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Single phase to 3 phase conversion on Modern GH1440W lathe
- Thread starter John Conroy
- Start date
Thanks guys, I'll pass along your condolances to my daughter Erin and her husband Cam.
Well it seems like I accomplished very little today. I think the most stressful step is done, pulling out all the original wiring. For that I had to move the machine away from the wall so I got a chance to use the skates I built months ago. They worked well, I used some plastic bondo spreaders for wedges to keep it from rolling too far as my floor is quite sloped.
Power comes into the machine at the junction block on the left, then to the red switch on the right, then to the controls. I intend to have power from the switch feed the VFD and the original switches for forward/reverse, jog, chuck and door safety switches. This will eliminate all the original contactors and controls.
More to come tomorrow.
Power comes into the machine at the junction block on the left, then to the red switch on the right, then to the controls. I intend to have power from the switch feed the VFD and the original switches for forward/reverse, jog, chuck and door safety switches. This will eliminate all the original contactors and controls.
More to come tomorrow.
Today I messed around bench testing the VFD operation. With the motor and vfd on the bench I temporarily wired the single phase 240 to the vfd and connected the 3 phase motor output leads to the motor using some of the scrap wiring I removed from the lathe yesterday. The 5Kohm potentiometer I ordered from Amazon arrived this morning so I also wired it as well as the forward and reverse switches and the jog button and configured the vfd to accept those remote inputs. The Teco L510 vfd comes with a 152 page manual which is very good ( light years better than the Huanyang vfd manual) but it takes alot of reading to figure out which setting parameters to use.I think I've got the hang of it now and I have most of the basic settings the way I want them. I have used 3 of the 5 available switch inputs for forard, reverse and jog. Tomorrow I will use the last 2 for the safety switches. The chuck guard, emergency stop and gear cover door switches will be connected to the same input and will trigger a stop with dynamic braking(stop the chuck in 3 seconds from 1800 rpm). The last input will be for the brake pedal switch which will trigger a coast down stop, you can't use mechanical and dynamic braking at the same time. I shot a short video of running it through it's paces just before quitting for the day. The motor is so smooth and quiet I didn't think it was going 1800 rpm that it's rated for so I wrapped black duct tape around the pulley and used a piece of foil to trigger my photo tach. You can see in the video that it is right on the money for speed.
John, re the dynamic braking, is the 3 secs stop from 1800 rpm kind of a safe stock mode power absorption thing? In other words, if you were only doing 900 rpm could the stop time be reduced to 1.5 secs etc. or does it not work that way? When do those big surge/brake resistors (or whatever they are called) come into play like when you see guys threading to a shoulder & it looks almost instant?
Anyways, looking good!
Anyways, looking good!
Peter, you can set the dynamic braking to what ever amount of time you want. The settings are proportional as you thought. If you set it for 3 seconds at 60hz it will stop in 1.5 seconds at 30hz or .75 seconds at 15hz. If you stop,it too fast the counter emf generated by the motor can cause more cuŕent flow back into the vfd than it can handle and cause an over current error so you have to try different settings to see what will work for your machine. The mass of the chuck and parts held in it have a huge effect. Some vfd's have provisions to connect an external braking resistor to help shed the current but these small Teco ones have an internal braking resistor only. You have to read the manual closely to find that only the 460 volt models allow and external one. The same goes for accelleration times. Heavy chucks and fast accelleration can cause over current errors. If you watch Clough42's series of videos he demonstrates those error situations.
John, there is a way to fix the whistle noise. There are 2 parameter settings to change but my notes are out in the shop so I will post them tomorrow. They are covered in Clough42's video series also. I noted them while watching because my Hyanyang does it too and I'm hoping it has the same settings.
If you turn the volume up in the video you can hear a little of the chirpy noise during dynamic braking. You can see at the end it was at 60hz forward and I switched to reverse while it was still at full speed. It stopped and accellerated to 60hz in reverse in 6 seconds. Something you could never do with a single phase motor.
John, there is a way to fix the whistle noise. There are 2 parameter settings to change but my notes are out in the shop so I will post them tomorrow. They are covered in Clough42's video series also. I noted them while watching because my Hyanyang does it too and I'm hoping it has the same settings.
