thanks again Tim, at 76, I still learn, this is not my trade, but I did wire all the small ships I built, even if I had to get a qualified electrician to sign the AC OFF
Hello. I've got a machine coming in that runs on a 3 phase. But my place only takes one phase. I was looking at getting a rotary converter. Is this all I need. The machine takes 4kw and runs on 15amp and is 380-420v. Im getting confused with the vfd and rotary converters. Any help would be appreciated
Below is a link to my setup. Typically you will need a rotary phase converter that is twice the size of your load so you would need a 8KW motor. twcontrols.com/lessons/how-to-make-3-phase-power-from-single-phase-power-using-a-rotary-phase-converter-including-480vac
Sir I need to run a 20 hp motor which is 3 phase. I was recommended to get a variable frequency drive of 30 hp. The electric line here is 11000 volts. The step down transformer used on the line is of 5 hp. My question is there a risk of the transformer overloading if I use a vfd?
It sounds like these systems are "one unique solution" type situations wrt a load and a run capacitor. Meaning for a specific sized motor, and a specific unchanging load, you need a specific sized capacitor to maintain a balanced system. Correct? In your previous video it seems like in the shop you have plugs, that indicate the load can change. Does it somehow remain balanced or is the imbalance negligible?
They can handle quite a bit of load variation and the balancing isn't that necessary. But I use the test control panels and there were requirements on the voltages in some of my customer specifications.
what you suggest for a Solar PV array behind a rotary phase converter , self-consumption with zero feed-in or full feed-in on grid, in your opinion what can be the right injection point? between the phase converter and the grid meter or inside the main low voltage panel ?
I am curious as to how it corrects the 180 degree shifted phases into balanced 120 degrees. Is the motor just generating C phase and A and B are still being used 180 degrees apart as supplied by the service and C phase is just thrown in somewhere? Or is it true balanced 3 phase power 120 degrees apart?
It is 120 degrees apart, the key to understanding it is when you measure 3 phase, you don't measure to neutral, you measure leg to leg. Video explanation in the works.
Great videos! I have passed by many 3 phase machines since i don’t have, nor can easily get 3 phase power out in the country. I wired my shop and have a fair knowledge of how power works. I have a fairly new 7.5 hp 3 phase more from an air compressor that i bought used and found a used 1 phase to run it. I would like to run a welding machine on 3 phase. If i set up a rotating phase converter, will i be able to run more than one thing on it? Or are the run capacitors figured for just one load? It appeared that once i get the 3rd leg rotating motor right, i can have 3 phase for multiple things. I know your busy, so thanks for your time.
The capacitors are more for balancing the three phases voltages, unless you are doing something like CNCs or something sensitive, that part isn't a big deal. If you need to run a 7.5 hp compressor, you need a 15 hp rotary phase converter such as this one. I would call them, they are very helpful with sizing. amzn.to/39BEYC3
@@TimWilborne thanks for the tip. I figured i could use the 7.5hp 3 phase motor to generate a third line to run a welding machine. I’m curious, do welding machines that are 3 phase need any special balancing after i generate the third line? A welder is the main 3 phase item id really like to have since they are much easier to find used than single phase welders. I mean a welding power supply to run big mig guns. They usually are 3 phase.
I already own my own plc but would like to get a 3 phase fan like you have to imitate a motor. Can you provide a link or tell me what brand that is by chance?
Tim the 220 VAC that comes out of the double pole breaker of the load panel is essentially what comes out of the secondary of the utility transformer outside your residence meaning the two phases L1, and L2 are 180 degrees apart. How then in star connected idle motor can one obtain 120 degrees phase difference between L1, L2, L3? it seems to me that's impossible because incoming L1, L2 are always 180 degrees apart. this then creates an imbalance which may throw the start point(where the three coils connect together) unbalanced meaning having a potential different than earth. which apart from safety considerations, may have other implications. I want to use a 10 HP 3 phase idler motor to generate my "ghost" third leg and use the output to power a 3 phase steam jacketed kettle of 4.1 KW (5.5 HP). although the kettle is wired from factory as 3 Phase, the manufacturer says it can be used as a single phase. Do you see using this setup is a wise choice? or there may be some problems? thanks
Hi George. In a future video I'm going to put a scope on converter and talk about that. In your case, it sounds like all of your loads are heaters, is that correct? In that case it should be able to be rewired to single phase and that would be the best course of action.
