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View Full Version : Size and sourse for VFD



JoeFin
09-12-2010, 12:35 PM
I know I'm going to get a lot of replies recommending Teco VFDs but at least explain why. Personally I prefer and work with Allen Bradly 400 / 300 series Power Flex drives, but never fed from a single phase sourse

I'm looking for a "Good Deal" on a VFD for my 5-Hp Leblond motor that I'll be powering with 240v single phase. I'll need to derate the VFD properly as to allow the 240v line side supply. I was thinking a 7.5-Hp or 10-Hp VFD would be adequate.

Additionally which features do you find the most beneficial in the operation of your LATHE, - accel time, breaking, ect, ect

quadrod
09-12-2010, 12:38 PM
Try automationdirect.com. Have three and work fine.

quadrod
09-12-2010, 12:41 PM
How rude of me, here is the link.
http://www.automationdirect.com/adc/Home/Home

JoeFin
09-12-2010, 01:04 PM
How rude of me, here is the link.
http://www.automationdirect.com/adc/Home/Home

Great website but they don't have any thing for a 5-Hp motor with a single phase input

wierdscience
09-12-2010, 01:25 PM
Breaking is a nice feature,stopping the chuck in one rev from 1,000 rpm is nice.

As for the AB drives,I like them too,but never tried 1~ input to one.It might be possible I have some AB's that I rescued from the scrapyard,440vac inputs,but in programing I noticed a que for voltage and explored it,it listed 220 and 440 as options,so I selected 220 and it worked.It derated it by 1/2,but since I got the things for free who cares right?

Here are some VFD's being sold as 1~ input units,but I have to wonder if they are really derated 3~ being sold for more money.

http://www.driveswarehouse.com/Drives/AC+Drives/Phase+Converter+VFD/PC1-50.html?osCsid=18daa3ae1dcb6afd5937a02c3a4cb4b0

Pherdie
09-12-2010, 01:34 PM
You may find that a VFD may not be your best resort, Joe.

When you get into the 5HP range, a single phase powered VFD usually doesn't offer 'constant torque' (sensorless vector), is extremely pricey and sucks some sizeable power, taxing older residential power installations.

Your best bet might be a rotary phase converter (and that's coming from a big VFD fan).

Good luck,

Fred

wierdscience
09-12-2010, 01:40 PM
I wish some one here would buy a Phase Perfect and then post a schematic for a DIY version.Sadly they cost a mint:(

http://www.phaseperfect.com/

JoeFin
09-12-2010, 01:42 PM
Your best bet might be a rotary phase converter (and that's coming from a big VFD fan).

Good luck,

Fred

My RPC is rated for 7.5 Hp but no single motor over 3 Hp

Question being is it better to build a larger RPC or look for a VFD that will handle the job

Bmyers
09-12-2010, 01:44 PM
how often is that LeBlonde actually going to be pulling 5hp ?

JoeFin
09-12-2010, 01:50 PM
What do you guys think of this 1

http://cgi.ebay.com/4KW-VARIABLE-FREQUENCY-DRIVE-INVERTER-VFD-NEW-5HP-New-/260651485980?pt=LH_DefaultDomain_0&hash=item3cb00a0b1c

lakeside53
09-12-2010, 01:51 PM
Your could make/buy a larger rpc, or add a secondary (say 7hp) idler (that's different to what the manf is refering to "max starting hp load" to your existing rpc (increase fuse and/or breaker sizes...). Then if you like, run that into the much cheaper surplus 3 phase only vfd's...

Specs... my commercial rpc is supposed to start a 5hp load, but it won't start my 4hp lathe in higher gears. Well... it will, but the voltage sag on the generated leg is so much that the thermal trips on the lathe pop (just as well).


There are several 5hp single phase input vfd's available. Ignoring the Chinese non-major-brand "shipped direct from Hong Kong" models, most are about $600.

lakeside53
09-12-2010, 01:53 PM
What do you guys think of this 1

http://cgi.ebay.com/4KW-VARIABLE-FREQUENCY-DRIVE-INVERTER-VFD-NEW-5HP-New-/260651485980?pt=LH_DefaultDomain_0&hash=item3cb00a0b1c



I looked at those when I was trying to decide what to do.

