the hood, since both the cutterhead and the feed works are all powered off the same motor. Before I purchased the VFD I discussed it with the tech rep at Factorymation and he strongly suggested the 7.5 HP VFD, which has worked great for me. Still, despite the oversized VFD, I have managed to trip it on over current a couple of times when taking too heavy a cut with too fast a feed speed.
In your situation buying a 7.5 hp three-phase VFD and only giving it a single phase power, it is D rated. 7.5÷1.73 equals 4.33 hp. You'll never overload your motor using that VFD, but you'll never truly reach the motor/machines potential. Technically the sales guy should've told you (maybe he did) this and you probably should've bought the 10 hp three-phase VFD and given it single phase power which would've given you a possibility of 5.78 hp. Been through the VFD you could have set maximum amperage out/ horsepower to be 8.65 hp. This would keep your output geared to your motor.

I also suggest you to touch base with Jack Forsberg.

Based on your title, VFD versus static converter, A static converter will only provide you three phase for start up then it only runs on single phase. This is a lot like having a three cylinder car engine only giving you power from two cylinders. This is called the D rating. A static converter is always the D rated! So if you buy a static converter, it will always be 3hp ÷1.73 equals 1.73hp. So Using a static phase converter on a 3 hp motor will end up being a 1.73 hp motor. No if and or butts! A static converter can only provide a motor 58% of its potential. A three phase VFD Fed single phase has the same problem! Except, if you overload a three phase D rated VFD it will trip like a breaker. If you overload a static phase converter, you could burn out the motor. A properly married VFD can have a potentiometer for speed control, breaking that will blow your mind, sensor less vector control, you can run numerous motors... using the same VFD powering the same machine. If you have a two Motor planer, You can size the VFD to start both. If you had five motor line shaper you can run all the motors with one VFD. There Single phase to 3 phase VFD's on the market that are not D rated. I have four of them running my shop. I'm waiting for the break resistor to go on the 18 inch table saw blade. Just imagine an 18 inch table saw blade coming to a stop in two seconds from 3600 RPM.

[Dan Friedrichs]

In your situation buying a 7.5 hp three-phase VFD and only giving it a single phase power, it is D rated. 7.5÷1.73 equals 4.33 hp. You'll never overload your motor using that VFD, but you'll never truly reach the motor/machines potential. Technically the sales guy should've told you (maybe he did) this and you probably should've bought the 10 hp three-phase VFD and given it single phase power which would've given you a possibility of 5.78 hp. Been through the VFD you could have set maximum amperage out/ horsepower to be 8.65 hp. This would keep your output geared to your motor.


Uhh...what?

I assume he has a 3-phase motor on the table saw, not a single phase motor....

Your whole post made no sense at all...

[David Kumm]

Matt's post makes perfect sense assuming that almost all vfd's rated larger than 5 hp are 3 phase input so they need to be twice the motor size to function under single phase input . A 3 phase input 7.5 hp rated vfd is slightly undersized for a 5 hp motor at full load. Doesn't matter most of the time but the larger vfd will be needed for planers, sanders, shapers and dust collectors. Not so much for saws. Dave

[Matt Mattingley]

Uhh...what?

I assume he has a 3-phase motor on the table saw, not a single phase motor....

Your whole post made no sense at all...

I assume you did read what I wrote below that quote??? And understand. Yes,no???

I was quoting two different situations and trying to help out in in-depth context. I made a couple edits to my post and I will clarify if clarification is required. Some people don't understand three-phase motors. Some people don't understand VFD's, RPC's, SPC to jump from single phase to three phase. I understand this thread to a Tee. Some might not want my knowledge. Some may only want to stay with single phase the rest of their life. I don't care which way you want to go, I personally just like to get machines working. Enjoy and have fun and make a living. Maybe I'm speaking in a language that most don't understand. I'm OK with educating, if you are willing listen. I'm even OK with you (or anyone) disputing anything I say! I'll even put up a shop videos!

[fRED mCnEILL]

Just to be clear now I am inputting 240 volts and the motor plate states:

3Hp,3Ph, 3450 RPM, KVA code letter H,Design letter B, Service factor 1.15,Hz 60, Volts 200, type 620M

Fred

[Matt Mattingley]

Just to be clear now I am inputting 240 volts and the motor plate states:

3Hp,3Ph, 3450 RPM, KVA code letter H,Design letter B, Service factor 1.15,Hz 60, Volts 200, type 620M

Fred is not good to utilize your service Factor in the programming of the VFD. Technically you want a 2.2 kW VFD. Most VFD's are rated in kilowatts (KW). Most European motors are rated in kilowatts. Most north American motors are rated in horsepower. If the conversion confuses you a little bit... here are the numbers.


