Any electrical engineers wanna help me?

#3
I need a wiring diagram for making a 3 phase rotory converter,I have a 10 HP 3ph motor and a 2hp 1ph motor to work with.
What are you going to be starting with this?

The two will start 1 hp down....

Your going to need some oil caps a start cap and a timer would be nice.

Give me more details...
 
#5
i must have missed where he said 480 vac!

a lot of times people have single phase 240
power and want to run a 208/240 3 ph motor,
the vfd is always cheaper and can run off of 240
vac split phase.
 
#6
What are you going to be starting with this?

The two will start 1 hp down....

Your going to need some oil caps a start cap and a timer would be nice.

Give me more details...
I bought a Van Norman model 85 mill,it has a 10 HP spindle motor,I don't need 10 HP to run any tooling that I would ever run. So my plan was to swap it for a 5 HP that I have and use the 10 HP for a converter. The mill also has a 2 HP feed motor and a 1/4 HP coolant pump. All of it is 220/440v. I have 220v single phase in my shop only so a converter would be good for other equipment later on. The expence of swapping out motors gets expensive.
 
#9
The 10 will induce enough third phase to do what ever you need.

5hp spindle and the smaller loads will be fine
Rule of thumb is idler motor is larger than your loads for high torque start up.
Since you are not going to be starting this stuff with under load its not as critical.

Also your other loads contribute current to start anything else.
So your fine.

I looked at the prints the others posted.
All of it works.
But you could use a few more oil caps than indicated for the other 3 phase motors to help.
These add a little phase shift and correct the PF.
When you get it all right ( and this requires a clamp on amp meter to do ) all the motors will run close to name plate and reasonably efficiently.

Start shopping around for wire and stuff to mount this in.
Get borrow a clamp on amp meter and get back to me I'll walk you around what you need to know.

My personal opinion is this can be as simple or complicated as you like.
Simple could just be a rope to pull the idler motor around and get it running with a couple of oil caps to balance things.
Its up to you.
 
#10
the caps NOS mentioned are actually very desirable and probably
well the effort as your project progresses. the guy knows his stuff:thumbsup:

since the L3 voltage is purely induced, not driven by the ac line,
the voltage tends to be a bit lower than the other phases and due
to a thing called "slip" will tend to lag in phase. not a huge issue
but if you are a perfectionist you can get a better balance and
a better power factor with those caps.

i would start with the basic circuit using just the starting cap
and the push button "start" switch. then run your mill motors
and check them for heating. if they run cool you are all set,
if they tend to run hot add the other phase caps and retest.

also, make sure you get the idle motor up to speed before
you turn on your mill motors. these phase adders are not
meant to start up other motors when they are starting.

a quick check to see if your system is working is to get a
digital volt meter, hopefully not one from HF:doah:, and
measure the DC voltage across each phase. if the dc voltage
is low then the voltage and phase 'balance' is good.
 
#11
Thanks guys,I'll be posting more when I get this in place.the move is going to be next weekend so I'll be doing the wiring after that sometime. Thing weights like 6600 pounds so it going to be fun moving it.:doah:
 
#12
Thanks guys,I'll be posting more when I get this in place.the move is going to be next weekend so I'll be doing the wiring after that sometime. Thing weights like 6600 pounds so it going to be fun moving it.:doah:
That will be the hardest part.
Making an add a phase is simple thing, just an old electrician's trick

Borrow that clamp on amp meter from someone if you can however.
Surest way to make things work is with the right tools.
 
#13
I have a clamp on multimeter I think it's an Ideal brand. Is there any volt meters or anything else that I should or could get to make this setup any better? I plan on making this control panel as nice and professional looking as possible.
 
#14
I have a clamp on multimeter I think it's an Ideal brand. Is there any volt meters or anything else that I should or could get to make this setup any better? I plan on making this control panel as nice and professional looking as possible.
No I think that's all you really need

A NEMA size 1 contractor would be nice, a heavy duty relay rated at around 20 or 30 amps would be nice for the start cap.

Timer is optional....

A couple of of good push buttons for a start stop station.

