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Specific VFD questions

Sdhorton

Plastic
Joined
Apr 8, 2021
I have searched all I can find on power conversions and have decided that a VFD is the way to go.
I bought a South Bend heavy 14 that research shows has a 3 hp motor and a reeves variable speed system.

Can someone give me very specific recommendations on on what size, style, and name brand of VFD I should buy and what is needed to hook it up.

Thanks
Shane
 
If you want VERY SPECIFIC recommendations, call your local motor shop or VFD supplier and let them spec it out for you.

In general - they are sized based on motor HP, so you need a 3HP drive. Name brand is up to your budget. If your duty cycle is low, a cheap one may work great. If this is in full production use, you may want a name brand.

You also need to specify what input and output voltage you want.
 
My mistake, input power is 220v single phase, output needed is 220v three phase, motor is 3hp, I assume 60 cycle but don't have access to the spec plate on the motor right now.
Use would be fairly light duty, hobby or light industry, intermittent use.
I have no local suppliers, whatever I buy will be from out of town, there is no one local with the knowledge I need.
 
I've used a Teco L510-203-H1-U on a 3HP in an old Monarch. Single phase 220V in 3phase 220out. It's not the only solution, just one possibility. Looks like about $240 from various suppliers. Pick a supplier and give them a call with the motor dataplate info in hand.
 
That's the sort of reference I am looking for, Thank you. Is the set up as easy as it looks, just wires in and wires out?
 
That's the sort of reference I am looking for, Thank you. Is the set up as easy as it looks, just wires in and wires out?

I have a lot of experience with electronics, so it was trivial for me. A lot will depend on whether you're using the panel controls, or remote switches and pot. Any VFD will have parameters that have to be entered. Several YouTube videos on the Teco L510.
 
I would suggest a bit more research on the particular machine you are talking about. I am not aware of a SB Heavy 14 with a Reeves drives, so are we discussing a mill or a lathe? There is also a lot of other variables such as the drive system, is it a flat belt or V belt, what motor is on it currently and if a lathe is it a thread on chuck mount or a D1-4 type?

TWO TYPES SB 14 1/2 Lathe HEADSTOCKS
Six to Sixteen Spindle Speeds Headstocks for 141/2" swing South Bend Lathes are made in two types: 4-step cone pulley and wide belt 3-step cone pulley. The 4-step cone pulley headstock provides either eight or sixteen spindle speeds depending on whether a single speed or a two-speed motor is used. With the wide belt 3-step cone pulley you have either six or twelve speeds. The stock motor was a 1.5 Hp or 2 speed 1 - 2 Hp. I assume the motors are 1750 RPM 4P

You are also limited as to the maximum spindle RPM, so you do not need a brute of a motor. A 2 Hp motor would be more than adequate, about the only thing would be getting an inverter rated 1200 or 1800 RPM motor. If it is a flat belt it will be limited with regard to Hp delivery, if a spin on chuck than you are limited as to the rate of braking so it doesn't spin off.

VFD's
The Teco L510 is one of the least expensive non-generic type VFD and they work decently. They do not support using an external dynamic braking resistor which is needed for fast stopping so I do not use them for lathes. Teco does make the E510 series which is a bit more full featured and does support an external braking resistor. I am assuming you want single phase input 230VAC. Some commonly used drives in the $250-350 depending on the brand and Hp, the next level up is in the $500+ range and would be overkill for this application. Teco and KB are some of the easier manuals to decipher, in this range/cost I primarily install the WJ200 and Yaskawa drives which are a bit more full featured.

Teco E510 2HP = Teco L510-202-H1-U 3HP = Teco L510-203-H1-U
KB Electronics 2HP = KBDF-27 3HP = KBDF-29
Hitachi WJ200 2HP = WJ200-015LF 3HP = WJ200-022LF
 
The machine in question is a South Bend, it might be a heavy 14 or it might be a 14.5 I have seen them referenced by both. It does have a variable drive, like a snow machine clutch, I guess it is not technically a reeves drive but agian, that is what it is most often referenced as. As near as I can find out there are two auxiliary circuits, one powers a lube pump for the headstock bearings and one powers a little motor that shifts the variable drive.
The main motor is a 3hp 3 phase with a peak amp draw of 10.5 amps.
A RTC would give me full on 3ph power and all features should run as designed, it would work for additional machines in the future, but I would have the extra motor running and the higher cost.
A Static converter won't give me the power because they make you de rate the motor so badly.
A VFD would give me good power, at a much lower cost but is supposed to be only hooked up to the motor so I would have to rig a secondary circuit to power the pump and Vari-drive motor. No big deal except that if the vari-drive is moved without the motor turning it will break it.
So, being as some of you have way more experience than I do with this, what should I do?
 
Cast iron, some of the VFDs you were so kind as to list for me don't look like they would have the rating to run a 3 hp motor. Do I NOT need to match the VFD to the motor?
 
A 3 Hp motor would need a 3 Hp VFD that is rated for the motor rated amps or higher. Given that your motor is 10.5A, reasonable options would be the Teco E510-203-H-U which has an output of 10.5A, the Hitachi WJ200-022 LF is rated for 11A so would also work. Installation is pretty straight forward on either of these, and you do not need an RPC running in the background. What needs to be factored in is you have other 3 phase machines, then an RPC may be a simpler plug and play option. Some of the newer ones are very quiet. Static converters are pretty lame for a lathe.
WJ200-022LF 3HP 2.2kW 230V VFD - Hitachi
E510-203-H-U | Teco Westinghouse | AC Drives

So if you have a variable speed mechanical drive then you would probably set the VFD at some fixed frequency and use the mechanical drive, but also could do some adjustment with the VFD. VFD would be direct wired to the motor, ancillary pump you could bring in a neutral and run it off of 110/120VAC or use a step down transformer.
 
that was along with my thinking, if it is really important to have the safety of the vari drive NOT able to move unless the spindle motor is spinning, I can think of a way to do that as well.
Thanks for the well thought out responses.
 








 
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