Rules of conversion => 1 hp = 0.7457KW or 1 kW =1.341 hp
VFD

Single phase VFD input to three phase output. => 1 hp = 0.7457KW or 1 kW =1.341 hp.

Three phase VFD with single phase in feed, output is => hp ÷1.73="X". Then... "X" x 1.73 x 1.341= Three phase VFD in KW required. Then round up. This is the VFD you need. Or Just go, =>
hp x 1.73 to rate Single phase input to three phase out put.
example is a;
3hp 3p motor with a VFD rated for three-phase input you would need a three phase 5.2 hp VFD.
5hp 3p motor with a VFD rated for three phase input you would need hey three-phase 8.65 hp VFD.

To make things more confusing, there are single phase 3hp VFD's with a rated three phase output. The Vfd is required to have single phase amps of 15 A (in output is only 2.2 kW or) and has an output of three phase 10 A. Kind of funny how that works? Sounds like the conservation of energy law hitting me in the head again.


I think it's that easy.?

[mreza Salav]

Fred, in case these are causing confusion: typically these derating calculations are used when you use a VFD that is designed with 3PH input but is fed with single phase input (like a static converter, or when you run a 3ph motor with single phase power). The FM50 linked above and also those models on e-Bay (rated at 3HP) are good to use for a 3HP 3PH motor when you convert single phase. I have both models and use on different machines.

[Dan Friedrichs]

Ah, I see, now. Yes, Matt is talking about using a 3-phase input VFD with only a single phase input connected, so there's a sqrt(3) factor to scale the input power by. Just to be clear, the OP does not need (or want) to do that :)

It's a good point, though, that for larger loads (>5HP), VFDs are generally built with 3-phase input. There is no technical reason that they can't be single-phase (just like there is no technical reason you couldn't build a 1,000HP motor that runs on single-phase) - but beyond some power level, the advantages of using 3-phase (namely: twice the power for a given conductor size) begin to outweigh the cost of installing the service. But, it is possible to get >5HP VFDs with single-phase input (or, you can do as Matt is saying, and derate a VFD that has a 3-phase input).

HOWEVER - that has nothing at all to do with the OPs question.

Fred, does your motor list FLA (full load amperage) on it? That would be the important parameter to see that the VFD is sized correctly.

[David Kumm]

So the motor is actually an old 200v motor? The vfd can be adjusted to output 200v but keep in mind it must be sized to output the needed amperage @200v, not 240. VFD amperage output will be less at 200v so the vfd needs to be sized a little bigger to give a little cushion.

EX. Motor FLA @ 200v is 10 amps. Vfd needs to output 12amps at 240v. Dave

[Dan Friedrichs]

David, you're right - that's why I asked what the motor FLA was. The VFD needs to be rated for greater output current because it will need to be programmed to limit output voltage to 200V. It doesn't make sense to spec a VFD based on horsepower - it should be specd on rated voltage and current.

However, the TECO VFD that I linked, way earlier in the thread, is rated for 150% current for 1 minute. For something like a table saw, that seems ideal.

[fRED mCnEILL]

Dan,
No FLA.

In addition to this
3Hp,3Ph, 3450 RPM, KVA code letter H,Design letter B, Service factor 1.15,Hz 60, Volts 200, type 620M

it also has the following.
time rating-CONT,Amps. 7.8,

Also in a blank space is F179 and it is a Rockwell 87-353 so its an old motor.

If its any help the person I bought it from used a Phase-a-Matic static phase converter (model PAM HD900)that had- HP range min.4 and max 8. Also Single phase full load amps 22.

Thanks

Fred

[David Kumm]

Fred, just to be clear. you need a vfd to adjust the voltage to 200. 200v motors were used back in the day and while OK with a 208v three phase service, may not like the 240v now used. Depends on the motor but the owwm guys will generally buck the voltage down or use a vfd to get service voltage closer to 200. It sounds like the real question should have been how to adjust the voltage which a static or rpc won't do at all. Dave

[Dan Friedrichs]

So the full-load continuous amp rating is 7.8A. Good. So the TECO is rated for 10.5A (more than enough), and the "LAPOND" on you linked on Amazon is rated 10A. Either of those will work.

As David says, though, you likely need to step the voltage down to 200V, max. Honestly, the motor may run just fine at 240V, but to be safe, you'd want to reduce the maximum voltage applied (you risk zapping the winding insulation and/or magnetically saturating the motor if you run the voltage TOO high).

Looking through the manual for the TECO, I don't immediately see how to set that limit. I'm pretty sure the Amazon one will let you program the max voltage limit, though.

[Matt Mattingley]

If TECO does not specifically state in there PDF/manual, that output voltage is adjustable from 208-260, I would be leery using that model as providing it with your actual hot (measured from hot the hot leg) The motor could be getting 235 V to 255 V depending on your service. You could fry the motor. Dan says he is pretty sure his Amazon one has output voltage adjustment. So there you go.

