RE: 3 phase converting

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Gary Weaver" <gary350@xxxxxxxxxxxxx>




> [Original Message]
> From: Tesla list <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Date: 1/18/2005 2:08:54 PM
> Subject: RE: 3 phase converting
>
> Original poster: "Matthew Carlson" <mjc8804@xxxxxxx>
>
> That is some great info.  We don't much use 3 phase in residential here,
> but it seems to make alot of sense.



I have a work shop behind my house.  There is no 3 phase in a residential
area.   I have a Bridgeport Milling machine, Surface Grinder, Lathe, Air
Compressor, vaccuum pump, Hydraulic Press, Tubing bender, band saw, cut off
saw, table saw, wood planer, Welder, several other 3 phase items all in my
work shop behind the house.  I use to run everything on a static 3 ph
comverter which makes all the equipment run at 2/3 power.  Everything ran
fine except for the surface grinder at 2/3 power.   For awhole I run a
rotor motor but the rotor motor running all day long vibrating and buzzing
drove me nuts.   The rotor motor used a bunch of unnecessary electricity
and runs up my electric bill so I got rid of the rotor.   Now if I need
full power on one of the machines I turn on another motor in the circuit
and use it as the rotor.    3 phase equipment is dirt cheap because no one
wants it at home because they don't know how to make 3ph equipment run on
single phase.

I have a friend that has a 10 hp saw mill.  We connected two 5 hp motors in
parallel.  Sence both motors will run at full power we decided to put a
pully on both motors and run a V belt from each motor to the main drive
shaft.  It works great.  He gets 10 hp using two 5 hp motors.

Gary Weaver




>
>
>
>  >>> "Tesla list" <tesla@xxxxxxxxxx> 1/18/05 8:35:24 AM >>>
> Original poster: "Gary Weaver" <gary350@xxxxxxxxxxxxx>
>
> It is not necessary to build a 3 phase converter that is complicated.
>
> Connect the 2 wires from the 240 volt ac directly to the 3 ph motor
> through
> a double pole switch.  L1 and L2.
>
> Connect a run capacitor between the unused wire of the 3 ph motor to
> one of
> the other motor wires.  L3 to L2.
>
> Connect a start capacitor in parallel with the run capacitor using a
> momentary ON timer relay set to 1 second.  To make it very simple the
> relay
> can be replaced with a normally open push button switch.  Push and hold
> the
> button to start.  When the motor comes up to full speed release the
> button.
>
> The RUN cap should be 30 mfd per horse power.  A 5 hp motor needs 30 x
> 5 or
> 150 mfd.  Gray color oil filled cap.
>
> The Start cap should be 60 mfd per horse power.  A 5 hp motor needs 60
> x 5
> or 300 mfd.  Black color plastic cap.
>
> Then the power is turned on the 2 caps are in the circuit.  The caps
> provide a signal that fools the motor into thinking it is running on 3
> phase so the motor starts.  Once the motor comes up to full speed the
> timer
> drops out the start cap.  The run cap stays in the circuit all the
> time.
> The 3ph motor will run on 2 winding.  With only 2 windings producing
> power
> the motor will run at 2/3 power.   A 3 hp motor will produce 2 hp.
>
> The unused winding of the motor pics up the magnetic field and acts as
> a
> generator.  If you connect another motor in parallel the 2 motors
> gererate
> power to each other and both motors will run at full power.   One motor
> is
> NOT USED and is called the ROTOR motor.  It the rotor motor is a 5 hp
> motor
> it will run 3 other motors of equal HP or a total of about 15 hp so be
> sure
> to use wire large enough in the circuit to handle the current.   The 5
> hp
> rotor motor will also power any combination of motors up to about 15
> hp.
> You can run 15 different motors all 1 hp each on a 5 hp rotor.  You can
> run
> 7 motors all 2 hp each.  You can run one 5 hp, one 3 hp, one 2 hp, one
> 4 hp
> motors.  You can run ten 1 hp motors and one 2 hp and one 3 hp.   Any
> combination up to 3 times the size of the rotor motor.
>
> If you have a work shop with a milling machine, lathe, grinder, air
> compressor, etc. and the largest motor in your shop is a 5 hp then
> build a
> 5 hp motor starter with 2 caps.  Connect all the machines in parallel
> in
> the same circuit.  The 2 caps will start and run any piece of equipment
> you
> have in your shop and make it run at 2/3 power.   Suppose you are using
> the
> surface grinder and 2/3 power is not enough power then turn on the
> milling
> machine and let the motor run but do not use the milling machine.
> The
> milling machine motor will act as the rotor in the circuit causing the
> surface grinder to run at full power.   Any motor in your shop can be
> turned on and used as the rotor.  If you need a rotor motor running all
> the
> time then buy a damaged 3 phase motor from a motor repair shop.  3
> phase
> motors sell as mixed metal at the scrap yard for 2 cents a lbs.  A 5
> hp
> motor new aluminum style will weigh about 50 lbs.  Offer them $5.00
> and
> they will probably sell it.  Some shops pull the copper wire from old
> motors it gets them a better price on copper but they have to pay
> workers
> to do this so there is not much advantage to it unless they have
> workers
> with nothing to do and they have to pay them anyway.   A damaged motor
> with
> a bent shaft, damage keyway, broken mount will work fine for a rotor.
>
> Gary Weaver
>
>
>   > [Original Message]
>   > From: Tesla list <tesla@xxxxxxxxxx>
>   > To: <tesla@xxxxxxxxxx>
>   > Date: 1/17/2005 6:48:39 PM
>   > Subject: 3 phase converting
>   >
>   > Original poster: "Jim Lux" <jimlux@xxxxxxxxxxxxx>
>   >
>   > Ran across the following, which may be of interest:
>   > http://www.airraidsirens.com/proj_3phase.html
>   >
>