No that's not correct. You have to remember that the 3 phases are not the 3 wires. The phases are the potentials that are created between those wires. You have 3 phases that are all 120 degrees apart because your two wires from the pole connect to each end of a single winding and only one end of the other two windings. Then as the motor rotates it inductively couples to each of the 3 windings which are each spaced 120 degrees apart. While the phase converter seems to "generate" one leg it really creates 2 phases. The reason why the voltage on the 3rd leg is "wild" and has poorer regulation is because it is passing through the motor windings (inductors) and the other 2 wires don't. This tends to make its current lag behind and that's what the capacitors do is put the voltage and the current more in phase on that leg.
Just wondering if you have a part 3 to this video. Also I am thinking of using this method though not sure if it will work or not. I am getting a 3p 415v motor maybe 2hp, (not sure if star or delta) Can I use this to run of a 230v 1p 15-32A circuit with start and run caps Then use a 3p step up TX to get the power back to run a 2-3hp motor? (Wanting to run a mill, brobo, lathe)
Second thing is that if you want stability, your idler needs to be at least as large as your load motor. Good rule of thumb is to use an idler at 150% or larger than your load motor to avoid significant droop on the flying phase during startup of your load motor. You CAN run a 400-480V motor on a 120-277V supply - but you need to use a transformer to step up the voltage. Remember then that the power stays about the same across a transformer (plus the additional losses of the transformer). So 240V@10Amps = 2.4kW, 2.4kW@415V = ~5.8Amps. You'll need more Amps from a lower voltage supply to run a higher voltage motor through a transformer (by whatever ratio the transformer is). If you don't understand this stuff as explained, then you should probably have an electrician help you - there's a saying "knows enough to be dangerous, but not enough to know they're in danger...". You just have to get this stuff wrong once, and it'll kill you or someone you love - or burn your building down. There aren't "do-overs" from a fatal electrocution, and we're talking about power levels that will kill without warning.
@@TimWilborne thank you ,im sure we need more info to transfer but what would the equipment costs be for two separate three Phase 30 amp circuits be ? I am planning to change the entrance feed from one tennant to three and on the two additional power servaces i would only want single phase .I am splitting up the building to have multiple rental spaces.
@@TimWilborne, at 4:46, you say "...all on our B-C and A-C measurements, which are based off of that artificial ghost leg." So what I'm asking is: If those measurements are based _off_ of that ghost leg, then what are they based ON instead?
Yeah, that's what I was thinking, @@TimWilborne. So then did you mean that those measurements are "based ON that (artificial) 'ghost' leg" instead of "...off..." (meaning on something else)?
@@HelloKittyFanMan.. I think something is lost in translation. Saying something is based ON something or based OFF something would mean the same thing here.
I love your videos, subscribed instantly - but I want to let you I know I nearly lost a good bit of my finger and my palm (11 stiches) building a similar thing on my desk with fans just like that (previous to finding this video). Please get some grates on those things!! They will rip you right open. Learn from my miskates.
Why would they need to be 3-phase though, @@TimWilborne? I thought 3-phase motors were for heavy-duty applications, so you wouldn't have to have such a big motor to do a big job as he would have to have if it were just a single-phase motor. Why just for a smallish fan?
@@HelloKittyFanMan. No 3 phase doesn't necessarily mean big, I have a 3 phase motor that I can put in my pocket. 3 phase is the easiest way to have variable speed.