It's your money... personally, I won't buy that stuff. Yes, it's half the cost of the USA made stuff, but I won't risk my motors etc. Ask them if it's UL approved. When they say yes, ask them for the testing and approval numbers...

dp
09-12-2010, 02:02 PM
I have a 1θ to 3θ AB VFD that just kicks butt. It's only 1HP, but all I need is 1HP. Very feature rich including the much appreciated braking by winding the frequency down to 0 Hz while powering the motor. No big resistors needed.

wierdscience
09-12-2010, 02:04 PM
What do you guys think of this 1

http://cgi.ebay.com/4KW-VARIABLE-FREQUENCY-DRIVE-INVERTER-VFD-NEW-5HP-New-/260651485980?pt=LH_DefaultDomain_0&hash=item3cb00a0b1c

That's a router spindle drive,notice the 400htz upper.

Could you see an 1800 rpm motor running at 400htz:eek: :eek:

There is another seller in Hong Kong goes by Happy,lucky sunshine or some such that sells 0-120htz models,I think EVguru has bought from them.

Pherdie
09-12-2010, 02:10 PM
What do you guys think of this 1

http://cgi.ebay.com/4KW-VARIABLE-FRE...em3cb00a 0b1c


In my opinion there is insufficient information in the posting to use that unit. There is no mention of derating when utilizing single phase power and no mention of actual maximum input power required for quoted output, a real "pig in a poke."

5 HP requires a lot of electrical power (from a residential standpoint), especially to get a motor started, and the old US motors really made their rated power, necessitating adequate input power.

lakeside53
09-12-2010, 02:19 PM
Pheride -a 5hp driven from a vfd will not require a large amount of "startup" power in the conventonial motor starter sense - the vfd is effectively a 'soft start" as current limits while frequenty is ramped.


Joe : if you use a vfd make sure your lathe does not have a mechanical oil pump. If it does, check the flow/pressure at lower and higher speeds than nominal. My lathe has such a pumpo, and until I get a chance to dig deeper into the oil issue, it's staying on an rpc.

derekm
09-12-2010, 03:15 PM
...

As for the AB drives,I like them too,but never tried 1~ input to one.It might be possible I have some AB's that I rescued from the scrapyard,440vac inputs,but in programing I noticed a que for voltage and explored it,it listed 220 and 440 as options,so I selected 220 and it worked.It derated it by 1/2,but since I got the things for free who cares right?

Here are some VFD's being sold as 1~ input units,but I have to wonder if they are really derated 3~ being sold for more money.

...
ABB make 3~ to 3~ and 1~ to 3 ~ They are different units. I have 2 of the now absolete ACS1xx series, bought off ebay for a song. They work fine, running my shaper, 3 motors on the mill (vert, horiz, feed) , and the athe. Running from about 10 hz to 75hz. I use a bank of 3 ~ contactors to switch between the motors.

Black_Moons
09-12-2010, 04:13 PM
I have a 1θ to 3θ AB VFD that just kicks butt. It's only 1HP, but all I need is 1HP. Very feature rich including the much appreciated braking by winding the frequency down to 0 Hz while powering the motor. No big resistors needed.

Actualy, thats not braking very much at all. Its a matter of energy conservation that when you slow a motor, the energy MUST go somewhere.

In the case of ramping down the freqency, the energy goes BACK into the vfd. Some losses will spit some of that energy out as heat, but generaly it goes into bumping the VFD's DC bus voltage up. It may have small internal resistors to handle a small overload, but if you set your deaccel time too short with too large a mass being driven, you'd get 'Overvoltage trip' and the VFD will let the motor freewheel. (Higher 'gears' will produce more effective mass to slow down, so whats fine at a low gear can trip at a higher gear)

Not something you want to learn while turning a large workpeice at high RPM's while threading up to a shoulder, relieing on the VFD to stop it!

PS: the alternative, DC injection, causes the energy to be disipated as heat inside the motor. OK for the odd stop now and then, but not good if your stoping the lathe every 10 seconds to reverse and make another threading pass

JoeFin
09-12-2010, 04:14 PM
I looked at those when I was trying to decide what to do.

It's your money... personally, I won't buy that stuff.

