# VFD on stock 2J Head bridgeport 3 phase motor ?



## bobdog (Apr 23, 2017)

Can I use a VFD  on 2J head with stock 3 phase motor on it ?  I know question has been asked but if can be done. How do you wire one and how well does it work. Would like to talk to somebody who has done it.    Thanks Dave


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## Bob Korves (Apr 23, 2017)

Yes.  The power must go from the wall, to the VFD, to the motor.  No switches allowed between VFD and motor.  The existing forward/off/reverse switch can be used as a low voltage control switch on the VFD low voltage side to run the mill.  The existing wiring will need to be changed so it can do that.  It is not a big deal.


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## Jonathans (Apr 23, 2017)

Its an excellent way to power the mill as you will have variable speed if you get a vfd with a pot in it.
If you want to wire through existing wiring that runs through the switch, you'll have to turn the switch on
and remove the switch knob so it cant' be switched cycled.


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## uncle harry (Apr 24, 2017)

bobdog said:


> Can I use a VFD  on 2J head with stock 3 phase motor on it ?  I know question has been asked but if can be done. How do you wire one and how well does it work. Would like to talk to somebody who has done it.    Thanks Dave



I have installed an Automation Direct VFD on my BP knockoff  mill similar to yours.  I made a bracket-enclosure that accommodates the detachable programming console as well as a 3-position fwd/off/rev switch and a detent E-stop.  The head is also a variable pulley style which allows me to achieve high torque at very low speeds. The combination works well for power tapping with larger taps. The 3 position switch and E-stop use the low voltage connections to the VFD.


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## bobdog (Apr 24, 2017)

uncle harry said:


> I have installed an Automation Direct VFD on my BP knockoff  mill similar to yours.  I made a bracket-enclosure that accommodates the detachable programming console as well as a 3-position fwd/off/rev switch and a detent E-stop.  The head is also a variable pulley style which allows me to achieve high torque at very low speeds. The combination works well for power tapping with larger taps. The 3 position switch and E-stop use the low voltage connections to the VFD.


Does anybody have a wiring diagram and what VFD to use and how to wire my drum switch with it so I have reverse. Im not a electrician so anything would help so . I can do this Thanks Dave


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## Ulma Doctor (Apr 24, 2017)

many different VFD's may work on the milling machine.
if you have a VFD already, if you can tell me a model # i'm pretty sure i can find a diagram.
generally speaking it's not difficult to achieve directional control


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## mksj (Apr 24, 2017)

Several possible wiring diagrams attached, I would recommend replacing the drum switch for a 3 way maintained ON-OFF-ON rotation switch and using momentary run commands. Switches that have been previously used for 120/240V switching often arc and the contact resistance can be a problem with the VFD low voltage signal switching. VFD signaling and external speed pot wiring can be 18-22AWG, power and motor wires are sized to the Hp rating (usually 12AWG for input power, 14AWG motor power for a 2-3Hp VFD).  The VFDs usually need some basic programming, unless you use the simple 2 wire control.

A few VFD models to consider, my recommendation would be the Teco N3 or Hitachi NES1-015SB + NES1-OP
Teco 2 HP, 230 Volts, 1 Phase, IP 20, Teco, L510-202-H1-U
http://dealerselectric.com/L510-202-H1-N.asp

Hitachi 2 HP, 230 Volts, 1 Phase, IP 20, Hitachi, NES1-015SB + NES1-OP
http://dealerselectric.com/NES1-015SB-NES1-OP.asp

Teco 2 HP, 230 Volts, 1 Phase, NEMA 1, Teco, N3-202-CS-U
http://dealerselectric.com/N3-202-CS-U.asp


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## killswitch505 (Apr 25, 2017)

Just did a similar upgrade on my lathe a few weeks ago. Everyone gave you solid advice the only problem I can see is if you're gonna use the same motor you have on it now you may have over heating issues if the motor isn't drive rated


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## Bob Korves (Apr 28, 2017)

killswitch505 said:


> Just did a similar upgrade on my lathe a few weeks ago. Everyone gave you solid advice the only problem I can see is if you're gonna use the same motor you have on it now you may have over heating issues if the motor isn't drive rated


There will not be overheating issues unless the motor is run at significant power for a long time at a slower than normal speed, where the existing fan does not move as much air.


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## 4ssss (May 4, 2017)

Bob Korves said:


> Yes.  The power must go from the wall, to the VFD, to the motor.  No switches allowed between VFD and motor.  The existing forward/off/reverse switch can be used as a low voltage control switch on the VFD low voltage side to run the mill.  The existing wiring will need to be changed so it can do that.  It is not a big deal.




