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Post by brandon on Feb 15, 2018 4:09:09 GMT
Bruce check my edit to my last post real quick I threw in some more info. You must've posted as I started typing there. Anyway I can't believe it but I didn't even think about grounding the braided sleeve shielding. What's the best way to do that? I couldn't tell from Aforww's video whether or not/how he grounded his. The 3 spindle control wires come near both the Z axis motor and the second Y axis motor. Haven't had any issues whatsoever with X or Y. For isolating signals with a 5-20mA converter are you referring to an opto-isolator? When I was setting up the VFD with GRBL I had an issue where the frequency was flying all over the place and my RPM would fluctuate a lot. I eventually solved this with a capacitor on the VFD side between the PWM signal/ground from the CNC shield. However, I was recommended use of an opto-isolator so I bought a 4 channel one from Amazon but couldn't for the life of me figure out how to wire the thing. I couldn't get any voltage reading through the out-side of it. So I left it at that when the capacitor solved my issue. I was also recommended a resistor between the ground on the CNC shield and the VFD but I haven't put one on mostly because (admittedly) I'm not really sure exactly what it would do to benefit the circuit.
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Post by Bruce on Feb 15, 2018 16:02:25 GMT
I would think a couple zip-ties with a 18AWG or 20AWG wire wrapped around the braided shield should work. Then after I got to thinking about it, you should tie that wire to the VFD ground lug. The 24VDC negative is isolated from true ground usually unless you wire it to ground yourself. For the signal isolation/convertor you want a 0-5vdc input to 4-20mA output. This is the one Alex used: PWM to Analog BOB - amzn.to/2hdt06T . The 4-20mA is immune to electrical noise being a current signal rather than a voltage. I would mount it as close to the CNC Shield control board as possible then run the 4-20mA signal out to the VFD input speed control. Make sure the VFD is set to accept a 4-20mA speed reference signal, rather than the 0-5vdc. There are all kinds of "opto-isolator" type devices. It may be a relay control signal isolator you bought?
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Post by Derek the Admin on Feb 15, 2018 18:15:06 GMT
Great advice Bruce.
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Post by brandon on Feb 16, 2018 1:27:14 GMT
Ok, great! I'll order a signal converter and get it delivered tomorrow. I'll also ground my wire shields, but I assume you mean I should ground them on my VFD's earth ground? It's powered by 110AC so I have live, neutral and earth ground for the main power side, then on the inputs I have a ground for the 0-5v in and a ground for a multi input I believe. Another concern with the VFD I have (one that is of course different than the standard chinese VFD I see in every single setup video) is that I don't seem to see any explicit analog current reference input, just analog voltage. The weird thing though is that in the manual there is a VFD parameter that mentions "4-20mA break time." Here's the manual for my VFD, there are two mentioned in this manual. Mine is the YL620. www.frequency-converter-china.com/uploads/soft/170823/1_2143083921.pdfIf grounding and all else fails (I mean if I can't get a 4-20mA input on this VFD) I may just have to splurge and get a better one. At least the normal Chinese one that comes with 99% of Ebay/Amazon kits has a bunch of support in that there's a bunch of existing forum and video documentation for different uses. The one I got sent really wasn't even the one listed with the spindle, it's different than the one pictured in the Amazon post.
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Post by Bruce on Feb 16, 2018 4:14:46 GMT
From the manual "● It is better to use shielded wire or wire and conduit for power cord and ground the shielded layer or two ends of wire conduit." I would tie it to the input power ground, which then is connected to earth ground. FD or PE depending on which diagram you look at first. Wow that manual stinks. No idea what "4-20mA Break detection time" means unless it is a poor translation for something else. Maybe if the setting is binary for P03.05 (0 or 1) it turns on or off the 4-20mA signal for one of the analog inputs? I found this: ② For control circuit wiring(signal line) ● The signa1 line should be separately laid in a different conduit with the main circuit wire to avoid any possible interference. ● Please use the shielded cable with the sizeof0.52mm for signal lines。 ● Use the contro1 terminals on the control pane1 correctly according to your needs. Not much information to really explain what's going on. Did they use a number 1 for a lower case L there? 1o1
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Post by Derek the Admin on Feb 16, 2018 6:07:10 GMT
We may have to change your forum title to VFD consultant Bruce.
I wonder if the “break detection time” is something similar to slew rate in amplifiers. I didn’t read it in context as you did so I’m just throwing out a halfway educated guess.
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Post by brandon on Feb 16, 2018 23:37:29 GMT
Yeah the manual translations for basically any Chinese VFD is beyond awful. It basically forced me to just play with settings just to get external control to work in the first place. The way it words it makes it seem like you set it up one way but then it doesn't work that way lol.
I have a few things to ground and mess with, so hopefully I'll be back with good news.
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Post by brandon on Feb 17, 2018 3:13:55 GMT
Alrighty, poor update incoming. So there seems to be no 4-20mA in on my VFD (and I couldn't actually get that converter to output a minimum of 4mA anyway, just 0-20). No clue why there's even a mention of 4-20mA break time in the manual. Then there's the next thing. The VFD likes to randomly shut off my spindle while it's running all of a sudden. It seems to happen at ~350hz or so but I've had it happen in different places. I've had it run on 24k rpm before but it just shuts off now giving me Er.04. Whiiich of course has a beyond extremely vague description in the manual. Actually on the online manual it literally says IPM, send for repair. In my physical manual it gives a list of possible things, none of which make any sense. Basically tells me there is probably a motor short, a cooling issue, or some other arbitrary issue which shouldn't possibly exist within my setup.
So at this point it's looking like I'm just gonna send this whole set back and grab a different one with either a VFD that has actual documentation, or one that's an actual Huanyang that there are TONS of YouTube videos about. Also I'll make sure it's actually got a 4-20mA in lol.
My amazing luck seems to be coming to the light haha.
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Post by Bruce on Feb 17, 2018 4:04:14 GMT
Sorry for this trouble Brandon. I've been looking at these crazy VFD/spindle combos and haven't actually pulled the trigger due to this issue of poor documentation and support. I agree the Huanyang looks more promising. Let us know how it works out.
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Post by brandon on Feb 17, 2018 4:22:07 GMT
No worries I really appreciate all the help thus far though. Hopefully the one that I just ordered pulls through for me. At least this time around I'll have an idea on the parameters and how to wire it.
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Post by Bruce on Feb 17, 2018 5:00:38 GMT
I found and downloaded the manual for the Teco Westinghouse L510 that Alex has in his build and it's very good. 152 total pages all in decipherable english.
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