[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [TCML] Terry Filter Caps
I have a safety gap, a lightninng arrestor, a TVSS, and 180 amps worth of EMI's. I also have fast blow fuses feeding the vfd. At this point I think I'm getting kickbacks from my motor leads. I too don't know how to ground the motor frame or shield. I think that's my problem right now. Until I get this figured out, I'm gonna work on my ridilulosly large topload. I recently got 12" x 20' of currugated drainage pipe. Should make for an insane topload. Guess I'm gonna have to dust off my 16" coil form shortly after that.
Please tell me more about your "common mode MOV's" on your motor leads!
Adam
--- On Tue, 8/26/08, FIFTYGUY@xxxxxxx <FIFTYGUY@xxxxxxx> wrote:
> From: FIFTYGUY@xxxxxxx <FIFTYGUY@xxxxxxx>
> Subject: Re: [TCML] Terry Filter Caps
> To: tesla@xxxxxxxxxx
> Date: Tuesday, August 26, 2008, 9:25 PM
> In a message dated 8/26/08 9:57:24 P.M. Eastern Daylight
> Time,
> yurtle_t@xxxxxxxxx writes:
>
> >BTW, I just blew up my second VFD :-(((.
>
> I killed two of my VFD's as well. They were old
> Motortronics units,
> nothing I was too excited about, but they were perfectly
> fine pulls until I used
> them to run the ASRG.
> I thought the first one was on it's way out, since
> it kept tripping its
> upstream MCP on power-up. It worked fine until I started
> tuning the coil and
> getting more power out of it. Gave a nice flash and stopped
> working. Did a
> power cycle and got a *BANG*. The other one (identical)
> didn't trip the MCP, so
> I thought it would do better. Nope, lasted all of 20
> seconds. That's when I
> stuck the SISG under there!
> Autopsy revealed not only was the power module blown,
> but the driver
> IC's were vaporized off the board! At that point I
> swore I wouldn't pay more
> than $50 for a drive that I would sacrifice on the altar of
> Tesla, and I set off
> to improve the transient protection of the control system.
> I built the Terry Filter. I also put common-mode
> MOV's at the jack for
> the cable going out to the RSG motor. I had also run the
> RSG motor cable in
> the same flexible conduit as the two hots from the pig.
> Despite the RSG cable
> shielding, that probably wasn't the best way to do it!
> I bought a *really* cheap VFD. Apparently Dart
> Controls, who makes a lot
> of fractional HP DC drives, did a stint of little
> inverters! Discontinued
> now, and they just don't get more cheaply built than
> this thing! I've got a
> *tiny* Mitsubishi as a back-up, but I'll be darned if
> that Dart hasn't died yet!
> It really does take 1/2 HP to accelerate a 12"
> RSG with a 3/4" G10
> 8-electrode disk to 3600 RPM in 20 seconds. It takes 2/3 of
> that to keep it
> spinning at that speed!
> At least one good thing about running a
> series/parallel Y motor off 240
> is it gives some headroom for transients. Running them off
> 480V with an
> inverter gives little room for noise in normal
> applications - it's usually the
> first few windings that die when the switching spikes burn
> out the insulation.
> I'm still undecided as to how to ground the motor
> frame and cable
> shield, so I've just left them floating. :)
>
> -Phil LaBudde
>
> Center for the Advanced Study of Ballistic Improbabilities
>
>
>
> **************It's only a deal if it's where you
> want to go. Find your travel
> deal here.
> (http://information.travel.aol.com/deals?ncid=aoltrv00050000000047)
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla