#31
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Hey Paulo,
Thanks for the advice on that but it is not that that is the problem. In an attempt, I sawed off the extra flap to make sure. There is nothing touching the chassis from the other side. I'm also for sure getting 30vac out of both secondaries. I think the problem is that in the US, from the sources I've been going, all they have are half wave rectifiers, yet they say they are full wave. Would that make any difference? When I rectify, I'm only getting 30VDC out of a 30vAC source. I should be getting 42.5vdc. Pulling my hair out! Chris |
#32
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are you measuring that voltage with or without the caps? I think your ripple current is overwhelming your capacitors. if they have arced they may already be damaged.
Have a look at this thread ( post #8 ) http://www.mechmate.com/forums/showt...ight=rectifier |
#33
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All bridge rectifiers are the same: 4 diodes inside and full wave is rectified. I can't see if the connections on bridge are correct, the AC part can be reversed but not the other part. the way you connect the capacitors, your positive is black and negative is green? (black is normally negative on DC). be careful on that if the polarity on capacitors is reversed for long time they can explode.
Positive on bridge must go to positive on capacitors. i'm sorry if it seems to primary... |
#34
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I see 4 wires going to your rectifier from the transformer.
I think this tranformer could do 2 30 volt or one 60 volt if wired series on the output? Also I agree those caps look small. http://www.mechmate.com/forums/showthread.php?t=4057 |
#35
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Specs on that transformer
If your looking for 60 volts out of that transformer you will need to have it wired series I would think not parallel. |
#36
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What motors are you going to run?
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#37
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I am slowly answering my own questions as the coffee kicks in !!!
Is your input voltage 115 or 220? |
#38
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Hi Mike,
My input voltage is 120vac. I parred up the primaries. I could unpair them and hook them into 240 and check. I've done everything else, I am still not getting 1.41x my AC voltage... It's the Avel 620VA Toroidal. I'm only needing the 30v but 20 amps as I want to mount another spindle/plasma later and 4th axis. Chris |
#39
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You may have your input hot (120) on the wrong pairs according to the spec sheet. Also make sure your wall plug is wired correctly. In the US most neutrals as also ground and a commen mistake at the outlet is to switch the wires.
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#40
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I forgot to mention, my machine build is entirely complete.
Control Box Complete, everything is complete except one thing. My motor power supply! So hopefully, I can figure this out so I can get it all moving. I will post pics after I get some sleep. Chris Last edited by litemover; Fri 08 November 2013 at 04:28.. |
#41
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...Chris is trying to break my record build time
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#42
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Chris your output on the rectifier is fine. please read the link I posted above- you are seeing 30 VDC @120hz
you said: When I rectify, I'm only getting 30VDC out of a 30vAC source. I should be getting 42.5vdc. Pulling my hair out! Chris Richards said: ( in the above link...): Depending on the meter that you used, without the capacitors, you would get about 50VDC from a 50VAC transformer because the meter would "see" 120 positive "cycles" per second, assuming North American power source. If you switched the meter to AC, it would show the RMS (Root Mean Square) value of the "ripple", which would be 1/(sqrt 2) or 0.7071 X the peak to peak AC voltage. Many meters, on the DC setting, will also show the "average" DC voltage. However, if you used an oscilloscope, you would see that the sine wave was actually 71 Volts, peak to peak. After the capacitors are installed, almost all of the ripple is eliminated, and a DC meter will read the voltage as 71VDC. The input and output pairs are fine- the dot you see on the wiring diagram indicates the start of each winding. What is the value of the capacitors you have? |
#43
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Thanks John for the advice,
That's a bit reassuring and I'll try it out. I managed to find the bad cap and just hook up the good one. There must be a lot of ripple because after going out of that, it still read 30vdc. I ordered a cap from Digikey, but it won't be here till wed and the local supply companies only have 3300mf. I'm thinking of buying a few of those and wiring them in just to get this thing working. Aside from that, I'm relieved that is the only thing left for me to do. Well, Paint and logos, but that won't be for a while as I have to start cutting. So don't worry Sean, I won't be breaking any records, but I will be cutting Again thanks for the help guys. I'm crossing my fingers that it is the problem and we can work it out. I'm going to add inline, 2 more caps at 3300mf @ 63v until my new caps come from Digikey. Cheers, Chris. |
#44
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AH HA!!! how did you come up with your capacitor value?
