[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: 180 BPS synch? (fwd)
---------- Forwarded message ----------
Date: Mon, 16 Jul 2007 00:00:51 +0000
From: nancylavoie@xxxxxxxxxxx
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: 180 BPS synch? (fwd)
I recently had to sit through an Allen Bradley "training course " on their
line of VFD"s as it pertains to my line of work. While they called it
training it was more like a 5 hour info-mercial. Anyhow, I think you might
be surprised at the assortment of drives they have as well as the
relatively low cost (for industrial equipment anyways). Might want to
check out their website. Wyatt
-------------- Original message --------------
From: "Tesla list" <tesla@xxxxxxxxxx>
>
> ---------- Forwarded message ----------
> Date: Sat, 14 Jul 2007 10:33:14 -0400
> From: Scott Bogard
> To: tesla@xxxxxxxxxx
> Subject: Re: 180 BPS synch? (fwd)
>
> Bart,
> We install PLC systems where I work, but it is all completely over my
> head, as I am just a summer intern, and have not had any training in that
> area (I'm a mechanical engineering major, not electrical). How much did you
> pay for all that equipment, I know the stuff we use isn't cheap.
> Scott Bogard.
>
>
> >From: "Tesla list"
> >To: tesla@xxxxxxxxxx
> >Subject: Re: 180 BPS synch? (fwd)
> >Date: Sat, 14 Jul 2007 06:57:18 -0600 (MDT)
> >
> >
> >---------- Forwarded message ----------
> >Date: Fri, 13 Jul 2007 22:42:47 -0700
> >From: Barton B. Anderson
> >To: Tesla list
> >Subject: Re: 180 BPS synch? (fwd)
> >
> >Hi Scott,
> >
> >My VFD is pretty darn standard. I insert 220 VAC (or 240, whatever)
> >single phase. The output of the VFD is 3-phase which is cabled directly
> >to a 2HP 3-phase motor. The output is 230 VAC 3-phase. T1, T2, T3, and
> >Ground (4-wires). The VFD does happen to be controlled by a PLC, but
> >this is not necessary. The only reason I use a PLC is to incorporate
> >safety's into my control. The VFD outputs an error signal if something
> >freaks out. The PLC detects the error and shuts down the coil. There are
> >a few other misc. features which includes a low voltage dead man switch,
> >cabinet safety's, alarm signals, etc... That's all PLC crap.
> >
> >The VFD itself is wired up to accept a 0 to 10mA signal that controls
> >the speed from 0 to 500 Hz. I have a 10k ohm pot mounted to the control
> >panel which serves to adjust the speed control. In the past, I have also
> >ran the VFD with a binary input for 16 preset speeds. The speeds are
> >simply entered into the VFD with the VFD pushbutton controls ( set the
> >Hz of each speed). The rotary switch then selects a binary input and
> >tells the VFD to run at SP2, SP5, SP10, (whatever). That was fine, but I
> >find the pot variable adjustment the best for coils.
> >
> >I use an Altivar 31 VFD by Telemecanique. Telemecanique was once known
> >as "not the greatest of VFDs". That has changed in the past 4 years. The
> >company actually was revamped. Nowadays, their drives are probably the
> >easiest to use and are now very reliable. Especially the Altivar 31
> >series (versus the old Altivar 28 which was pure Telemecanique of old).
> >
> >3-phase motors are the most efficient of motors and VFD's allow us to
> >use them. They are capable of forward, reverse, and variable speeds.
> >Most elevators use them to get you to floor 99 and down to the basement.
> >Isn't it interesting how smooth elevators are and when they reach a
> >particular floor, you can "feel" them slow to a perfect stop. That is
> >"all VFD" control. But elevators are simply 1 in 1000 applications. When
> >it comes to motor control, 3-phase is industry standard and VFD's are
> >their industry standard control module. In motor control, Allen Bradley
> >is still top of line for VFD's. But the others now are right there with
> >them in capability. The main difference is that industries are tied into
> >a particular breed by the code they write. It would be an expensive task
> >to change over to something else. So, they stick with what they are
> >familiar with. I do the same. I understand that situation completely.