If you turn the volume up in the video you can hear a little of the chirpy noise during dynamic braking. You can see at the end it was at 60hz forward and I switched to reverse while it was still at full speed. It stopped and accellerated to 60hz in reverse in 6 seconds. Something you could never do with a single phase motor.
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The 3 setting parameters Clough42 adjusted to reduce the whistle/chirp noise and improve motor smoothness are:
Parameter 00-00 "Control Method" should be set to 1 for "SLV Mode" (sensorless vector)
Paramter 11-01 "Carrier Frequency" is set at 5Khz from the factory, if you set it to the maximum 16Khz to noise will be nearly out of the human hearing range so you will barely hear it.
Parameter 11-02 "Carrier Mode Selection" should be set to 0 for 3 phase PWM. For some reason the factory default setting is 1 for 2 phase PWM
In the video I have already set the Carrier Frequency to 16Khz and changed the Control Method to SLV but forgot about Carrier Mode Selection. I will change that this morning and see if it gets rid of the slight roughness in the middle frequency range.
Teco-Westinghouse sells the same motor as mine in a 3600 rpm version (PDH3400 is 1800 rpm qnd PDH3200 is 3600 rpm) and my motor data sheet says the motor can run up to 120HZ so theoretically I could increase the maximum run frequency but for now I'm going to leave it at 60HZ max to prevent damage to the lathe gearbox. The lathe has 8 speeds from the factory and the 2 highest are 1200 and 1800 rpm, a huge gap. Now with the gear box set in the 1800 rpm position I will be able to get 900 rpm at 30HZ, 1200 rpm at 45HZ or basically any rpm between 1 and 1800 I want. I can hardly wait to try it out.
Today I am going to work on the VFD enclosure and maybe get some of the final wiring installed.
Parameter 00-00 "Control Method" should be set to 1 for "SLV Mode" (sensorless vector)
Paramter 11-01 "Carrier Frequency" is set at 5Khz from the factory, if you set it to the maximum 16Khz to noise will be nearly out of the human hearing range so you will barely hear it.
Parameter 11-02 "Carrier Mode Selection" should be set to 0 for 3 phase PWM. For some reason the factory default setting is 1 for 2 phase PWM
In the video I have already set the Carrier Frequency to 16Khz and changed the Control Method to SLV but forgot about Carrier Mode Selection. I will change that this morning and see if it gets rid of the slight roughness in the middle frequency range.
Teco-Westinghouse sells the same motor as mine in a 3600 rpm version (PDH3400 is 1800 rpm qnd PDH3200 is 3600 rpm) and my motor data sheet says the motor can run up to 120HZ so theoretically I could increase the maximum run frequency but for now I'm going to leave it at 60HZ max to prevent damage to the lathe gearbox. The lathe has 8 speeds from the factory and the 2 highest are 1200 and 1800 rpm, a huge gap. Now with the gear box set in the 1800 rpm position I will be able to get 900 rpm at 30HZ, 1200 rpm at 45HZ or basically any rpm between 1 and 1800 I want. I can hardly wait to try it out.
Today I am going to work on the VFD enclosure and maybe get some of the final wiring installed.
I’ve adjusted the carrier frequency on a huangyang to eliminate a whistle on a 7.5 hp motor as well.
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Sent from my iPad using Tapatalk
Dabbler
ersatz engineer
@John Conroy - that's it! I didn't change from 2 phase PWM to 3 Phase PWM... that would account for the whine! I haven't noticed too much loss of torque, but I'm sure it is less also! thanks for the help!
I was thinking I would be able to keep the wiring dead simple like my mill VFD but the further I go with this project the more complex it becomes. I spent the whole day removing the 5 original contactors and the 240-120-24 volt transformer and it's fuses, then re configuring the wiring to include only the main contactor, the transformer and the fuses for the 120 and 24 volt busses. I ran all the wiring for the inputs needed to include all the safety features that came with the lathe. That will include and emergency stop switch, a chuck guard switch, a gear cover door switch and a brake pedal switch. All these switches were configured as normally closed. I reconfigured all except the chuck guard to be normally open as it is easier to set up the vfd for them that way. I will post pictures of all that tomorrow.