In my opinion if it is a 200 V rated motor, there is a 10% rule. Do not give a motor +-10%. So anything more than 220 V can be harmful and burn out the motor. Whenever VFD you purchase, make sure the output voltage is adjustable to achieve less than 220 V output if you plan on keeping the motor.

[Dave Cav]

In your situation buying a 7.5 hp three-phase VFD and only giving it a single phase power, it is D rated. 7.5÷1.73 equals 4.33 hp. You'll never overload your motor using that VFD, but you'll never truly reach the motor/machines potential. Technically the sales guy should've told you (maybe he did) this and you probably should've bought the 10 hp three-phase VFD and given it single phase power which would've given you a possibility of 5.78 hp. Been through the VFD you could have set maximum amperage out/ horsepower to be 8.65 hp. This would keep your output geared to your motor.


That's true, I am losing a bit of capacity with my nominal 7.5 HP VFD. However, there is a significant price difference between a 7.5 and a 10HP VFD, and it was even greater when I did the initial setup. Given the overcurrent capacity of the VFD, it works pretty well for what I'm doing, but yes, a 10 HP would be ideal.

[jack forsberg]

Fred, just to be clear. you need a vfd to adjust the voltage to 200. 200v motors were used back in the day and while OK with a 208v three phase service, may not like the 240v now used. Depends on the motor but the owwm guys will generally buck the voltage down or use a vfd to get service voltage closer to 200. It sounds like the real question should have been how to adjust the voltage which a static or rpc won't do at all. Dave. Really the important thing here is not the voltage but that the base frequency can be set . If the base frequency can be set then motor speed can be adjusted . In the case of this motor the volt frequency ratio is 1 to 3.333 hzs . To be quite honest I can't believe they're still selling the FM 50 which is of course not capable of setting base frequency. Last time I talk to Teco they suggested raising the Hzs output to 72 Hz for a 208 volt Motor we were running. You would have to sit Fred's Motor to 80 hzs out put frequency for that motor to like the voltage . Of course this eliminates all speed control because that's the only position the voltage hzs ratio exists for a 200 V motor in the FM 50 . Being feed house hold. My drives have voltage and base frequency input as well run static tests to sync the motor to the drive . These are VF sensorless and sensor vector option too for approximately the same price As the antiquated FM 50 . Lastly suggestions of running the motor on existing voltages will surely fry the motor overtime especially considering that a proper drives the same price . Because it's a high-speed motor it's probably not advisable to run it at 80 Hz

[Tim McCarthy]

I am in process of purchasing one or (hopefully) two machines of three phase ilk. One a 20" planer, the other a 12" jointer. Both are 5 Hp and start under minimal load. Phase-a-matic has static phase converters that will be about $200 ea and are supposed to yield right about 2/3 the rated HP. I have a similar static converter (same company) on my 5 hp 3 ph pin router. It's an old Ekstrom Karlson 232 and I certainly never miss the extra power! Why would/should I spend the extra money on a VFD?

thanks in advance for any advice

Tim

[jack forsberg]

I am in process of purchasing one or (hopefully) two machines of three phase ilk. One a 20" planer, the other a 12" jointer. Both are 5 Hp and start under minimal load. Phase-a-matic has static phase converters that will be about $200 ea and are supposed to yield right about 2/3 the rated HP. I have a similar static converter (same company) on my 5 hp 3 ph pin router. It's an old Ekstrom Karlson 232 and I certainly never miss the extra power! Why would/should I spend the extra money on a VFD?

thanks in advance for any advice

Tim Tim if you're interested in any of my VFD's they're all single phase in put their not D rated and I sell a range from 2 hp to 15 hp . All are single phase in put with parameters for single phase . My 5 hp drive is $275 and that is the total price . Shipping is an additional $58 anywhere in North America . The 15 horse power is $1000 of that is about one third the cost of phase perfect . Larger drives run more than one Motor at the same time when set to VF control . You can contact me at jack@jforsberg.ca if you'd like further information or you can view the playlist on my YouTube station" Jack English machines" on VFD's from the Wadkin temple .

[Bradley Gray]

5hp is really minimal for a 20" planer. I would get a converter that can bring on all 5 horses.

I have a 24"7hp planer and recently upgraded from a 7hp RPC to 10hp RPC. The planer works 100% better.

[Erik Manchester]

A planer is a hard start as the head requires a fair bit of power to get the iron moving, my 25" planer has a 10 hp motor and my 15 hp RPC starts it, but if I had the planer before the RPC I would have purchased a 20 hp. Thankfully my RPC was designed to handle hard starts and can deliver the current needed to get the 6" diameter head turning. Better to have a little extra capacity than too little capacity.