> >
> >Take care,
> >Bart
> >
> >
> >Tesla list wrote:
> >
> > >---------- Forwarded message ----------
> > >Date: Sat, 14 Jul 2007 00:36:54 -0400
> > >From: Scott Bogard
> > >To: tesla@xxxxxxxxxx
> > >Subject: Re: 180 BPS synch? (fwd)
> > >
> > >Bart,
> > > How exactly does your VFD work, is it some kind of PLC controlled
> > >motor? I originally intended to build an asynch, with a variable speed
> > >motor, but my particular motor was not up to the task (it wouldn't keep
> > >turning when the coil was turned on, I still am not absolutely sure why,
> >I
> > >have theories though). It was simply a vacuum cleaner motor attached to
> >a
> > >dimmer switch, worked great when the power to the tank was turned off, it
> > >would rotate between about 100 and 15000 RPM. Your gap sounds like an
> > >experimenters dream gap!
> > >Scott Bogard.
> > >
> > >
> > >
> > >
> > >>From: "Tesla list"
> > >>To: tesla@xxxxxxxxxx
> > >>Subject: Re: 180 BPS synch? (fwd)
> > >>Date: Fri, 13 Jul 2007 22:19:00 -0600 (MDT)
> > >>
> > >>
> > >>---------- Forwarded message ----------
> > >>Date: Fri, 13 Jul 2007 21:03:03 -0700
> > >>From: Barton B. Anderson
> > >>To: Tesla list
> > >>Subject: Re: 180 BPS synch? (fwd)
> > >>
> > >>Hi Scott,
> > >>
> > >>Your welcome. That's a program the newer coilers probably don't know
> > >>about, but it's been around for a lot of years. There was a time when we
> > >>all talked about this. Probably in the old archives somewhere. I
> > >>personally am a 240 bps guy myself if running in sync.
> > >>
> > >>It's difficult to express why. Part of it is the spark channel building
> > >>upon previous ionized streamers, part of it is the smooth running of the
> > >>gap, and part of it is my previous expeditions of looking at the power
> > >>cycle between the 90 degree voltage and current differentials as I
> > >>compared 120 bps, 240 bps, etc.. However, losses were not considered
> > >>during those simulations, so that is also a factor that has to be at
> > >>least considered. In reality, there's not a lot of difference between
> > >>120 and 240 bps. A simple 8 electrode single gap at 1800 rpm disc speed
> > >>does wonders! Those were things I looked at several years ago. Hard to
> > >>remember the details tonight. I was running sync at that time so this
> > >>info was somewhat important to me.
> > >>
> > >>These days, I'm running VFD variable 3-phase. I love it! Probably won't
> > >>go back to a sync gap simply because I love altering the break rate at
> > >>the twist of my wrist (the sound of the sparks and gap is like revving a
> > >>high performance engine!). Hard to express. When I'm rotating the disc
> > >>fast, bystanders start "standing back" just from the sound. Every coil
> > >>has a particular breakrate that produces a 1)smooth running coil and
> > >>2)long sparks. There's no doubt in my mind about that. I've played
> > >>enough with my VFD to realize that situation is real. Lately, the VFD
> > >>has been my favorite toy. The same could be done with a DC motor of
> > >>course, but with the VFD, I have the same effect with high efficiency
> > >>(plus, I can do sync, preset speeds, or whatever I decide, which is why
> > >>it's a favorite of mine). It's not limited to just one aspect of RSG's.
> > >>
> > >>Take care,
> > >>Bart
> > >>
> > >>Tesla list wrote:
> > >>
> > >>
> > >>
> > >>>---------- Forwarded message ----------
> > >>>Date: Fri, 13 Jul 2007 22:56:16 -0400
> > >>>From: Scott Bogard
> > >>>To: tesla@xxxxxxxxxx
> > >>>Subject: Re: 180 BPS synch? (fwd)
> > >>>
> > >>>Bart,
> > >>> Thanks, I see how bad that configuration is, evidently my gut
> > >>>
> > >>>
> > >>instinct
> > >>
> > >>
> > >>>was incorrect. Thanks for the program, it is very neat, I'm sure it
> >will
> > >>>come in handy.
> > >>>Scott Bogard.
