3-phase

[Big_Spark]

Stod, try the link I supplied to a pdf file from Vent-Axia.

Then you will see the OVERALL picture not the individual as sold picture.

FFS I have it on paper as a hard copy in front of me as supplied with the fan.


I have worked on motors almost all my 21 year career, so I do know what I am talking about..although sometime the way I explain it may not be as clear as desireable!

Incidently, to earn extra money as an apprentice, I worked for Clarke International, helping to repair and design motors, both single phase and 3 phase.

 

[Stod]

Stod, try the link I supplied to a pdf file from Vent-Axia.

That's the pdf I was talking about. It's the one with the six connection diagrams and associated fan model numbers as I described in my last post.

 

[Big_Spark]

Stod, did you not read my post.

Have a look at this link carefully click me

The motors are the same for three phase or single phase, the difference is in how they are connected, and that the controller details are different.

Incidently, Vent Axia confirmed this on the phone..I think they know what their talking about.

 

[supersparks]

i have to say this but, i would think FWL knows about 3 phase motors!!
if he dosnt then i am very worrid!

 

[kendor]

looks like FWL will not take no for an answer! The I am right and you are wrong statement says it all!!! Ok FWL you continue to believe you are right on this one and everyone else will think differently.

 

[Big_Spark]

looks like FWL will not take no for an answer! The I am right and you are wrong statement says it all!!! Ok FWL you continue to believe you are right on this one and everyone else will think differently.

Kendor, you are exactly the same, I have backed up what I said by stating you should PHONE the motor manufacturers As far as I was concerned they KNOW better that you, I or the gatepost what they are doing, and as they say exactly what I have been saying, of course I know I am right in this matter.

The fact that the Primary and Auxillery windings will not be 90 degrees out of phase in a red herring, they will be 120 degree out, and this still generates a rotating magnetic field..don't believe me...do the maths and work it out.

As far as I am concerned this discussion is dead. I won't even bother to explain how to create a single phase motor with no capacitor, but make it self starting. (Yes I know it won't be a cheap and cheerful affair, but it is possible)

 

[kendor]

The fact that the Primary and Auxillery windings will not be 90 degrees out of phase in a red herring, they will be 120 degree out, and this still generates a rotating magnetic field..don't believe me...do the maths and work it out.

Again you are misquoting me I didn't say they would be 90 degrees out of phase i said that they wouldn't be at 90 degrees PHYSICALLY
agreed the windings in a three phase stator would be 120 degrees out in relation to each other but this is perfect for the the three phase supply being connected to it.
Going back to the beginning of the argument, I know you could get a three phase motor to run but the argument is running properly.
again i have to repeat a LARGE 3 phase motor would not run properly if adapted to run on single phase the way you are suggesting.

 

[raittser]

1 - if you are thinking of aquiring a 3ph supply you will probably find that your electricity supplier won't do it in a domestic situation or if industrial will cost you an arm and a leg
2 - get in an expert, people will get hurt

 

[BR]

3 pages of a nonsense argument on 3-phase motors. I'm afraid I cannot fault FWL in what he is saying although it was a little misleading at times.

I have been fitting large (I’m talking industrial, over 100Kw) 3-phase motors for the last 25 years,
I have never come across a 3-phase motor, which cannot be run from a single-phase supply (although it may be totally inappropriate to do so). Somebody said they will not run properly, if the setup is designed and installed by somebody who knows what they are doing the motor will run reasonably well Point accepted, there it is never really going to be need to do this, it is in answer to a question on motor theory.
There is nothing special about the vent-axia motors; these are a perfect example to explain how such motors are connected.

The I am right and you are wrong statement says it all!!!

Yeah, he's an arrogant b*astard, we all know that but as I said above, I personally cannot fault him.

Arguing a point is all very well, but some people just don't know when to stop. Somebody like me (and Jim I imagine) have spent many years studying such systems, and more importantly have gained great experience from fitting and troubleshooting such devices all our lives. I know I being a bit cocky here but it has to be said.

 

[Big_Spark]

Thank you Brian, nice to hear from someone who knows what their talking about..nice to know that I am am not wrong in thinking I don't always explain things properly when writing it down too

 

[Big_Spark]

Here are some quoted from manufacturers

All Electromotor 3 phase motors between 0.04kW and 25kW are supplied with capacitors so they may be used on single phase supplies should this be necessary. The capacitor is not connected, on installation the links across the winding terminals need to be altered according to the supplied instructions, and the supply wired through the capacitor. Larger 3 phase motors can be used on single phase, please contact the Sales Engineers to discuss specialist requirements.