I also got the new motor installed and the belt tension adjusted. I turned the wire box on the motor 90 degrees so the wires protrude toward the front of the motor instead of straight down. I ran into a small problem along the way, the motor wire box sticks out further than the old motor and will require some modification to be made to the rear motor cover. Just a little sheet metal work and I also going to add a cooling fan to the motor compartment. When the motor is operating at reduced frequency it may need some help moving air as it will be turning slower.
I also got the new motor installed and the belt tension adjusted. I turned the wire box on the motor 90 degrees so the wires protrude toward the front of the motor instead of straight down. I ran into a small problem along the way, the motor wire box sticks out further than the old motor and will require some modification to be made to the rear motor cover. Just a little sheet metal work and I also going to add a cooling fan to the motor compartment. When the motor is operating at reduced frequency it may need some help moving air as it will be turning slower.
Step by step, coming along!
- does the new motor have the classic grill on the cover end with its own fan inside? Which way does air blow normally?
- I thought I read somewhere that the jog switch itself is special on a regular 2-phase motor, but there was more to the circuit than the equivalent of a short duration switch so somehow be easier on the motor. But now I've had start capacitor issues cross my radar I can't even visualize how jog is working in conjunction with those given the short duration. More known unknowns LOL. Anyways, how does jog factor into a VFD driven motor?
- does the new motor have the classic grill on the cover end with its own fan inside? Which way does air blow normally?
- I thought I read somewhere that the jog switch itself is special on a regular 2-phase motor, but there was more to the circuit than the equivalent of a short duration switch so somehow be easier on the motor. But now I've had start capacitor issues cross my radar I can't even visualize how jog is working in conjunction with those given the short duration. More known unknowns LOL. Anyways, how does jog factor into a VFD driven motor?
The new motor has the fan in the same place but the shroud is about 15 lbs of cast iron. Air is drawn in from the rear and forced out over the cooling fins. The jog function on my single phase motor was basically the same as forward speed for as,long as you hold the button. With a vfd you can set if up however you want, the default is forward at 25HZ with 2 second accelleration time.I am going to leave it like that for now. I have my mill set up to jog in forward or reverse at 15HZ.
That's right, there are 5 switch input terminals on this VFD and you can select a function for each of them.
In my case I have set parameter 03-00 to 0 and 03-01 is set to 1, those are the factory forward/reverse switches that are operated by the giant lever on the apron.
Parameter 03-02 is set to 6 and in the chart you can see thhat I can then go and set parameter 00-18 to 00-20 to define the conditions for "jog forward" which is switch S3 the factory jog button momentary switch.
I have the E-stop switch hard wired to turn off the main contactor which will remove power to the VFD.
Which means I still have parameters S4 and S5 avaiable and I plan to connect the chuck guard switch and gear cover door switch to S4 and set the paramater to 14 for rapid stop so if either switch changes states the motor will stop with dynamic braking.
Last I will connect the foot brake switch to S5 and set the parameter to 15 for a coast to stop (no dynamic braking) so the mechanical brake is not fighting with the electronic braking.
I hope that all makes sense, I have been reading the manual so much that my brain has gone fuzzy.
In my case I have set parameter 03-00 to 0 and 03-01 is set to 1, those are the factory forward/reverse switches that are operated by the giant lever on the apron.
Parameter 03-02 is set to 6 and in the chart you can see thhat I can then go and set parameter 00-18 to 00-20 to define the conditions for "jog forward" which is switch S3 the factory jog button momentary switch.
I have the E-stop switch hard wired to turn off the main contactor which will remove power to the VFD.
Which means I still have parameters S4 and S5 avaiable and I plan to connect the chuck guard switch and gear cover door switch to S4 and set the paramater to 14 for rapid stop so if either switch changes states the motor will stop with dynamic braking.
Last I will connect the foot brake switch to S5 and set the parameter to 15 for a coast to stop (no dynamic braking) so the mechanical brake is not fighting with the electronic braking.
I hope that all makes sense, I have been reading the manual so much that my brain has gone fuzzy.