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Re: 15kVA 12.6kV pole pig (fwd)

---------- Forwarded message ----------
Date: Tue, 19 Jun 2007 04:59:26 -0400
From: timjroche@xxxxxxx
To: tesla@xxxxxxxxxx
Subject: Re: 15kVA  12.6kV pole pig (fwd)



I spent the past two days searching the archives (I'm sure I didn't
scratch the surface) and from what I gather to cut a core or not to is
based on availability to you of big variacs and like always personal
experience and personal design of TC. I acquired a 3 stack of variacs that
are 8" diameter and wound with 12 AWG. they were NOS, I took them out of
there original box. unfortunately the model # is so old that there is no
info on the web. the name plate is blank. I had 2 different electronic
stores try to cross ref with no results. so I am using them as a
adjustable ballast on the 15kVA pole pig now instead of the original
setup I had which is a 1156D. there is a surplus store near me going out
of business and giving away 1156D variacs for $150. CHEAP.  1156D's are
rated 10kVA at 120 VAC. my question is, from my understanding, usually the
wire gage determines current. what makes a variac voltage limits? the
inductance? so that when mains voltage is put across it, it does not see
it as a short? is using two 1156Ds stacked for voltage control with 220
VAC RMS mains not a good idea? variacs are built to run at name plate
current but what about voltage? I have only one other experience with over
voltage of a variac. it was a small 120 VAC 3 Amp and when I put 220
across it, it would blow the breaker. but 1156D are one of the biggest on
market. anyone  have any thoughts???


-----Original Message-----
From: Tesla list <tesla@xxxxxxxxxx>
To: tesla@xxxxxxxxxx
Sent: Sat, 16 Jun 2007 8:37 am
Subject: Re: 15kVA 12.6kV pole pig (fwd)




--------- Forwarded message ----------
ate: Sat, 16 Jun 2007 09:06:06 -0700 (PDT)
rom: J. Aaron Holmes <jaholmes@xxxxxxxxxxxxxxxxxx>
o: Tesla list <tesla@xxxxxxxxxx>
ubject: Re: 15kVA  12.6kV pole pig (fwd)

'm wondering if you're just overpowering your RSG. 
n general, going from 5kVA to 15kVA by just adding a
igger transformer and a bigger capacitor is going to
e problematic; other things need to get bigger too. 
 small-diameter RSG is not going to cut it at pig
owers without help (e.g., series static gap, air
last, etc.)
--- Tesla list <tesla@xxxxxxxxxx> wrote:
> 
 ---------- Forwarded message ----------
 Date: Sat, 16 Jun 2007 10:28:24 -0400
 From: timjroche@xxxxxxx
 To: tesla@xxxxxxxxxx
 Subject: Re: 15kVA  12.6kV pole pig (fwd)
 
 
 david,
 
 
    yes, i am sorry, it is Tim, thank you.
 according to the factory
 nameplate, it is a 120/240 LV. FYI - HV has a 5
 position switch for
 incramental voltages from 12,600 down to 10,500 VAC.
 
 -----Original Message-----
 From: Tesla list <tesla@xxxxxxxxxx>
 To: tesla@xxxxxxxxxx
 Sent: Sat, 16 Jun 2007 6:40 am
 Subject: Re: 15kVA 12.6kV pole pig (fwd)
 
 
 
 
 
 --------- Forwarded message ----------
 ate: Sat, 16 Jun 2007 14:08:31 +0000
 rom: David Rieben <drieben@xxxxxxxxxxx>
 o: Tesla list <tesla@xxxxxxxxxx>
 c: drieben@xxxxxxxxxxx
 ubject: Re: 15kVA  12.6kV pole pig (fwd)
 Hi , is it Tim?
 Are you sure that your newly aquired pole
 transformer isn't rated for 240/
 80 on its low voltage terminals instead of 120/240
 since you are getting
 etter performance by center tapping the LV
 terminals?
 
 avid Rieben
 -------------- Original message -------------- 
 rom: "Tesla list" <tesla@xxxxxxxxxx> 
 > 
  ---------- Forwarded message ---------- 
  Date: Sat, 16 Jun 2007 01:57:34 -0400 
  From: timjroche@xxxxxxx 
  To: tesla@xxxxxxxxxx 
  Subject: 15kVA 12.6kV pole pig 
  
  i have recently went from two Westinghouse PT's
 (about 5kVA) to a 15kVA 
  pole XFR. Holy Squirrelly!! i am running SRSG 3600
 RPM 4flying (.5" 
  tung.)/2 station (.5" german silver). 0.1 uf
 hipotronics 70kV RMS tank 
  cap. 
  
  my biggest issue, besides the obvious current
 limiting, is getting the gap 
  to quench. went to 8 pole flying and basically made
 a jacobs ladder around 
  the rotor. like no quench at all. so back to 4
 flying. am i way off or is 
  this a impedance problem on the LV side of pole
 XFR? BTW - i get nothing 
  but 60 cycle hum or saturation using 220 VAC RMS
 across the LV windings. 
  yet if i hook up my 220 VAC RMS with one leg on the
 CT or hooking it up 
  like 110 VAC RMS, i get much better performance.
 for those interested, i 
  was using a 1256 variac as voltage control and a
 1156D as phase ajustment. 
  Now i have put a 3-stack 60 amp inline current
 limit. i first put 220 
  across it and turned the wipers till i was pulling
 40 amp. then put it in 
  series. it is still only a 3 to 4 foot streamer.
 with my PT's, i can get 2 
  -3 streamers 6 to 7 foot long. 
  
  Thoughts? 
  Suggestings? 
  Ideas? 
 

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