star delta 6 pole 3 phase motor wiring

[ryan2020]

I recently purchased a vertical harrison miling machine, the machine was wired for 400 volts, I connected it up to my 400 volt chinese 2.2kw vfd and the machine would only run in the lower gears and lacked any power in the high gears, I just figured my vfd was crap so I decided to try a hunyang 220 volt vfd of higher kw rating, 4 kw to be precise.
after a struggle I removed the main motor of the machine, the machine was clearly wired for star 400v connection but I also noted the motor was a 6 pole 990rpm motor of heavy construction, there were 6 wires, non of which were labeled as far as I could see, 3 black wires and 3 red wires. the 3 black wires were bolted together for the star connection and the 3 reds left the motor for l1,l2 and l3.
in my lack of wisdom I thought , just change the connection for delta , so with a multimeter set for continuity I isolated 3 pairs of wires with continuity, the coils I thought.
here is where I believe I may have messed up, the u v w wires,
I had no way, well my brain couldnt figure out which was which so in my mind I made a triangle out of the pairs of connected coils and then rotates the connections of the black uvw wires 1 place or 120 degrees and connected these new pairs to my l1,l2,l3.
I connected up my vfd to the 3 selected wires and my motor ran smoothly and at 50 hz it attained the rated rpm as I checked this with a tacho, now not the smartest but this was on a vfd I didnt care for I switched two of the black uvw wires deliberately to make a fault and sure enough the motor wouldn't run or if it did it was rough, so happy with my efforts I reinstalled my motor to my mill and connected it up to my 220 v 4kw huanyang vfd, same if not slightly worse , no power in higher two gears and after much messing about with vfd settings and torque boost settings its still the same and here I am begging your wisdom and guidance, pictures to follow soon thanks for your help!

 

[ryan2020]

A few bad pictures of my woes

 

[ryan2020]

The vfd

 

[ryan2020]

Clearly im neither electrician or artist

 

[mtt.tr]

Just so we are on the same page

Label convention is
U1 u2 v1 v2 w1 w2

No importance to this:
1S are all say reds
And 2s all black

You should join u1-w2 v1-u2 w1-v2

If as above should work.

Confirm the vfd is set to the correct max ampage and correct frequency

 

[ryan2020]

Label convention is
U1 u2 v1 v2 w1 w2

No importance to this:
1S are all say reds
And 2s all black

You should join u1-w2 v1-u2 w1-v2

If as above should work.

Confirm the vfd is set to the correct max ampage and correct frequency

unfortunately my brain couldnt swallow that lol, what i done was find 3 pairs of two that had continuity , then I swapped the 3 black wires one position

 

[ryan2020]

is there any way of checking I made the correct connections by resistance checking the 3 wires coming from the motor? the reason I ask is the motor access is quite terrible and im not convinced the motor is incorrectly wired because it ran so well under no load and indeed under moderate load was perfectly smooth, hmm cant face taking that motor out again

 

[Pete.]

VFD's often have a setting for the number of motor poles. Have you checked that? If your vfd has auto-tuning it should be automatic but you can set it manually.

Here's the Yaskawa parameter for it:

 

[ryan2020]

VFD's often have a setting for the number of motor poles. Have you checked that? If your vfd has auto-tuning it should be automatic but you can set it manually.

Here's the Yaskawa parameter for it:

View attachment 261008

yes I have tried setting for 4 pole and 6 pole

 

[Hopefuldave]

The key parameters are motor rated current and voltage, rated power (if it's configurable), base frequency (50) and base speed - what are these set to?

Does the motor behave as expected withthe belts off, and does the driven pulley turn freely? If there's a lot of excess friction in the high gears it could be sapping most of the motor power - and I've found some machines need a warm-up in low gear to get the oil thin enough for the high gears! Motor multigrade oils are the worst for this...

Dave H. (the other one)

 

[ryan2020]

The key parameters are motor rated current and voltage, rated power (if it's configurable), base frequency (50) and base speed - what are these set to?

Does the motor behave as expected with the belts off, and does the driven pulley turn freely? If there's a lot of excess friction in the high gears it could be sapping most of the motor power - and I've found some machines need a warm-up in low gear to get the oil thin enough for the high gears! Motor multigrade oils are the worst for this...