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>>From: "Tesla list"
> > >>>>To: tesla@xxxxxxxxxx
> > >>>>Subject: Re: 180 BPS synch? (fwd)
> > >>>>Date: Fri, 13 Jul 2007 20:28:54 -0600 (MDT)
> > >>>>
> > >>>>
> > >>>>---------- Forwarded message ----------
> > >>>>Date: Fri, 13 Jul 2007 18:06:50 -0700
> > >>>>From: Barton B. Anderson
> > >>>>To: Tesla list
> > >>>>Subject: Re: 180 BPS synch? (fwd)
> > >>>>
> > >>>>Hi Scott,
> > >>>>
> > >>>>A 6 electrode 180 Hz firing rate has always been looked at as likely
> >the
> > >>>>worst of all cases. Haven't tried it myself, but there is an old DOS
> > >>>>program (1991) by Robert Jamison you might want to run that looks at
> > >>>>various configurations, and yes, the 6 electrode case is there. It's a
> > >>>>simple .exe file. It's at my web site if you want to download and run.
> > >>>>
> > >>>>http://www.classictesla.com/download/rotjit.zip
> > >>>>
> > >>>>Take care,
> > >>>>Bart
> > >>>>
> > >>>>Tesla list wrote:
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>>---------- Forwarded message ----------
> > >>>>>Date: Thu, 12 Jul 2007 21:19:19 -0400
> > >>>>>From: Scott Bogard
> > >>>>>To: tesla@xxxxxxxxxx
> > >>>>>Subject: RE: 180 BPS synch?
> > >>>>>
> > >>>>>Nobody responded to my message (not even a "yes, it's been done" or a
> > >>>>>
> > >>>>>
> > >>"no
> > >>
> > >>
> > >>>>>
> > >>>>>
> > >>>>it
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>>won't work"), so I'm reposting it on the assumption either nobody got
> > >>>>>
> > >>>>>
> > >>it,
> > >>
> > >>
> > >>>>>
> > >>>>>
> > >>>>or
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>>nobody took the time to read it and respond, thanks.
> > >>>>>Scott Bogard.
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>From: "Tesla list"
> > >>>>>>To: tesla@xxxxxxxxxx
> > >>>>>>Subject: 180 BPS synch? (fwd)
> > >>>>>>Date: Mon, 9 Jul 2007 15:05:02 -0600 (MDT)
> > >>>>>>
> > >>>>>>
> > >>>>>>---------- Forwarded message ----------
> > >>>>>>Date: Mon, 09 Jul 2007 16:31:13 -0400
> > >>>>>>From: Scott Bogard
> > >>>>>>To: tesla@xxxxxxxxxx
> > >>>>>>Subject: 180 BPS synch?
> > >>>>>>
> > >>>>>>Greetings all,
> > >>>>>> I was curious, what would the results be of a synchronous motor
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>(1800
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>>>rpm) being used with 6 electrodes, for 180 BPS. My thinking is that
> > >>>>>>
> > >>>>>>
> > >>the
> > >>
> > >>
> > >>>>>>arc
> > >>>>>>put out would be slightly more random due to uneven firing voltages,
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>like
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>>>an
> > >>>>>>asynch gap, but prevent dangerous resonant rises, due top it's
> >tenancy
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>to
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>>>inevitably repeat a defined patter over and over again (also
> >different
> > >>>>>>"phasing" may effect output, but I don't think it would ever settle
> >on
> > >>>>>>
> > >>>>>>
> > >>a
> > >>
> > >>
> > >>>>>>phase it cannot operate with, or one that would give optimum power).
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>Has
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>>>>anybody tried this, what do you guys think (I just finished building
> >a
> > >>>>>>120/240 BPS sync, so I don't think I will be building another soon,
> > >>>>>>
> > >>>>>>
> > >>but
> > >>
> > >>
> > >>>>>>maybe somebody else can try it). Thanks.
> > >>>>>>Scott Bogard.
> > >>>>>>
> > >>>>>>_________________________________________________________________
> > >>>>>>Need a brain boost? Recharge with a stimulating game. Play now!
> > >>>>>>http://club.live.com/home.aspx?icid=club_hotmailtextlink1
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>_________________________________________________________________
> > >>>>>Local listings, incredible imagery, and driving directions - all in
> >one
> > >>>>>place! http://maps.live.com/?wip=69&FORM=MGAC01
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>
> > >>>>
> > >>>_________________________________________________________________
> > >>>Local listings, incredible imagery, and driving directions - all in one
> > >>>place! http://maps.live.com/?wip=69&FORM=MGAC01
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>
> > >>
> > >
> > >_________________________________________________________________
> > >http://newlivehotmail.com
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
>
> _________________________________________________________________
> Don't get caught with egg on your face. Play Chicktionary!
> http://club.live.com/chicktionary.aspx?icid=chick_hotmailtextlink2
>
>
>