There is some gray area on what one would consider a contactor and a relay but I'd say most people would consider the items I'm using in this video relays. Here is a video that will help you. www.theautomationstore.com/contactors-and-relays-starting-motors-sending-signals-whats-the-difference/
Why would you ever need a motor that small, running a device that small like those fans, to be 3-phase? Or is the point of the fans that are set up like this just to have the demo without having big industrial motor?
This is quite a frank and an honest presentation. It helped me learn the concept. Nicely done Tim!
Great to hear!
thanks again Tim, at 76, I still learn, this is not my trade, but I did wire all the small ships I built, even if I had to get a qualified electrician to sign the AC OFF
I hope I'm still learning new things at 76.
"Why didn't the motor run, why did it just hum?"
As one of my professors used to say "because it didn't know the words!" :-)
Such a great demonstration. Please explain a little connections ( may be on the board)... Or did u do it? Did i miss it?
Check out this link from Practical Machinist
www.practicalmachinist.com/forum/threads/rotary-phase-converter-designs-and-plans.101231/
Great video. So much easier to understand this way
Glad it was helpful!
Hello. I've got a machine coming in that runs on a 3 phase. But my place only takes one phase. I was looking at getting a rotary converter. Is this all I need. The machine takes 4kw and runs on 15amp and is 380-420v. Im getting confused with the vfd and rotary converters. Any help would be appreciated
Below is a link to my setup. Typically you will need a rotary phase converter that is twice the size of your load so you would need a 8KW motor.
twcontrols.com/lessons/how-to-make-3-phase-power-from-single-phase-power-using-a-rotary-phase-converter-including-480vac
Sir I need to run a 20 hp motor which is 3 phase. I was recommended to get a variable frequency drive of 30 hp. The electric line here is 11000 volts. The step down transformer used on the line is of 5 hp. My question is there a risk of the transformer overloading if I use a vfd?
It sounds like these systems are "one unique solution" type situations wrt a load and a run capacitor. Meaning for a specific sized motor, and a specific unchanging load, you need a specific sized capacitor to maintain a balanced system. Correct? In your previous video it seems like in the shop you have plugs, that indicate the load can change. Does it somehow remain balanced or is the imbalance negligible?
They can handle quite a bit of load variation and the balancing isn't that necessary. But I use the test control panels and there were requirements on the voltages in some of my customer specifications.
what you suggest for a Solar PV array behind a rotary phase converter , self-consumption with zero feed-in or full feed-in on grid, in your opinion what can be the right injection point? between the phase converter and the grid meter or inside the main low voltage panel ?
That sounds like a fun project but it is out of my realm of expertise.
I am curious as to how it corrects the 180 degree shifted phases into balanced 120 degrees. Is the motor just generating C phase and A and B are still being used 180 degrees apart as supplied by the service and C phase is just thrown in somewhere? Or is it true balanced 3 phase power 120 degrees apart?
It is 120 degrees apart, the key to understanding it is when you measure 3 phase, you don't measure to neutral, you measure leg to leg. Video explanation in the works.
@@TimWilborne Ill be awaiting the video, will be interesting
Great videos! I have passed by many 3 phase machines since i don’t have, nor can easily get 3 phase power out in the country. I wired my shop and have a fair knowledge of how power works. I have a fairly new 7.5 hp 3 phase more from an air compressor that i bought used and found a used 1 phase to run it. I would like to run a welding machine on 3 phase. If i set up a rotating phase converter, will i be able to run more than one thing on it? Or are the run capacitors figured for just one load? It appeared that once i get the 3rd leg rotating motor right, i can have 3 phase for multiple things. I know your busy, so thanks for your time.
The capacitors are more for balancing the three phases voltages, unless you are doing something like CNCs or something sensitive, that part isn't a big deal. If you need to run a 7.5 hp compressor, you need a 15 hp rotary phase converter such as this one. I would call them, they are very helpful with sizing.
amzn.to/39BEYC3
@@TimWilborne thanks for the tip. I figured i could use the 7.5hp 3 phase motor to generate a third line to run a welding machine. I’m curious, do welding machines that are 3 phase need any special balancing after i generate the third line? A welder is the main 3 phase item id really like to have since they are much easier to find used than single phase welders. I mean a welding power supply to run big mig guns. They usually are 3 phase.
