3-phase converter construction
Subj: Re: 3-phase current
In a message dated 12/5/98 8:56:45 PM EST, tesla-at-pupman-dot-com writes:
<< Subj: 3-phase current
Date: 12/5/98 8:56:45 PM EST
From: tesla-at-pupman-dot-com (Tesla List)
Original Poster: "Shady M's Hivh Voltage Supply" <hivolt-at-gil-dot-net>
Yea, I'm new here.
My problem is that I just got ahold of a 10KV power supply, and actually
managed to get all 700 pounds of it to my house-- But I've got no way to
power it. Does anyone know the ballpark cost for piping in 3-phase
current, or what they usually charge for branching it in from a place
where it's already installed?
Build a 3-phase converter --- lots cheaper than Edison --
The price here ( Altadena Ca. ) was 1100 $ between poles + a bond to
guarantee minimal monthly usage + a removal fee when done!!
I built a converter from a 25 H.P. 3-phase motor ---
The start caps are two 4800 ufd. -at- 200 VDC (250 VDC Surge ) ,
connected back to back for A.C. application.
+ o-----| |------| |-------o +
select any wire for the third phase ( in this
use # 2 )
between wires 1& 2 ,connect the start cap. through a
relay or knife switch . ---- connect the flux correction caps to the same
wires ( 1 & 2 ) permanently in circuit ----
For high starting currents ,a resistive line can be used to start
the motor . ---- In my case, the start current is in excess of 130 amps !
I have only a 50 amp service ---
The flux slippage correction capacity required was around 700 ufd.
The no-load current without flux correction was 30+ amps,
with correction ,around 3 amps --
No problems running heavy equipment ,including 5 HP air compressor,
hot tank ( 5 HP ) plus lathe,mill ,tig, mig etc.( not all at the same time
however ) :>)