Vfd Installed, Lathe Up & Running :)

Not sure how this one is wired in. On my lathe 2 proximity switches are wired in series with the e-stop. An override switch is wired in parallel with the 2 prox switches.

Not nearly as elegant and no braking. But low speed threading stops quickly anyway.
 
Wiring in a proximity stop varies by system and if you use relays. There is also PNP and NPN direct current types depending on if you are switching the power side "P" or the negative side 0V "N". The maximum switched power varies by sensor, usually around 200mA total load. They can be 2, 3 or 4 wire depending on how they are powered and what is switched. They can be shielded, and also vary on how fast they can sense an object. I have been wiring them after the E-Stop in series. There is a momentary bypass switch which is in parallel with the proximity sensors switched leads, this allows one to reverse and back away from the proximity sensor without disengaging the half-nut. This is how I thread all the time, I just find it easier. Wired in after the E-Stop, but before the proximity switch is a small plunger style limit switch which is also mounted on the micrometer stop. This engages after the proximity sensor, and cannot be bypassed. It acts as a second electro-mecahnical safety stop should the sensor fail or the sensor is bypassed and you run the lathe in the wrong direction. Both the the P sensor and the limit safety switch are mechanically attached to the micrometer stop plunger, so the distance can be adjusted.
 
Hi
"a small plunger style limit switch which is also mounted on the micrometer stop. This engages after the proximity sensor, and cannot be bypassed. It acts as a second electro-mecahnical safety stop should the sensor fail or the sensor is bypassed"

I was thinking what if the sensor fails, good idea, have you a wiring diagram very simple, it takes time to sink in, getting old. LOL
jeff
 
Hi Jeff,

Information requested.
P sensor wiring.jpg
 

Attachments

  • Proximity Sensor PFK1-BP-3H with cable and mounting.pdf
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mksj said:
Wiring in a proximity stop varies by system and if you use relays. There is also PNP and NPN direct current types depending on if you are switching the power side "P" or the negative side 0V "N". The maximum switched power varies by sensor, usually around 200mA total load. They can be 2, 3 or 4 wire depending on how they are powered and what is switched. They can be shielded, and also vary on how fast they can sense an object. I have been wiring them after the E-Stop in series. There is a momentary bypass switch which is in parallel with the proximity sensors switched leads, this allows one to reverse and back away from the proximity sensor without disengaging the half-nut. This is how I thread all the time, I just find it easier. Wired in after the E-Stop, but before the proximity switch is a small plunger style limit switch which is also mounted on the micrometer stop. This engages after the proximity sensor, and cannot be bypassed. It acts as a second electro-mecahnical safety stop should the sensor fail or the sensor is bypassed and you run the lathe in the wrong direction. Both the the P sensor and the limit safety switch are mechanically attached to the micrometer stop plunger, so the distance can be adjusted.
Click to expand...


Mike you rock, I am shines new to all of this stuff and you make it seem like child's play. I hope I can pick your brain once I have said up my pennies to get a new lathe.
 
mksj said:
Hi Jeff,

Information requested.
View attachment 127157
Click to expand...

Hi
Thanks Mike but most of it went over my head.
1. does the 24v come from the VFD ???
2. white NC to load, is this back to the VFD or in line with the stop sw. or is the powering a relay or contactor. ???

I get the NC safety stop sw & the prox bypass sw, but is the 24v coming from the D1 or D2 on the VFD.
I can not believe i am so bad at this i used to repair cranes do electrical fault finding, rewires all 3ph, i hate getting old arrrrrrrrrrrrrrrrrrrrrrrrr.

Thanks Jeff
 
The P sensor is inserted after your E-Stop (low voltage DC circuit), just like a limit or kill switch after the E-Stop. This can either be in a relay circuit or in the VFD terminal control circuit. The VFD must be setup so the inputs use "source" logic. What this means is that the input terminals are at 0V (ground) and they are activated by the internal VFD power for these terminals, which is usually 12 or 24V. The default on most VFDs is usually the opposite, which is called "sink" logic. Also note that on some VFDs the power supplied to the logic inputs can be very low, like 20mA. The proximity sensor needs a few mA to operate. I use all relay controls in most of my builds, so the P sensor is connected to the power supply that operates the relays, the relays then switch the VFD inputs. One also needs to be aware that the maximum current that most of these sensors can switch is about 200mA. Since small relays can take around 70mA to turn on, a contactor much more, one needs to design the circuit and indicator lights to take this into account.

A 4 wire P sensor that also has a normally open switch that closes when the P sensor is triggered (black wire in this sensor), this could be used in a 3 wire control system to operate the Stop input command.

Mark
P sensor logic.jpg
 
Mark,

Is there any way you could do a video demonstrating how you thread using the stop feature? I know it's asking a lot but I think it would be very interesting to see.

Dan
 
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