Yep - thanks for the information. Those were my thoughts exactly

JoeFin
09-12-2010, 04:28 PM
Joe : if you use a vfd make sure your lathe does not have a mechanical oil pump. If it does, check the flow/pressure at lower and higher speeds than nominal. My lathe has such a pumpo, and until I get a chance to dig deeper into the oil issue, it's staying on an rpc.

The 13" LeBlond is a "Slinger"

The main concern is to power the lathe

I'm concerned about inrush currents on my tiny 200 amp residential service. Enough good inrushes and I wouldn't give a plug nickle for any of it working much less the 1 branch circuit this thing is riding on. Machine tools belong on "Bolt On" Ckt breakers for a reason

Secondly - I'm checking cost effectiveness over building up a larger RPC. I'm pretty happy with the 7 1/2 Hp Ronk Rotophase I have. I realize I could just use a 3 into 3 phase VFD and ramp the power as to not exceed the start currents the Ronk is listed for.

Or I could use a VFD on the Lathe and have the CNC or Automatic Surface grinder running on the RPC at the same time too. Not some thing I do very often but when the creative juices are running I like to go with it

dp
09-12-2010, 04:41 PM
Actualy, thats not braking very much at all. Its a matter of energy conservation that when you slow a motor, the energy MUST go somewhere.

My understanding of it is that braking active braking is no different than accelerating the motor. It is sending power to the motor to overcome inertia speeding up or slowing down. The motor is used to overcome it's own stored energy. This might be a good thread on it's own so we don't highjack this one :)

j king
09-12-2010, 04:56 PM
I run a 10 hp lathe off 220 single phase from an ac drive. It works for 75% of the time. If I have a heavy turning task I fire up the 15 hp rpc I built and get full hp from the drive. This is same on my 10 ee. It has a 5 hp drive and a 5 hp motor. If I fault out because off too much weight running too fast I fire up rpc. Both machines are wired with all 3 legs from breaker panel. When I fire up rpc it feeds the 3 line and away I go. No problems.. Jim

macona
09-12-2010, 06:32 PM
My understanding of it is that braking active braking is no different than accelerating the motor. It is sending power to the motor to overcome inertia speeding up or slowing down. The motor is used to overcome it's own stored energy. This might be a good thread on it's own so we don't highjack this one :)


No, in braking the motor becomes and alternator and the power is dumped through a big power resistor. The one on my friends mill is about 2-1/2" diameter and 18" long. Haas uses range elements in their mills for braking resistors.

Yaskawa and mitsubishi make some nice larger VFDs that will work great for what you want to do. I dont like RPC's. Its not true three phase out and you can feel it. Plus they waste a lot of power just sitting there running and are noisy.

macona
09-12-2010, 06:36 PM
I run a 10 hp lathe off 220 single phase from an ac drive. It works for 75% of the time. If I have a heavy turning task I fire up the 15 hp rpc I built and get full hp from the drive. This is same on my 10 ee. It has a 5 hp drive and a 5 hp motor. If I fault out because off too much weight running too fast I fire up rpc. Both machines are wired with all 3 legs from breaker panel. When I fire up rpc it feeds the 3 line and away I go. No problems.. Jim

I assume your 10EE has a module drive if it has the 5HP motor. If that is the case it makes no difference wether you run it off of single or three phase because the module and the older wiad drives both run on single phase. 3 phase is only needed for the coolant pump if equipped, otherwise the 10EE is a single phase machine unless you have an older MG or newer (after '83) regen drive.

Or did you do a retrofit? I cant remember.

Black_Moons
09-12-2010, 06:41 PM
My understanding of it is that braking active braking is no different than accelerating the motor. It is sending power to the motor to overcome inertia speeding up or slowing down. The motor is used to overcome it's own stored energy. This might be a good thread on it's own so we don't highjack this one :)

Sorry, but that would clearly violate the first law of thermodynamics
http://en.wikipedia.org/wiki/First_law_of_thermodynamics

You can't use energy to destory energy. Infact you can not destory energy period. Energy has to go somewhere. It can only be transformed into diffrent types of energy. the most typical end product being heat.

Object rotating has more energy then a stationary object. You can not use energy to stop it, you must extract energy.

