Results 31 to 45 of 96
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15th Jan 2021, 06:32 PM #31Member: Blue and white apron brigade
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15th Jan 2021, 07:09 PM #32Most Valued Member
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I just put a clamp meter on mine.
240v input was 3.9A, the VFD was showing 2.7A
I tried putting the meter on the motor side, but it was showing 10A - obviously not right. It’s only a cheap meter so I’m picking it’s struggling with the VFD output waveform. I had the same issue originally when I tried to measure the voltage with the same meter and had to resort to my analogue meter.
Steve
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15th Jan 2021, 08:41 PM #33Member: Blue and white apron brigade
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To compare those two you need to multiply the 2.7 by SQRT 3 so then it comes to 4.7A?
Unless those VFD display amps are @415V
I tried putting the meter on the motor side, but it was showing 10A - obviously not right. It’s only a cheap meter so I’m picking it’s struggling with the VFD output waveform. I had the same issue originally when I tried to measure the voltage with the same meter and had to resort to my analogue meter.
Steve
I did a bunch of simultaneous current measurements on a VFD powered compressor motor during compressor recharge cycles between 10 and 16A.
I compared the VFD input and output currents using Fluke current clamps and they all agreed within 10% (most within 2%) but few of these measurements came close to the VFD display.
The VFD display currents were usually a lot less than the inout and output currents.
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15th Jan 2021, 09:36 PM #34Senior Member
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- Nov 2007
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- Near Rockhampton
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8th Feb 2021, 11:17 PM #35
Earth connection
I have wired my 2.2 kw ecogoo inverter to a 3 phase motor, however I don't know where to connect the motor's earth wire.
There is no earth terminal with the motor connections, and I can't see any reference to a earth terminal in the manual.
Do I run it to the 240v earth connection? or perhaps a mounting screw on the heatsink?
MarkI've become a tool of my tools.
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9th Feb 2021, 03:29 AM #36
Hello Mark,
Normally the motor, indeed any of the machine metalwork would be earthed to the input mains earth. To be sure I would use a test bulb, not a multimeter, to check that there was not any residual mains voltage on the motor case/frame to earth. I wouldn't use the heatsink screws on the VFD unless there was a specified earth point, and it should be marked as such anyway.Best Regards:
Baron J.
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9th Feb 2021, 07:54 AM #37Most Valued Member
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I’ve run my motor earth to the earth terminal on the 240v/input side.
Would have been nice if there was an earth terminal near the motor ones, but I guess that’s part of the cost compromise
Steve
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13th Feb 2021, 06:33 PM #38I break stuff...
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- Aug 2010
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- Toorloo Arm, VIC
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- 39
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I've discovered that on a 4kw version you don't appear to get any earth terminal at all... Pretty ordinary. Not sure if RCs is the same. Currently on my temporary hookup the earths (motor and 240v input) are attached to the heatsink at the back - not really sure that's actually connected to... anything of use inside the unit, but given it's the only conductive part of the unit you can touch, I guess it fulfills the fault protection requirement.
Running just the headstock, clutch disengaged settles in at about 3.6A on the 240v line, throwing the clutch spikes to 8A as the spindle starts up then drops back to about 6A. I'm sure that will increase a bit once it's got a chuck on and is running the quick change box as well. Rated (3.7kw) motor current is 6.8A per phase at 440v - not actually sure whether the VFD is putting that voltage out or not, but I did set that in the motor parameters. If it's not I think it worked out about 7.2A at 415V. I'm running mine off a 15A outlet, but wouldn't be surprised if under full load it'll draw more than that.
Oh yeah, and with a 7.5sec ramp time, the current draw starts about 1.2A, slowly runs up to 4A when the motor reaches full speed, holds that for a couple of seconds, then drops back to 3.6A. Could probably run a much shorter ramp time and still not get much of an inrush spike, but given I have a clutch, I don't care much.
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15th Feb 2021, 04:09 PM #39Golden Member
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- Sep 2008
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- Riddells Creek, Vic.
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Vector Control Mode.
There are 2 option for Vector control- 0: - Vector Control without PG or 4: - Vector Control with PG, but I can't find any reference to what PG actually stands for in the instructions. Is any one using Vector Control?
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15th Feb 2021, 05:10 PM #40Most Valued Member
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From playing with other brands, I’m pretty sure the PG is when you have speed encoder on the motor for feedback.
I’m not using vector control on my ones at this stage.
Steve
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15th Feb 2021, 06:42 PM #41Senior Member
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- Jan 2012
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- Melbourne
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- 149
PG = pulse generator (encoder)
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16th Feb 2021, 12:26 PM #42Golden Member
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- Riddells Creek, Vic.
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I tried Vector Control Mode but the motor did not like it, there must be more to it than just enabling VCM.
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16th Feb 2021, 01:14 PM #43Most Valued Member
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Did you do an auto tune?
If so was it done before or after setting vector control?
Steve
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16th Feb 2021, 04:40 PM #44Golden Member
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- Riddells Creek, Vic.
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Yes Steve I did do an Auto Tune before setting up Vector mode not after but it works perfectly in V/Hz mode so I will just leave it there.
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16th Feb 2021, 08:46 PM #45Most Valued Member
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Thanks. I was wondering if one needed to be done again after the vector mode was set.
No idea whether that’s the case, but if you HAD done one then it would have ruled it out.
Steve
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