Interact noise

[rkdygert]

Is it normal for an Interact 1 series 1 Bport to make a loud humming noise when the axis drives are engaged? The sound seems to be coming from the servo drive motors themselves. My BOSS 8 squeals with the drives engaged which I understand is normal...but this Interact just doesn't sound right...

-Ryan

[machintek]

Not normal. The interact is a very quiet machine. Does it make the same hum with the drives off? I have seen a loose transformer make this kind of a noise or a transformer in saturation.

George

[rkdygert]

No, it only makes the noise when you engage the axis drives...seems to be when there is power being applied to the axis motors...

There is a slight amount of hum coming from the transformer that supplies the axis drive boards...but that is nothing compared to the hum from the motors themselves. The noise is loudest when the axis motors are stationary.

[gus]

My interact is silent, but my r2c3, which is nearly identical, makes a significant, I would not call it loud, hum when the power enable button is engaged[IOW it shuts up when you hit the EMO] I believe it is actually the main power relay that makes the noise, since it is actively holding in under power

I suppose you could unplug the drive card one at a time to see if it was one of them, but I have never seen that

[rkdygert]

Another question:

I checked the ouput voltage of the transformer that supplies voltage to the drives...the voltage between the ouput terminals (180VAC and 380VAC) and the 0v terminal on the transformer match the designated output within 5VAC. However, the voltage between the output terminals and ground measure 280VAC and 480VAC respectively...the 0v terminal is 100VAC compared to ground.

Could this have anything to do with the motor noise?

The noise ONLY occurs when power is applied to the motors (i.e. drives are engaged) and the noise is DEFINATELY coming from the motors, not transformers or contactors, etc.

Also, the machine is running on a rotary phase converter. Could this have anything to do with it?

-Ryan

[rkdygert]

Here is a recording of the machine. I know it's sort of arbitrary since the noise depends on how high your volume is set, but you can use the sound of the contactor closing (about 5 secs into the clip) to guage how loud it should be.

Initially the machine is running without the drives engaged (first 5 secs)
Then the contactor closes and you are listening to all three drive motors hum as if you were standing in front of the machine. (5secs-20secs)
At 20 secs, I moved the mic closer to the x-axis motor so you can hear how loud it is.
After that, I moved the mic back to the front of the machine and jogged the x-axis back and forth.

Let me know what you think...

[gus]

yup that's loud

the drive cards should be grounded, right at their chassis, so the motors shouldn't be absorbing any voltage differences

are all the motors doing this?

[rkdygert]

Yep, every motor...you can hear each one begin humming when you home each axis and each drive locks on.

Is there a voltage I can measure at the motors to see if it's hi/low? Regarding the high 0v line on the transformer...this doesn't seem correct, whether it's causing the motor noise or not. Can anyone verify if this should be this high and why it would be?

[machintek]

There is a problem. It may be related to the rotary phase converter. I never had one of these on a rotary phase converter. it sounds like the auto-transformers do not like the way you have it set up. 0 volts should be 0 volts with respect to ground. You may have to rearrainge the wiring so the transformers are all attached to the two good phases and the artificial leg only going to the spindle motor.

George

[rkdygert]

George,

Actually I did try this...I wired up the transformers to plain old single phase 220v power and I still get the same problem. Is it possible that the incorrect phase angle of single phase power could have something to do with it? Even with it connected to the phase converter, I had it connected to the two good legs...but they are still 180 degrees apart in phase angle, not 120 like true three phase would be...

I'm not sure if this would have an effect on the output of the transformer...

[gus]

I ran an r2c3 [virtually exact american made machine] on a converter for years.

Is everything grounded internally? there should be big fat grn/yel wires on everything

Is the control head grounded properly? Perhaps a ground loop between the control and the drives

Is it possible someone has cranked the gain up on the drives?

[gus]

I did a quick check on my interact, and there is also a similar, but perhaps opposite voltage offset