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#45
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Ok, well. It's working. You were right John about the caps smoothing out enough to see it. Maybe when I was in NZ and on a 50hz grid my meter could pick up on the unsmoothed DC. That was what was confusing me.
My caps value is 30000mf, 63v. Should cover it I hope. So now everything is working and I'm about to plug it all in and have a go. Crossing fingers Will post photos tonight if I get back early enough. Thanks everyone for the advice, would've been chasing my tail still had it not been for you guy. Cheers, Chris |
#46
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Just got back from the warehouse. Not sure what is going on but my VFD is not working, the electrician just finished wiring up the VFD, but I think he must have wired it 208 because I'm only getting 120v per leg. Hope he didn't damage the VFD. Will try again tomorrow.
All axis are moving fine, spindle is mounted and ready to go. Just missing the VFD.... It's a 3ph VFD> Same ABB as I own in Auckland. Chris |
#47
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208 Volts
208 volts is a combination of two 110 volt legs. There are out of phase so when added together you get the resulting 208 voltage. Can't draw a series of sine waves but if you check google you may see it. Scroll down and see chart.
http://www.electriciantalk.com/f30/e...120-208v-7538/ |
#48
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Will my ABB VFD, which accepts 3phase, accept 208v or does it need a different flavor of 3 phase? I'm measuring 211v between phases and my VFD is not powering up. It is a used VFD, but I've had good luck with those. Any suggestions?
Looking at the rail, it just looks as if he's pulled 3ph from 2 rails of the 3 ph input. I think I will just wire it up myself like I did the 480v in Auckland. Chris |
#49
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My VFD is rated for 3ph 380-480v. My panel says 3ph 240v, It does delta or wye but still says 240v. So I don't think I can run this VFD on this Panel. Doh. That is a bummer. I'm so used to NZ electricity I totally goofed this VFD up stateside...
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#50
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Oops...
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#51
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It's ok, a new 230v 3ph 5hp Mitsubishi is on the way. I hope that will run ok on this panel.
Any friends in EU, Aus, NZ, or other 230v countries need a 7.5kw 3ph ABB VFD in great condition? $340 USD plus shipping. Last edited by litemover; Sat 09 November 2013 at 14:17.. |
#52
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Some photos of the completed build. That's my guy Tony putting the box together.
Control box mounted. All Axis moving, spindle mounted. No VFD yet. Will take some more tomorrow. Last edited by litemover; Sat 09 November 2013 at 17:53.. Reason: Added photos |
#53
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Thats Nice
Can't wait to see what you are making. It's big and massive, WOW!
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#54
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What
What are the red pieces between the yellow electrical connectors?
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#55
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They're just dividers. I got them from automationdirect. Makes partitioning easy.
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#56
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your cable chain looks excessively saggy.
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#57
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The cable I bought was much heavier than the last sort. Alphawire 16Ga with 3 screens. Kind of overkill but I liked the quality. Plus there is a water cooling send and return in there. If I take a couple links out it should be ok.
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#58
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Chris what is the size of your main beams? they look to be around 9" or 10".
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#59
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They are 10"
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#60
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Chris,
I had a 20' long machine with a saggy chain. I added Air, water and lots of copper. To help the chain, I added a sloped cable support from the midline of the machine to the spot just under the motor in the far end parked position. The chain sagged a bit, but could never "break it's bacK". Plus, I found that without out it, I had noticable yaw drag on that side of the machine.....(that near side motor drew about .5 Amp more.) Great looking build. Wish I was in town to help you! Best, Sean |
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