WeldingWeb - Welding Community for pros and enthusiasts banner
Cancel
Create thread New Forums

Lincoln vertical bullet welder

1 reading
Jump to Latest
21 - 40 of 57 Posts
#22 ·
Nice reading.
But showed a Dela wound motor and for some reason they will not start on a capacitor.

A rotor phase converter is a three phase motor with a capacitor start.

Some small shops build a motor generator for the third leg not shown.

The vdf is great but price is high.

I do not know why the do manufacturer a electronic phase shift for the third leg.

Dave

52 Ford said:
This link explains methods of running a 3ph motor on single phase.

https://www.electricaltechnology.org/2021/12/run-three-phase-motor-on-single-phase-supply.html

Sent from my Lincoln Buzzbox using Tapatalk
Click to expand...
 
Discussion starter · #23 ·
For the people who havent seen one the AC motor is on the same shaft as the DC generator and this can not be changed, The AC motor is permanently set in delta, I would not attempt to run it on single phase, I have done this in the past with 3 phase motors and its disappointing, I reckon it would run off a vfd but was worried it would damage the VFD, I would need to mod the relay to turn onn when the vfd is turned on.
 
#25 ·
Willie B said:
Gee, I sure wish you'd enlighten me the "easy to convert to single phase". In my mind, nothing easy about it.
Click to expand...
I’ve seen motors that can be wired for 460/230 three phase
or 230 single phase. Not sure if stator has anything unique
about it allowing it to be used on single phase.
When used on 230 single phase,start and run capacitors
and voltage sensing relay are needed and HP of motor is derated.
 
Save
Reply Quote Like Like
#28 ·
I haven't done it. A friend is an electrician & self taught machinist. He uses a rope around the shaft to start a three phase motor on single phase. This is pretty lame power source. He then switches other motors on using the first as power supply. A bare minimum of three three phase motors must be run idling to supply a third phase & ultimately supply the lathe, or mill you hope to supply. He estimated the motor doing the work to produce 1/2 the torque & horsepower it should.

It causes several problems in the loaded motor, is not a perfect system.
 
Save
Reply Quote Like Like
#29 ·
jpump5 said:
I’ve seen motors that can be wired for 460/230 three phase
or 230 single phase. Not sure if stator has anything unique
about it allowing it to be used on single phase.
When used on 230 single phase,start and run capacitors
and voltage sensing relay are needed and HP of motor is derated.
Click to expand...
Never seen such a motor, nor can I wrap my head around the concept. Motors need additional windings to be used on either phase. I can't figure where there would be room inside the motor frame for a second set of windings. Wouldn't be very efficient.
 
Save
Reply Quote Like Like
#30 ·
Back to the basic question can it run off a add a phase or rotary phase maybe if you have a big enough one which goes back to the feasibility it probably runs on 35 to 40 amps so gonna take 60 amps to start it ! So for a short duration you need a lot of amps
can you run it dropping one leg probably but your going to be derated!
Can you add capacitors and etc , etc ,etc , yes maybe but the average guy at home isn’t going to do that the feasibility of it is not there
Feasibility , reliability and the ability to do some of that restricts the average user
I also will bring up one point that all of that brings up questions if the insurance man comes and looks things over
If it was feasible everyone would do it because there are a lot of those old motor Generators around they wouldn’t be going to the junkyard
My point is we shouldn’t be telling people it can be done if you don’t have one sitting in your shop working telling somebody who is new at this that it can be done in theory isn’t the best practice .
 
#31 ·
It just how motors work.
Most do not know single phase capacitor start and or run motors are 2 phase motors.
The capacitor shifts the phase.

Dave

Leogl said:
Well I am not an expert but I am guessing that you have done this and it works so good luck
Click to expand...
 
#33 ·
smithdoor said:
It just how motors work.
Most do not know single phase capacitor start and or run motors are 2 phase motors.
The capacitor shifts the phase.

Dave
Click to expand...
I think you are a little confused. The start winding is very different in induction from the run. It is this fact cures the indecision of which direction to turn. The large induction pulls voltage timing out of alignment with current peak. Energy is wasted in the form of extra heat. Each capacitor serves the same purpose, correcting the timing so voltage & current peak simultaneously. Start winding for torque, run winding for efficiency & motor life.
 
Save
Reply Quote Like Like
#34 ·
You using the capacitors to shift the phase. The start capacitor is only for starting. The oil capacitor is for running to keep power up.
Using capacitors is about 99% efficient and if all you have single phase it works great.

If you three phase use it.

Dave

Willie B said:
I think you are a little confused. The start winding is very different in induction from the run. It is this fact cures the indecision of which direction to turn. The large induction pulls voltage timing out of alignment with current peak. Energy is wasted in the form of extra heat. Each capacitor serves the same purpose, correcting the timing so voltage & current peak simultaneously. Start winding for torque, run winding for efficiency & motor life.
Click to expand...
 
#35 ·
smithdoor said:
You using the capacitors to shift the phase. The start capacitor is only for starting. The oil capacitor is for running to keep power up.
Using capacitors is about 99% efficient and if all you have single phase it works great.

If you three phase use it.

Dave
Click to expand...
Thank you. I will go on using three phase motors on three phase power sources, or in special circumstances, I'll use a phase convertor. In no circumstance will I connect a three phase motor doing a job to a single phase power source.

I commend you for having a secret I never learned in 53 years in the trade. I sure wish you would share your secret.
 
Save
Reply Quote Like Like
#36 ·
I looked while I was at the shop today I have a old Airco { Hornet I think } motor generator it takes 32 amps to run it so 50 amps to start it and it runs at 3500 rpm so like sberry said earlier maybe for a hobby guy the biggest problem with the motor generator is they are very noisy and they only have one purpose and that is to stick weld and they are great to air arc with
 
#37 ·
smithdoor said:
You using the capacitors to shift the phase. The start capacitor is only for starting. The oil capacitor is for running to keep power up.
Using capacitors is about 99% efficient and if all you have single phase it works great.

If you three phase use it.

Dave
Click to expand...
I have not been able to achieve this efficiency with capacitors. No where close. But it does work

Sent from my SM-N975U using Tapatalk
 
#38 ·
It is book numbers.
Motors are about 90 to 96% efficiency at full load.
Transforms are about 94 to 98% efficiency at full load

Dave

neilkingent said:
I have not been able to achieve this efficiency with capacitors. No where close. But it does work

Sent from my SM-N975U using Tapatalk
Click to expand...
 
Discussion starter · #39 ·
I built a 10HP rotory phase converter a long time ago and its not very good, it has a capacitor start
, you switch it on and hold down a button until the 10hp idol motor is at speed, I was running a 2.2KW motor but it would bog down and stall some times.
 
#40 ·
View attachment 233C3A94-F3F3-41EA-A42C-9D854B871506.jpg
Here’s one configuration I found yesterday for running a
three phase motor on single phase. No capacitors on this
one.
Not exactly sure how that start relay works. I’m thinking
it closes on high current, making the two “U” windings
only for starting. It must be considerably less efficient
than running it on three phase. I know HP is derated
for single phase.
 
Save
Reply Quote Like Like
21 - 40 of 57 Posts
About this Discussion
56 Replies
14 Participants
Last post:
Sberry
WeldingWeb - Welding Community for pros and enthusiasts
posts
1.8M
members
82K
Since
2003
Community Forum for Welding Professionals and Enthusiasts To Interact and Learn - Free
Full Forum Listing
Explore Our Forums
Welding Projects & Pictures General Welding Questions MIG, TIG, Stick, And Oxy/Fuel Welding Machines - Tools and Cutting Methods Lincoln