Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
It is possible to make a 3 phase electric motor run on a single phase supply, but it requires a complex device made from inductors and capacitors. I saw one once, a long time ago but I do not have a circuit for it.
there are ready made inverters to power three phase motors from single phase. some of them can double voltage as well to power motors operating on 208, 230 or 240V. Problem is that your motor is big so forget the single phase VFDs.
Maximum power you can draw from 120VAC 15A outlet is less than a half of your motor size. You may be able to find 25A outplet but it's still small.
You could try to use both 180deg phases (2x120=240V) and capacitor to create phase shift (needed for start). This will again mean reduced power of the motor and starting difficulties depending on capacitor selection (may have to start it without load).
Note that you can use this motor without capacitor too. When you flick the switch it will not rotate, it will need external spin to get it started. Of course this can be dangerous sincethe motor will accelerate.
Be very carefull with capacitors, make sure they are rated for proper voltage or they may explode.
Maximum power you can draw from 120VAC 15A outlet is less than a half of your motor size. You may be able to find 25A outplet but it's still small.
You could try to use both 180deg phases (2x120=240V) and capacitor to create phase shift (needed for start).
You're assuming he has the strange USA mains system?, I would imagine it's more likely he has the more normal single phase off of a three phase street supply?.
In the UK, the maximum you can take from one socket is 13A, and it's 230V (supposedly!) - which is about 3KW maximum. For larger requirements (which are ONLY industrial), you need to pay to have three phase installed.
I don't see why not run three phase motor on a three phase power.
In continental Europe it is available practically everywhere
(residential too, and I've been in Germany, Austria, Slovenia, Croatia and Holland).
There are numerous ways to power a 3 phase motor from a single phase source. One would involve a motor-generator - single phase motor driving 3 phase generator. Another was already described and might actually be less expensive than you think. Many of the common variable frequency drives can take a single phase input and provide a 3 phase output - I am told by people in the business that there is nothing special about this approach - it's off the shelf stuff.
Yet another approach is to use another 3 phase motor in an arrangement that will convert the single phase to 3 phase. I think it might have been called a rotary convertor. The convertor motor can be smaller than the motor that is powered but it must be rotating initially in order for the conversion to work. Once started it will spin by itself. Apparently this was quite common but finds little use today. I helped my brother build one (for 10 hp motor) - it works but one can't expect the 3 phase motor to deliver full power because of significant phase imbalances. The money and aggravation of this approach far exceeds the cost of a modern variable frequency drive.
I keep using Variable Frequency Drive even though you've not stated that you want to vary the rpm of the motor. VFDs are common and more easily found with this term.
As Nigel points out, all of what you are doing has to be done knowing the limits of your single phase system.
and to be more precize its a motor for an woodcutter/shafer?
one with a roller wich needs to spin fast, the wood will then be mooved by 2 people and the machine will take off the wood easyly..
the problem is where i'm building the house from wood there isn't Light!
sow we hired an agregate? an dynamo powerd by an engine and that dynamo/alternator only delivers one phase power...
Now i have brought an one phase engine wich delivers 2,2Kw..
and the alternator delivers 5500Watts... i tryed the engine on a socket
and when you plugit in it looks likes its blocked, then comes another "spark" and it starts running.......
when i use it with my 5500watt alternator it locksup the 13BHP engine..
and the hole machine stalks..except when i help the engine spinning and then plugin fast the Socket then it keeps spinning and the 13Bhp engine doesn't change much in sound...
sow it looks like it doesn't has the reaction power due to the mechanical accelerator/compensator?? is this right??
Hi, I made a rotary converter from an old Heemaf Hengelo 5 Hp 3Ø 220/380 Volts motor.
I start it up from 1Ø 16 Amps MCB at 230 Volts 50 Hz on R and S phases.
On S ans T phases I have 125 µF 400 Volts capacitors which aid in getting the motor to start, when the motor is up to speed, takes about 2 seconds the capcitors are switched off by means of a relay. The 3Ø motor runs very well on single phase, it has a heavy pulley on it.
From the motor terminals I have 3Ø 230 Volts available from which I can start up to two different 3Ø motors 1.8 and 2 kW with no problems.
Now i have brought an one phase engine wich delivers 2,2Kw..
and the alternator delivers 5500Watts... i tryed the engine on a socket
and when you plugit in it looks likes its blocked, then comes another "spark" and it starts running.......
when i use it with my 5500watt alternator it locksup the 13BHP engine..
and the hole machine stalks..except when i help the engine spinning and then plugin fast the Socket then it keeps spinning and the 13Bhp engine doesn't change much in sound...
sow it looks like it doesn't has the reaction power due to the mechanical accelerator/compensator?? is this right??
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