Maybe a 30 amp local disconnect for the whole thing.
You know a complete Size one starter would have most of what you need ( scrap yard thing maybe ).
That leaves finding a heavy enough relay to deal with the start cap.

Something like this would probably work in a pinch from an AC unit
Trane American Standard A C Contactor Relay 2 Pole 30 AMP CTR1582 CTR01582 | eBay

I really have an aversion to selling my hoards of stuff because they allow me to sleep at night safe in the knowledge I can rewire society in my own image after the giant solar flair blows up all the Ipods and VFDs ( you are superposed to do this now :eek:ut: and quietly except I am eccentric ).
HOWEVER I could have a look around downstares and see what I can scare up.
Seems to me I have some NEMA 1 CCL contactors and a couple of 60 amp IEC rated AB contactors.

I probably have everything but the caps.
I don't believe in capacitors or trust them so I don't stock them....
I think they are the devils electronic device.......
Nothing should hold electrons Hostage when the power is turned off!!!!
 
#16
Look hard at it....
Is there anything in there you can't do yourself?

All you need is to wire something up that can roll over on its own and then add some additional caps where needed to your load motors.

But that's my opinion.
What do you want?
That's pre-built all you need is the motor.

Looks like its even using some AC relays and other parts sugested
 
#17
that looks good, it even has the extra caps.

i dont see any fuses or circuit breakers in the box.
make sure you fuse both sides of the 240vac input.

fuses or circuit breakers are fine. for a 10 hp load the input
should be fused at around 60 amps and the wire sized accordingly
at #4 awg copper. i like to size motor wiring at 1 kw per
horsepower. so a 10kw motor load divided by 240 vac
gives you a line current close to 42 amps. because the idler
motor does consume power you need to oversize the
power service by 25 - 50% or 60 amps.

if you are going to only run a 5hp motor you can use
#10 awg and fuse it at 30 amps.

be absolutely sure to check all three phase to phase
voltages to make sure the caps arent causing higher
than normal voltages before you turn on the mill.:thumbsup:
 
#18
Look hard at it....
Is there anything in there you can't do yourself?
not really,but mite save me some fuel looking for all of it.

that looks good, it even has the extra caps.

i dont see any fuses or circuit breakers in the box.
make sure you fuse both sides of the 240vac input.
I was thinking a fused service box on both sides.


If I am correct I should be able to run up to 7.5 HP combined with this set-up.so I mite add an extra service box or a rotary switch for other things.

As this project progresses I'll post up some pictures. Thanks for your all's help on this.:thumbsup:
 

Bikerscum

Active Member
#19
Couple of decades ago I had to set up a couple of spring making machines to run in that company's Mexico shop. I'm guessing the motors were 5hp or maybe a little bigger.

The motors wre 220 3p, the power was 220 1p. I bought some phase "fakers" I guess you'd call them. Cheap, & worked really well. Those machines neved started underr load. There was a button on the box, you pressed & held it down while starting the machine, then let it off once started. The machines ran fine, but I'm guessing at 1/3 the hp?

It really did work well for very little $$

NOS can explain how it works better than me.
 
#20
not really,but mite save me some fuel looking for all of it.


I was thinking a fused service box on both sides.


If I am correct I should be able to run up to 7.5 HP combined with this set-up.so I mite add an extra service box or a rotary switch for other things.

As this project progresses I'll post up some pictures. Thanks for your all's help on this.:thumbsup:
Get the mill and pry anything related too it off the walls and get back to us.

Lets see what you have for parts before you make any snap decisions.

And if you find a size 1 starter kicking around grab that too.

Then its off to the local motor rewind shop or appliance repair for some caps....

I now invoke the MEC act of 2013 ( mexican electrical code lol ) that
states a home owner can improvise a lot of things safely as long as the inspector never looks inside HA HA HA.

This does not have to be complicated or expensive just safe.
Let me know what you have to work with when its home.

In the mean time....
I just went into the tomb of the unknown electrical part to search for two AB 60a 3 phase contactors I know I have ( where though cant seem to find ).
Yours for the asking if you need.
Found a nice little timer...
Some push buttons...

Ya we get you up and running chum no worries.

NOS
 
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