JoeFin
09-12-2010, 06:52 PM
Does anyone have a good recommendation for a SOURCE of a suitable drive.

Lots of good advice and information here - don't get me wrong.

But as of yet none of the links posted or any of the drives I've located on Eboner been a suitable application for my lathe. A couple of the EBoner adds eluded to 1 phase operation, but when I pulled up the manual and read the details, the seller was salivating on himself rather then listing a suitable "Single Phase in / 5 Hp drive" for my lathe. And at the prices they were listing I might as well order from a reputable supplier in my area

Erik Brewster
09-12-2010, 07:48 PM
I've used Hitachi drives from www.driveswarehouse.com. They have one drive (not Hitachi) that is rated for 220V single phase, 5 Hp. I've had good luck with them for two VFDs. I've never had to deal with any problems through them, so their support is an unknown to me. I seem to recall that they shipped pretty quickly.

http://www.driveswarehouse.com/Drives/AC+Drives/Phase+Converter+VFD/PC1-50.html

macona
09-12-2010, 07:57 PM
Does anyone have a good recommendation for a SOURCE of a suitable drive.

Lots of good advice and information here - don't get me wrong.

But as of yet none of the links posted or any of the drives I've located on Eboner been a suitable application for my lathe. A couple of the EBoner adds eluded to 1 phase operation, but when I pulled up the manual and read the details, the seller was salivating on himself rather then listing a suitable "Single Phase in / 5 Hp drive" for my lathe. And at the prices they were listing I might as well order from a reputable supplier in my area


Ebay. Virtually any drive that will take three phase in will run off of single phase. My friend uses a 15HP Yaskawa to run the 10HP spindle in his VMC and it is ran off single phase. Find a drive that looks promising, 7.5HP+, 200-240v and look through its manual for any reference to phase loss or dropped phase detection. A few drives out there will detect when it is single phasing and send out an error signal. Often this can be remedied by jumping one hot to the extra line terminal. Yaskawa and Mitsubishi has excellent support for manuals for even their older drives.

wierdscience
09-12-2010, 08:44 PM
Does anyone have a good recommendation for a SOURCE of a suitable drive.



What do you mean by suitable?The first one I linked to is 1~ 220vac input and 3~220vac output rated at 5hp,they also have 7-1/2,10 and 15hp.The bottom of the page says MFG POLYSPEDE -Made in USA.$599 and free shipping.$200 more gets you a 7-1/2hp.

If your looking for a 1~ input VFD that size I don't think one will show up on Ebay.If it did the price will most likely be the same.

j king
09-12-2010, 10:01 PM
I assume your 10EE has a module drive if it has the 5HP motor. If that is the case it makes no difference wether you run it off of single or three phase because the module and the older wiad drives both run on single phase. 3 phase is only needed for the coolant pump if equipped, otherwise the 10EE is a single phase machine unless you have an older MG or newer (after '83) regen drive.

Or did you do a retrofit? I cant remember.
Macona. It was a retro..

whitis
09-12-2010, 11:24 PM
Your could make/buy a larger rpc, or add a secondary (say 7hp) idler (that's different to what the manf is refering to "max starting hp load" to your existing rpc (increase fuse and/or breaker sizes...). Then if you like, run that into the much cheaper surplus 3 phase only vfd's...


Then you have the inefficiency of an RPC combined with the inefficiency of a VFD.

A 3-phase VFD is likely to run off single phase if you make the following adjustments:
- The diodes on the input may be overloaded because power is coming in on fewer input legs, so you may need an external bridge rectifier feeding into the DC bus of the VFD.
- The capacitor bank needs to be much bigger because there is much more ripple from single phase
- Input wires/terminal strips have to be checked to be able to handle the increased current on the legs that are used.

There are subtle reasons why some might still not work.

JoeFin
09-13-2010, 12:02 AM
What do you mean by suitable?The first one I linked to is 1~ 220vac input and 3~220vac output rated at 5hp,they also have 7-1/2,10 and 15hp.The bottom of the page says MFG POLYSPEDE -Made in USA.$599 and free shipping.$200 more gets you a 7-1/2hp.

