Help Me Select a VFD Please

[AccelR8]

I've got used milling machine I'm going to set up at home. I have 220V single phase power. The machine has a 220/440V 3 phase motor. It is currently wired for 440 but it can be rewired for 220.

It is rated at 2 HP and 6.0 amps at 230V.

I am looking at two possible VFD candidates, both are KB Electronics. One is KBAC-29, 3.0 HP 9.0 amps output. The other is 2.0 HP, 6.7 amps output.

It's my understanding that it is best to have a VFD that is over rated relative to the motor. Is this correct? If so then I would choose the 3.0 HP one.

Advice/experience appreciated. I did this with a lathe several years ago but not knowing what I was doing I went to an electric motor service shop and let them select a drive for me. Looking at prices today I see I paid them about three times what I could have bought the drive for on line. Not that I don't feel their expertise was worth it, but I want to save that premium this time around.

 

[akajun]

No need to over rate on a vfd
Change your machine to 220v
Find a teco/ Westinghouse or Hitachi 2hp vfd
220v single phase in 220v 3 phase out
Should be less than $200

 

[GNERGY]

Westinghouse Teco FM50 I have 2 of them with no problems. Changed the motors to 220V.
Tarey

 

[ridgeway]

I got a Teco L510 to drive my 2hp mill. It replaces the discontinued teco fm50. I have the FM50 running my lathe. The L510 has way more programming features that boggles my mind. Both do an excellent job. If you have a 2HP motor, get a 2hp vfd. Simple. Any questions feel free to pm me... I'm no electrician or expert, but figured out the ins and outs to get stuff wired to the switches and pot dials.

 

[rwj]

Admittedly not well experienced with VFDs... but isn’t whether the motor is VFD compatible also a concern?

 

[ridgeway]

Admittedly not well experienced with VFDs... but isn’t whether the motor is VFD compatible also a concern?

My mill runs fine so far. I've read conflicting reports on that. I will cross that bridge if smoke pours out, lol. I think it will be fine...

 

[AccelR8]

Admittedly not well experienced with VFDs... but isn’t whether the motor is VFD compatible also a concern?

When I did my lathe I initially thought that but apparently as long as it's a 3 phase motor it'll work. I think maybe yeah it's one of those things where theoretically the two should be matched but in the real world...

 

[AccelR8]

Kinda likin' that L510-202-H1-U

 

[rwj]

My mill runs fine so far. I've read conflicting reports on that. I will cross that bridge if smoke pours out, lol. I think it will be fine...

My understanding is that excessive heat will be generated in non-VFD motors when operated at frequencies other than 60 hertz. Probably not an issue if the duty cycles are short!

 

[AccelR8]

I got a Teco L510 to drive my 2hp mill. It replaces the discontinued teco fm50. I have the FM50 running my lathe. The L510 has way more programming features that boggles my mind. Both do an excellent job. If you have a 2HP motor, get a 2hp vfd. Simple. Any questions feel free to pm me... I'm no electrician or expert, but figured out the ins and outs to get stuff wired to the switches and pot dials.

Are you using it as your primary speed controller or are you still using the mill's variable speed, and leving the vfd at a fixed setting?

 

[ridgeway]

I mainly use my variable speed on the head. Main reason is so that the pulley and all the moving parts don't settle in one spot and the motor is continously on 60hz. My head needs some attention as my pulley sticks at times when I crank my dial. A lot of the programming features are left alone. I have the VFD side connected to the factory drum switch and have a pot dial set up incase I need to adjust the speed in a pinch. About the only time would be to slow it down even more on the bottom side of low or even high.

 

[butchlambert]

I have both the Hitachi and Westinghouse-Teco. I would recommend adding braking resistors at almost no cost. With those I can program my spindles for instant stop if I need it. I have 2 1960s Bridgeports that I installed the VFDs on and I think they were built pre VFD.

 

[ridgeway]

I have to look into that Butch. I tried programming the mill vfd to stop fast, but VFD don't like it.

 

[rwj]

I have both the Hitachi and Westinghouse-Teco. I would recommend adding braking resistors at almost no cost. With those I can program my spindles for instant stop if I need it. I have 2 1960s Bridgeports that I installed the VFDs on and I think they were built pre VFD.

Yup... without resistors there’s no way to dissipate the current created by the motor during deceleration when it becomes a generator.

 

[hoz53]

Admittedly not well experienced with VFDs... but isn’t whether the motor is VFD compatible also a concern?

its best to have an inverter rated motor. they are designed to operate at different frequencies. most people will hook up a vfd to an existing motor and use till it until they smoke it, to get what they can out of it then get a new inverter rated motor.

 

[tobnpr]

Ditto on the Teco L510.
Parameter programming instructions that you can actually read and understand...

 

[tobnpr]

ts best to have an inverter rated motor. they are designed to operate at different frequencies. most people will hook up a vfd to an existing motor and use till it until they smoke it, to get what they can out of it then get a new inverter rated motor.

This.
Mine's also explosion-proof, just 'cause I got a smoking deal on a NOS one locally.

I don't think you'd likely have an issue if you're always running at 60 hz. But if you're going to overspeed/underspeed, you need that rating to protect the windings from what I understand.

 

[hoz53]

This.
Mine's also explosion-proof, just 'cause I got a smoking deal on a NOS one locally.

I don't think you'd likely have an issue if you're always running at 60 hz. But if you're going to overspeed/underspeed, you need that rating to protect the windings from what I understand.

yes thats true about always running at 60hz since thats what the motors designed for. the vfd generally varies the speed by varing frequency. that can cause overheating in windings not designed for that. Now all i gotta do is figure out how to program this hitachi vfd to make it work.

 

[hoz53]

Ditto on the Teco L510.
Parameter programming instructions that you can actually read and understand...

thats what i need - i cant figure out this hitachi, thats for sure.

 

[B Nettesheim]

If you guys want to save some headaches starting up or programming your drives get an ABB or Danfoss they have a great support service. Ive used them for a long time with no trouble. Look locally for a used one if you wish as they can be had for about $100-$200. I can walk you through start up too.