Dave H. (the other one)

Ive the uuanyang vfd configured for its max output of 11 amps and the frequency is actually set for 100hz currently but Ive tried every other possible configuration I believe, with the belt off the motor behaves impeccably
you are correct the machine has a lot of friction having a heavy gearbox and bevel gear drive saps a lot of power but I know of another user on here who drives the same mill without issue from a vfd

 

[hermetic]

You have 6 wires, and three coils, get a tester or multimeter and find which red wire is connected to which black wire, and you have found a coil! label the ends of the coil A1 and A2, make the red A1 and the black A2. Find the second coil and label the red B1 and the black B2, label the remaining red C1 and black C2. The next problem is to get the coils connected in the correct orientation around the stator, and this is a matter of trial and error . Connect A1 to B2, B1 to C2 and C1 to A2. The motor is now connected in delta. Connect the three connections from the VFD to each junction, take the belts off the machine and try the motor. If it runs smoothly and quietly without humming, you have cracked it. If it does not, reconnect A1 to C2, C1 to B2 and B1 to A2. When you are happy that the motor is smooth and quiet, try with the belts on. You may have to run the mill in low gear till you get the oil warmed up before it will start in the higher gears. The VFD MAY be faulty, but it doesnt surprise me that the VFD does not develop sufficient torque to drive the machine in high gears when cold, and indeed it may never be able to do this.
Phil

 

[tigdlo]

is there any way of checking I made the correct connections by resistance checking the 3 wires coming from the motor?

I'm not 100% this will tell you everything, but it's a start

Check resistance,
L1 - L2
L2 - L3
L1 - L3

L1, L2 and L3 - motor body or earth wire, these should all be open circuit. A multimeter with measure a resistance through you so make sure you are not touching the ends of the probes.


These should all be very close, post the readings.

 

[Hopefuldave]

Ive the uuanyang vfd configured for its max output of 11 amps and the frequency is actually set for 100hz currently but Ive tried every other possible configuration I believe, with the belt off the motor behaves impeccably
you are correct the machine has a lot of friction having a heavy gearbox and bevel gear drive saps a lot of power but I know of another user on here who drives the same mill without issue from a vfd

If you've set base frequency to 100Hz and are running it at 50Hz, it's only delivering half voltage to the motor - they start out with a v/Hz straight-line characteristic and it'll only deliver full volts at the "base frequency" - that might explain it being a bit puffetic!

Dave H. (the other one)

 

[hermetic]

Just looked at your post again, the first VFD stands no chance of starting a 3hp motor, and the second one is just about up to it, trying to start it at 100Hz is not going to work either, you are trying to double the motor speed, try it at 50Hz and let the mill run in low gear for about 30 minutes, then try a higher gear. I have a Harrison Horizontal with a vertical head, but I also have 3 phase! Good luck with it!
Phil

 

[ryan2020]

so l1 to l2 and l2 to l3 all resistances are exactly 3.9 ohms, there is no continuity between any phase and ground

 

[ryan2020]

If you've set base frequency to 100Hz and are running it at 50Hz, it's only delivering half voltage to the motor - they start out with a v/Hz straight-line characteristic and it'll only deliver full volts at the "base frequency" - that might explain it being a bit puffetic!

Dave H. (the other one)

sorry ive probably mis spoke there because these vfds have manny settings for frquency, base frequency is set for 50hz but ive max allowable set to 100, I hope that clarifies things

 

[ryan2020]

Just looked at your post again, the first VFD stands no chance of starting a 3hp motor, and the second one is just about up to it, trying to start it at 100Hz is not going to work either, you are trying to double the motor speed, try it at 50Hz and let the mill run in low gear for about 30 minutes, then try a higher gear. I have a Harrison Horizontal with a vertical head, but I also have 3 phase! Good luck with it!
Phil[/QUOTE
see I had proper 3 phase power and I also have an older harriso horizontal with vertical head 2800 max rpm and the only concern I ever had was not getting hit by swarf chips bouncing off the walls hitting me but the power from these vfds is no comparison whatsoever but honestly my 2.2kw vfd runs the mill equally if not better than my 4 kw vfd so im at a loss, I was never trying to start the mill at 100 hz either sorry for the miss communication, I just went out and ran the mill there in lower gear and yes warmed up fully it can run the mill in its top gear but I used to be able to spin a 2'' shell mill at 2800 rpm and just smash through aluminium etc but even at 2000 rpm this mill wouldnt cut butter with a 2'' shell mill

 

[hermetic]

If you can track down the person on here who runs one on a VFD and find out what he is using, and what it is rated at, that would be a start. I have installed VFD's for other people, but only on small machines, Boxford lathe etc etc, the Harrison does require some grunt to get it of the mark at high speeds!

 

[ryan2020]

If you can track down the person on here who runs one on a VFD and find out what he is using, and what it is rated at, that would be a start. I have installed VFD's for other people, but only on small machines, Boxford lathe etc etc, the Harrison does require some grunt to get it of the mark at high speeds!

my harrison 140 runs off a cheap chinese 400 volt vfd no bother at all, but its only a 1000rpm lathe , I actually tried that vfd also and it too failed to drive this mill