That's not correct. You can use the existing switch by wiring the switch into the VFD and programming it to bypass the control. The speed control will not be affected. I just did this on a SB heavy 10.


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## 4ssss (May 4, 2017)

bobdog said:


> Does anybody have a wiring diagram and what VFD to use and how to wire my drum switch with it so I have reverse. Im not a electrician so anything would help so . I can do this Thanks Dave



If you use  a Lenze SMvector the diagram to wire it is on page 34 or 35 of the manual.  There are 3 diagrams, the 1st is a regular drum switch,  the 2nd is a push button forward/reverse/off.  You then just have to program the VFD as it states above the diagram. I believe it's P122 and P128 factor needs to be changed to 1


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## Bob Korves (May 4, 2017)

4ssss said:


> That's not correct. You can use the existing switch by wiring the switch into the VFD and programming it to bypass the control. The speed control will not be affected. I just did this on a SB heavy 10.


I think that is what I said, and I think we agree.  The motor on/off and forward/reverse must be controlled on the low voltage, control side of the VFD, at least when the VFD is powered up.


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## 4ssss (May 4, 2017)

Correct, the VFD can't be used as a phase converter, (although it technically is) but the machine switch can be wired into the VFD to replace the on/off switch on the VFD.  If that's what is meant by the low voltage side.


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## bobdog (May 8, 2017)

I have stock drum switch how do . I wire it into VFD to stock 3 phase motor on Bridgeport ? Do I just come from 110 volt out of wall to drum switch and then to VFD ?  And whats the best quality and value on buying a  VFD ?


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## Dave Paine (May 8, 2017)

bobdog said:


> I have stock drum switch how do . I wire it into VFD to stock 3 phase motor on Bridgeport ? Do I just come from 110 volt out of wall to drum switch and then to VFD ?  And whats the best quality and value on buying a  VFD ?



VFD's are not designed to have the power disconnected by a switch, so you should run the power feed direct to the VFD without a switch.  The VFD needs to perform ON/OFF function in addition to changing the frequency.  VFD's often have 24V terminals which can be wired to external switches for remote ON/OFF.  Hence you could technically run  small gauge 24V wires to/from the drum switch to use this for ON/OFF/Reverse.  The exact wiring depends on the model of VFD you purchase.  Some models have a front panel which can be mounted remote from the VFD to perform ON/OFF/Reverse and frequency change.


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## 4ssss (May 8, 2017)

Power goes from the source to the VFD to the motor. Then you have to wire the drum switch into the VFD and program it. For a Lenze VFD like I use the wiring diagram is found here at the link. Motor wiring is on page 15 and 16 and the switch wiring can be found on page 31. The 1st diagram is for a drum switch, the 2nd is for a 3 button switch.  They then have to be "commissioned" which means programmed by the "P" code found above the diagram.

http://www.actechdrives.com/PDF/AC-Tech/AC-Tech-SMVector-Drive-User-Manual.pdf


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## Bob Korves (May 8, 2017)

I recommend using external control switches rather than the keypad wherever possible with a VFD.  The keypads on the VFD's are sometimes not the highest quality. and with time they can fail, leaving you with a compromised VFD.  The switches can fail entirely (does nothing) or can get oxidized, which will cause it make a poor contact, and those things can get maddening ( and get worse) quickly.  With external switches for the functions you use regularly, they can be mounted in a more convenient location and can be replaced easily and cheaply.


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## uncle harry (May 8, 2017)

Bob Korves said:


> I recommend using external control switches rather than the keypad wherever possible with a VFD.  The keypads on the VFD's are sometimes not the highest quality. and with time they can fail, leaving you with a compromised VFD.  The switches can fail entirely (does nothing) or can get oxidized, which will cause it make a poor contact, and those things can get maddening ( and get worse) quickly.  With external switches for the functions you use regularly, they can be mounted in a more convenient location and can be replaced easily and cheaply.



Yes Bob and I'll add that I do use the remote keypad for my Automation Direct VFDs  but I only use the speed control pot function while operating.  The logic level control inputs are switched with industrial quality units which have robust contacts that wipe away any oxidation problems.   The other strong suggestion I might reiterate (as have many on this thread) is connect the motor to the VFD directly without any switches or other disconnects. The only exception to that, in my opinion, is if one is having a VFD being used for more than one motor. In this case it is VERY important to disconnect the power into the VFD before switching the output to an alternate load.


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