Thanks for the video, what’s the little monitor name and model? Would like to get one of those. Cheers
Here you go. Just a heads up, the instructions are brutal but if you contact the seller he'll send you a better set. controls.tw/szatq
Noob question. If i have a 2 machines do i need two rotary inverter on each machine?
No, that is one of the advantages of the rotary phase converter over other alternatives. You simply need to add up all of your loads.
I already own my own plc but would like to get a 3 phase fan like you have to imitate a motor. Can you provide a link or tell me what brand that is by chance?
There are a few more on the market. This one is by Oriental Motors
Great Teaching Video!
Thanks!
Tim the 220 VAC that comes out of the double pole breaker of the load panel is essentially what comes out of the secondary of the utility transformer outside your residence meaning the two phases L1, and L2 are 180 degrees apart. How then in star connected idle motor can one obtain 120 degrees phase difference between L1, L2, L3? it seems to me that's impossible because incoming L1, L2 are always 180 degrees apart. this then creates an imbalance which may throw the start point(where the three coils connect together) unbalanced meaning having a potential different than earth. which apart from safety considerations, may have other implications. I want to use a 10 HP 3 phase idler motor to generate my "ghost" third leg and use the output to power a 3 phase steam jacketed kettle of 4.1 KW (5.5 HP). although the kettle is wired from factory as 3 Phase, the manufacturer says it can be used as a single phase. Do you see using this setup is a wise choice? or there may be some problems?
thanks
Hi George. In a future video I'm going to put a scope on converter and talk about that.
In your case, it sounds like all of your loads are heaters, is that correct? In that case it should be able to be rewired to single phase and that would be the best course of action.
No that's not correct. You have to remember that the 3 phases are not the 3 wires. The phases are the potentials that are created between those wires. You have 3 phases that are all 120 degrees apart because your two wires from the pole connect to each end of a single winding and only one end of the other two windings. Then as the motor rotates it inductively couples to each of the 3 windings which are each spaced 120 degrees apart. While the phase converter seems to "generate" one leg it really creates 2 phases. The reason why the voltage on the 3rd leg is "wild" and has poorer regulation is because it is passing through the motor windings (inductors) and the other 2 wires don't. This tends to make its current lag behind and that's what the capacitors do is put the voltage and the current more in phase on that leg.
Just wondering if you have a part 3 to this video.
Also I am thinking of using this method though not sure if it will work or not.
I am getting a 3p 415v motor maybe 2hp, (not sure if star or delta)
Can I use this to run of a 230v 1p 15-32A circuit with start and run caps
Then use a 3p step up TX to get the power back to run a 2-3hp motor?
(Wanting to run a mill, brobo, lathe)
Hi Keagan. The first thing I see is you aren't going to be able to use that 415V motor on your 230V 1 phase power.
Second thing is that if you want stability, your idler needs to be at least as large as your load motor. Good rule of thumb is to use an idler at 150% or larger than your load motor to avoid significant droop on the flying phase during startup of your load motor.
You CAN run a 400-480V motor on a 120-277V supply - but you need to use a transformer to step up the voltage. Remember then that the power stays about the same across a transformer (plus the additional losses of the transformer). So 240V@10Amps = 2.4kW, 2.4kW@415V = ~5.8Amps. You'll need more Amps from a lower voltage supply to run a higher voltage motor through a transformer (by whatever ratio the transformer is).
If you don't understand this stuff as explained, then you should probably have an electrician help you - there's a saying "knows enough to be dangerous, but not enough to know they're in danger...". You just have to get this stuff wrong once, and it'll kill you or someone you love - or burn your building down. There aren't "do-overs" from a fatal electrocution, and we're talking about power levels that will kill without warning.
could i run a 30 amp 3 phase a/c compressor on single phase ?
