[AMPS] 3 phase transforers and single phase
Mike Sawyer
kc4slk@csrlink.net
Sat, 21 Apr 2001 19:56:45 -0400
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I always thought that W.W. Grainger had a device that would take 220 =
2=C6 and convert it to 3=C6. It was like a converter of some sort and =
small machine shops would use them just for the purpose of converting =
2=C6 to 3. They weren't expensive either.
My nickels worth of free advice.
Mike(y)
W3SLK
----- Original Message -----=20
From: "Jim Smith" <jimsmith@bigvalley.net>
To: <amps@contesting.com>
Sent: Saturday, April 21, 2001 7:32 PM
Subject: Re: [AMPS] 3 phase transforers and single phase
The single phase you are feeding to the motor has 2 sine waves 180
degrees out of phase with each other. Three phase is supposed to have =
three
sine waves 120 degrees out of phase with each other. If you are =
generating a
third phase , there is no place in the 360 degree cycle to squeeze in
another sine wave. You are going to end up with some really dirty power.
The lathe may be able to deal with the dirty power, but you are =
creating
a problem for the rest of the circuits in the home, the utility, and =
your
neighbors. This situation is likely to create problems with phase shift,
cycle instability, transients, overloaded neutral conductors, and
overheating.
If the utility finds the source of their problems, they are likely =
to
pull your meter to protect themselves, and their customers.
Jim Smith, KQ6UV
----- Original Message -----
From: "jeff millar" <jeff@wa1hco.mv.com>
To: "Peter Chadwick" <Peter_Chadwick@mitel.com>; <amps@contesting.com>;
"'William Fuqua'" <Wlfuqu00@pop.uky.edu>
Sent: Thursday, April 19, 2001 6:02 PM
Subject: Re: [AMPS] 3 phase transforers and single phase
>
> I have an old metal lathe with a three phase motor. In order to get =
three
> phase power to drive the motor I got a 5 HP three phase motor from the
junk
> yard. I connected 240 across two of the phases and it generates the =
third
> phase just because it's spinning. It doesn't want to start by itself, =
it
> just sits there humming and smelling very hot. To start it, I just =
turn
on
> the power and give the shaft a flip with my foot and it takes off. If =
you
> need more power, just connect multiple motors in parallel. When I =
start
or
> reverse the lathe, the motor on the floor hums louder and jumps around =
a
> bit...very cool..
>
> The voltage generated by the third phase runs a bit less than the the
other
> two. Probably not a problem in practice. This trick should work very =
well
> to generate three phase power for transformers and rectifier systems.
>
> jeff, wa1hco
--
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Submissions: amps@contesting.com
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<DIV><FONT color=3D#000000>I always thought that W.W. Grainger had a =
device that=20
would take 220 2<FONT face=3DSymbol>=C6</FONT> and convert it to 3<FONT=20
face=3DSymbol>=C6</FONT><FONT face=3D"Times New Roman">. It was like a =
converter of=20
some sort and small machine shops would use them just for the purpose of =
converting 2<FONT face=3DSymbol>=C6</FONT></FONT><FONT face=3D"Times New =
Roman"> to 3.=20
They weren't expensive either.</FONT></FONT></DIV>
<DIV><FONT color=3D#000000><FONT face=3D"Times New Roman">My nickels =
worth of free=20
advice.</FONT></FONT></DIV>
<DIV><FONT color=3D#000000><FONT face=3D"Times New =
Roman">Mike(y)<BR>W3SLK<BR>-----=20
Original Message ----- <BR>From: "Jim Smith"=20
<jimsmith@bigvalley.net><BR>To: =
<amps@contesting.com><BR>Sent:=20
Saturday, April 21, 2001 7:32 PM<BR>Subject: Re: [AMPS] 3 phase =
transforers and=20
single phase<BR><BR><BR><BR> The single phase you are =
feeding=20
to the motor has 2 sine waves 180<BR>degrees out of phase with each =
other. Three=20
phase is supposed to have three<BR>sine waves 120 degrees out of phase =
with each=20
other. If you are generating a<BR>third phase , there is no place in the =
360=20
degree cycle to squeeze in<BR>another sine wave. You are going to end up =
with=20
some really dirty power.<BR> The lathe may be able to =
deal=20
with the dirty power, but you are creating<BR>a problem for the rest of =
the=20
circuits in the home, the utility, and your<BR>neighbors. This situation =
is=20
likely to create problems with phase shift,<BR>cycle instability, =
transients,=20
overloaded neutral conductors, and<BR>overheating.<BR> =
If the=20
utility finds the source of their problems, they are likely to<BR>pull =
your=20
meter to protect themselves, and their customers.<BR>Jim Smith,=20
KQ6UV<BR><BR>----- Original Message -----<BR>From: "jeff millar"=20
<jeff@wa1hco.mv.com><BR>To: "Peter Chadwick"=20
<Peter_Chadwick@mitel.com>; =
<amps@contesting.com>;<BR>"'William=20
Fuqua'" <Wlfuqu00@pop.uky.edu><BR>Sent: Thursday, April 19, 2001 =
6:02=20
PM<BR>Subject: Re: [AMPS] 3 phase transforers and single=20
phase<BR><BR><BR>><BR>> I have an old metal lathe with a three =
phase=20
motor. In order to get three<BR>> phase power to drive the =
motor I got=20
a 5 HP three phase motor from the<BR>junk<BR>> yard. I =
connected 240=20
across two of the phases and it generates the third<BR>> phase just =
because=20
it's spinning. It doesn't want to start by itself, it<BR>> just =
sits=20
there humming and smelling very hot. To start it, I just=20
turn<BR>on<BR>> the power and give the shaft a flip with my foot and =
it takes=20
off. If you<BR>> need more power, just connect multiple motors =
in=20
parallel. When I start<BR>or<BR>> reverse the lathe, the motor =
on the=20
floor hums louder and jumps around a<BR>> bit...very =
cool..<BR>><BR>>=20
The voltage generated by the third phase runs a bit less than the=20
the<BR>other<BR>> two. Probably not a problem in practice. This =
trick=20
should work very well<BR>> to generate three phase power for =
transformers and=20
rectifier systems.<BR>><BR>> jeff, =
wa1hco<BR><BR><BR><BR><BR><BR>--<BR>FAQ=20
on=20
WWW: &nb=
sp; =20
http://www.contesting.com/FAQ/amps<BR>Submissions:  =
; =20
amps@contesting.com<BR>Administrative requests: =20
amps-REQUEST@contesting.com<BR>Problems: &nb=
sp; =20
owner-amps@contesting.com</FONT></FONT></DIV></BODY></HTML>
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Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com