Looking for help for vfd for Boxford

Keep in mind that the VFD output needs to be connected directly to the motor, no switches or anything else between VFD motor output and motor. Otherwise you risk damaging the VFD. You can use the existing switches and contactors on the lathe to control the low voltage side of the VFD.
 
Keep in mind that the VFD output needs to be connected directly to the motor, no switches or anything else between VFD motor output and motor. Otherwise you risk damaging the VFD. You can use the existing switches and contactors on the lathe to control the low voltage side of the VFD.
From what Karl has put forward the estop on off switch along with safety switches etc would supply power to vfd

Then forward reverse swich connected as inputs on vfd without brake

Foot brake just for threading im not sure how this would connect in yet

Then 3 phase output direct to motor.

Im not upto speed with electronics so thats why seeking advice on unit selection that i could acheive these parameters so any input appreciated
 
OK, more than one way to do this.

My first concept would be the Estop circuit as previously outlined to bring in a contactor in front of the VFD.

Then what I will call an "enable' circuit. It will go through the F/off/R switch to the start pushbutton, to the foot switch and then to coil on an enable relay. Push start and this coil will latch closed. kick the foot or turn F/off/R to off and drop this coil. Now use a second set of contacts on this relay and a second set of contact on your F/off/R switch to wire the VFD for forward or reverse. Note this idea needs two contacts on your F/off/R switch and a DPDT relay.

There may be a more clever way to do this.
 
From what Karl has put forward the estop on off switch along with safety switches etc would supply power to vfd

Then forward reverse swich connected as inputs on vfd without brake

Foot brake just for threading im not sure how this would connect in yet

Then 3 phase output direct to motor.

Im not upto speed with electronics so thats why seeking advice on unit selection that i could acheive these parameters so any input appreciated
You seem to understand the picture. The VFD power output needs to go directly to the motor, no switches or other controls in between. Some existing machine switches, especially those mounted on older machines, might have too much resistance at the contacts to reliably operate the VFD. You can check the resistance across the switches and other controls with a VOM (volt/ohm/meter).
 
I do not recommend you use the E-Stop and safety interlocks to kill power to the VFD, if you hit the E-Stop the VFD will often free wheel to a stop, although some can use regenerative power to do a controlled braking. Typically the E-Stop and safety switched are all serially connected to the VFD low voltage input signaling so, would kill power to the run commands. You do not want the forward/reverse switches directly wired the respective VFD low voltage input because the lathe can start if you release the E-Stop or any of the interlocks. Typically what is done is to use two latching relays to for the forward/reverse commands, these are typically 12 or 24VDC. Alternative is to strip out the high voltage to the contactors and use them to switch the low voltage VFD signals. These requires replacing the contactors as the contact resistance is an issue with used ones.

Unclear on what you want the foot brake to do, if you want it to stop the lathe with braking then it just breaks the signaling pathway, but you still need some form of latching relay design so the machine does not restart when you release the brake. I have also designed systems that use momentary buttons for for/stop/rev which some people have preferred. If you have a manual brake, then you want to wire the stop switch to issue a free run command to the VFD so the VFD braking is not over riding the foot brake. You can also program the VFD for different braking rates.

Attached is a control system I designed for the G4003G which uses the WJ200 VFD, the jog circuit would vary based on the VFD. This design uses 3 pole relays, the 3rd pole could be wired to operate a coolant circuit, otherwise 2 pole relay can be used. The relays should use the snap in protection diodes that fit into the relay base to prevent reverse voltage spikes when the relays open.
 

Attachments

  • G4003G WJ200 VFD Schematic with external 24VDC PS Jog 2-19-2018.pdf
    1.2 MB · Views: 9
  • G4003G lathe VFD 3 Relay Control System WJ200 Programming Parameters 2-19-2018..pdf
    2.5 MB · Views: 5
In addition to all the above, you need to configure your motor for 220 volt as indicated on the nameplate if it is not already
Have you considered using a rotary phase converter instead of a VFD? It would eliminate a lot of rewiring
 
OK ask two engineers how to do it, get three answers. I should concede mksj has more expertise in this area.

I do have the 3M corporate safety philosophy on Estop. This circuit must kill the machine NO MATTER WHAT. Some idiot mis-wires or programs something, the machine still dies. Yep, this concept just lets the machine coast to stop on E-stop but you cannot do anything program wise to have it not stop. With this concept Estop is only for an emergency - never push it for normal operation. Then set the Estop when you are done. Now your kid etc. is unlikely to accidently start it up.
 
OK ask two engineers how to do it, get three answers. I should concede mksj has more expertise in this area.

I do have the 3M corporate safety philosophy on Estop. This circuit must kill the machine NO MATTER WHAT. Some idiot mis-wires or programs something, the machine still dies. Yep, this concept just lets the machine coast to stop on E-stop but you cannot do anything program wise to have it not stop. With this concept Estop is only for an emergency - never push it for normal operation. Then set the Estop when you are done. Now your kid etc. is unlikely to accidently start it up.
Yes I have always been in line with thinking Estop is exactly that it kills everything including power in this instance not only to stop rotation but also kill electricity before it kills you I case of electric shock.In the case of emergency you can't always have everything so best scenario is to totally isolate the equipment .
In the picture attached I see the common forward ,reverse , reset connections but what are the others rst spl spm sph below the forward revers conections
 

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Im Feeling rather helpless and stupid i have been reading all the input but my brain is in overload trying to picture wires etc from a conversation in text.Soi came up with this drawing of what my conception is It might be totaly stupid and unpractical but im all for simplicity rather than wires overflowing out of my lathe like spagetti. I know there are other options but this is a start .Will it work and if not what would i need to change in laymans terms please im electricaly thick haha
 

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I'm not sure if you really need a separate contactor- I thought most VFDs have internal latching logic for start, stop, etc
You just provide momentary buttons to the corresponding inputs-?
mark
 
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