Bolem 3 phase motors are manufactured with the end user in mind, all can be easily converted to single phase use by the addition of the optional capacitor kit available for all our motors from 0.5kW to 22.7kW. Other sizes are available to special order; please contact Bolem Sales Representatives to discuss your requirements.

ABB 3 phase motors represent an investment in your infra-structure, not only are they ultra-reliable. Altering the link configuration in the terminal block allows these motors to be quickly converted from 3-phase star to 3-phase delta or even single phase should this be required.

Features: economical performance, environmentally friendly according to DIN EN 60034 (IEC 72), mounting dimensions. Degree of protection IP 55, higher degrees of protection up to IP 65 available on request, insulation class F with thermal reserve, insulation class H optionally available, terminal boxes up to size 315 available optionally on top, left-hand, right-hand multiple modifications.

Posted so that people are aware that Brian and I have actual experience of this for those that were not aware it was possible.

 

[kendor]

there you go it mentions capacitor kits!! now go back to read what i said originally.
I was saying that the motor would not work on single phase without this modification that's all i said and at last you produce documentation to agree with what i said, so where was i wrong and you were right then????
I mention capacitors merely as an example there are other methods also and as i state before you can get any motor to run on any system if you stick the right technology in between. I have connected 110 volt series DC motors that draw 120 amps(output side) off of a three phase supply(415v) through Eurotherm Drive Invertors for example, these cleverly use a six thyristor bridge arrangement to drive the motor through field and armature connections the only problem i had was having to devise a method of reversal as it was as a series motor and the drive merely powered the A+ and A- I achieved this by using a Stud diode arrangement in the form of a bridge across the motors field windings and when the drive was told to reverse its poles the bridge effectively forced the current to flow in the same direction through the field winding but change in the armature thus reversing the motor this allowed forward and reverse drive of a Camera Crane.

 

[Stod]

I accept that it is possible to configure a three phase induction motor to operate on a single phase supply, but that was not the point. FWL said that most three phase motors are designed to run on single phase too. I was not aware of this so asked for a link so that I could read up on the subject. I never said that I thought FWL had got it wrong.

Three times FWL has given a link to Vent-Axia’s connection diagrams, saying that they show how to connect a three phase motor to operate on single phase. I’ve read them and I can find nothing to suggest that a three phase fan can be connected to operate on single phase. So I’ve taken up FWL’s suggestion and emailed Vent-Axia’s technical section.

Here’s the question I asked and the response from Graham Pearson of Vent-Axia technical support:

Subject: Turboprop fan TP 450-34
Can this fan be connected to work on a single phase supply?
If it can, how and is there a performance penalty in doing so?

And the response:

Thank you for your enquiry into Vent-Axia ventilation.

I'm afraid you cannot wire the Turbo Prop TP450-34 with a single phase supply; this is a 3 phase fan only.
Sorry I cannot be of more help,

Kind regards

Graham Pearson
V/Axia Tech Support

 

[kendor]

I accept that it is possible to configure a three phase induction motor to operate on a single phase supply, but that was not the point. FWL said that most three phase motors are designed to run on single phase too. I was not aware of this so asked for a link so that I could read up on the subject. I never said that I thought FWL had got it wrong.

Three times FWL has given a link to Vent-Axia’s connection diagrams, saying that they show how to connect a three phase motor to operate on single phase. I’ve read them and I can find nothing to suggest that a three phase fan can be connected to operate on single phase. So I’ve taken up FWL’s suggestion and emailed Vent-Axia’s technical section.

Here’s the question I asked and the response from Graham Pearson of Vent-Axia technical support:

Subject: Turboprop fan TP 450-34
Can this fan be connected to work on a single phase supply?
If it can, how and is there a performance penalty in doing so?

And the response:

Thank you for your enquiry into Vent-Axia ventilation.

I'm afraid you cannot wire the Turbo Prop TP450-34 with a single phase supply; this is a 3 phase fan only.
Sorry I cannot be of more help,

Kind regards

Graham Pearson
V/Axia Tech Support

You could if you used a single phase to three phase convertor.
But this would be a (rather expensive)case of additions again.

 

[Big_Spark]

Maybe if you two (Stod and Kendor) stopped trying to prove me wrong, backtrack and read what I wrote, then you will see that your latest comments are misleading.

Stod, if it cannot be done, pray tell how did I do it at a golf club over easter? The Fan is working fine and within spec.