If your looking for a 1~ input VFD that size I don't think one will show up on Ebay.If it did the price will most likely be the same.

I didn't see where it was constant torque and the 600 Hz output looked a bit high. Probably do well in other applications.

I also looked at Google Earth to see Polyspeed's operation

wierdscience
09-13-2010, 01:21 AM
According to the manual it can be programed for ether constant torque or variable torque.

Dunno about the Freq,might be worth a call,if nothing else to find out if they really are made here.

dp
09-13-2010, 03:03 AM
Sorry, but that would clearly violate the first law of thermodynamics
http://en.wikipedia.org/wiki/First_law_of_thermodynamics

You can't use energy to destory energy. Infact you can not destory energy period. Energy has to go somewhere. It can only be transformed into diffrent types of energy. the most typical end product being heat.

Object rotating has more energy then a stationary object. You can not use energy to stop it, you must extract energy.

I'm talking about DC. If you match the back EMF in frequency but lead it in phase you inject DC and that is active braking, not passive braking.

EVguru
09-13-2010, 07:36 AM
That's a router spindle drive,notice the 400htz upper.

Could you see an 1800 rpm motor running at 400htz:eek: :eek:

There is another seller in Hong Kong goes by Happy,lucky sunshine or some such that sells 0-120htz models,I think EVguru has bought from them.

My elderly Simovert goes to 400Hz too.

Many of these units are being sold with high speed spindles and often come setup for 400Hz operation.

I do indeed have one of these drives and so far I'm happy with it. It's a 3hp model and is installed on my Harrison L5. They appear to have been built with an over-specified rectifier, so there's no downrating when used on single phase. My 3hp doesn't have the components fitted to do dynamic braking, but does have DC injection braking although I'm not using it. It can stop my 5" three jaw from 2000rpm (133Hz) in top gear in 2 seconds without tripping an overcurrent. When I rebuilt the lathe, I left out the clutch/brake operating mechanism and haven't missed it.

I have a 4hp version sitting in its box that I bought for the Avon CNC and that is meant to have the dynamic braking, but I've yet to confirm it.

lakeside53
09-13-2010, 12:19 PM
Joe : Don't sweat the upper LIMIT - it's programmable. Even a low end unit will go to 200%, but you not likely use it at those limits. My Hitachi units all go up to 400%, but I typically set the upper limit for my machine use to 150% (90hz).

lakeside53
09-13-2010, 12:27 PM
Then you have the inefficiency of an RPC combined with the inefficiency of a VFD.

.


Sure.. just a way to use dirt cheap surplus 3 phase vfd. If he's buying a VFD, only the "extra" from the rpc needs to be considered. A 7.5hp (true, not "max possible connected load) likely draws about 300 watts at idle (high current, very low pf) , plus some losses as power is drawn.

Even though I have vfd's everywhere, I find it very useful to also have an rpc - sometimes I just need "3 phase", and need to power a system, not just a motor.

Black_Moons
09-13-2010, 03:10 PM
I'm talking about DC. If you match the back EMF in frequency but lead it in phase you inject DC and that is active braking, not passive braking.

DC injection braking is provided by just provideing DC to the coils, no alteration of freqency at all, it turns the motor into a electromagnetic break that converts the power of rotation into heat via eddy currents.

Way diffrent then dynamic braking provided by slowing the freqency provided to the motor, turning it into an alternator.

derekm
09-14-2010, 05:33 PM
Breaking is a nice feature,stopping the chuck in one rev from 1,000 rpm is nice.

As for the AB drives,I like them too,but never tried 1~ input to one.It might be possible I have some AB's that I rescued from the scrapyard,440vac inputs,but in programing I noticed a que for voltage and explored it,it listed 220 and 440 as options,so I selected 220 and it worked.It derated it by 1/2,but since I got the things for free who cares right?

Here are some VFD's being sold as 1~ input units,but I have to wonder if they are really derated 3~ being sold for more money.

http://www.driveswarehouse.com/Drives/AC+Drives/Phase+Converter+VFD/PC1-50.html?osCsid=18daa3ae1dcb6afd5937a02c3a4cb4b0

Which parameter number was that on the drive? I have a 3~ ACS 100 drive i would like to use on 240 1~