Yes, very common for a rotary phase converter.
@@TimWilborne thank you ,im sure we need more info to transfer but what would the equipment costs be for two separate three Phase 30 amp circuits be ?
I am planning to change the entrance feed from one tennant to three and on the two additional power servaces i would only want single phase .I am splitting up the building to have multiple rental spaces.
What voltage monitor is that?
Can't recall, it wasn't spectacular.
Where did you find those small 3 phase fan motors at?
Hi Brian, see link below.
www.theautomationstore.com/230vac-3-phase-ac-axial-fan-160mm/
So if it's based off of that "ghost leg," then what's it based ON?
Not following your question
@@TimWilborne, at 4:46, you say "...all on our B-C and A-C measurements, which are based off of that artificial ghost leg." So what I'm asking is: If those measurements are based _off_ of that ghost leg, then what are they based ON instead?
@@HelloKittyFanMan.. The idler motor generates the 3rd leg.
Yeah, that's what I was thinking, @@TimWilborne. So then did you mean that those measurements are "based ON that (artificial) 'ghost' leg" instead of "...off..." (meaning on something else)?
@@HelloKittyFanMan.. I think something is lost in translation. Saying something is based ON something or based OFF something would mean the same thing here.
I love your videos, subscribed instantly - but I want to let you I know I nearly lost a good bit of my finger and my palm (11 stiches) building a similar thing on my desk with fans just like that (previous to finding this video). Please get some grates on those things!! They will rip you right open. Learn from my miskates.
Hi Jon. Thanks for subscribing! All our trainers have fan guards. This one was removed since we needed access to spin it
why dont you just pair 2 motors (2 and 3 phase) on single shaft (or belt driven), start the 2 phase, and use the 3 phase motor as a generator?
You can, I have an older article on that. The starting capacitors are a more common way of doing it today and overall more economical.
@@TimWilborne Got it.
Thank you.
How about a schematic of this setup
It's in the works, I'm just behind on videos :)
Great video! Thanks!
Thanks Benjamin. I hate that I didn't get through the run and start capacitors but I'll get them next time.
I bet you DID have that video even if we have already watched. But why isn't it there now?
Which video?
@@TimWilborne: The one in which you showed how a real rotary phase converter works.
Thanks for your comment love!
th-cam.com/video/k9tR9d3DsqY/w-d-xo.html
It turns out: electric dryers and ranges use 3 phase Electricity
Some industrial ones may be but residential will be 220VAC single phase with a neutral.
I am not understand because my country 440 volt 3 phase supply
440, 460, and 480 are really the same voltage. Regionally the exact number used does change.
I am using 4 3 phase motors easily connect three phase supply in my electrical grid lines
My English not good
In the United States most standard non-industrial establishments have 220V single phase. So we don't have three phase and must make it.
India's electrical system normal different
Why are there small fans that are 3-phase?
I know larger servers use them for cooling, not sure what else.
Why would they need to be 3-phase though, @@TimWilborne? I thought 3-phase motors were for heavy-duty applications, so you wouldn't have to have such a big motor to do a big job as he would have to have if it were just a single-phase motor. Why just for a smallish fan?
@@HelloKittyFanMan. No 3 phase doesn't necessarily mean big, I have a 3 phase motor that I can put in my pocket. 3 phase is the easiest way to have variable speed.
Why are you calling the contactor a relay. Last i checked relays and contactors are twondiffrent things
There is some gray area on what one would consider a contactor and a relay but I'd say most people would consider the items I'm using in this video relays. Here is a video that will help you.
www.theautomationstore.com/contactors-and-relays-starting-motors-sending-signals-whats-the-difference/
💛💚💜
Why would you ever need a motor that small, running a device that small like those fans, to be 3-phase? Or is the point of the fans that are set up like this just to have the demo without having big industrial motor?
It is a trainer for teaching 3 phase and drives
OK, thanks for your reply and comment love,@@TimWilborne