Calculation of capacitor value for conversion from star to delta

[The Ghost]

Hi does anyone have a notion of how to calculate the capacitance value for the above?

 

[Pete999]

No sorry

 

[buzzlightyear]

Star Delta Wiring Calculator - Education - http://www.reuk.co.uk/Star-Delta-Wiring-Calculator.htm

 

[The Ghost]

Nice thanks for that @buzzlightyear, never thought of google, too used to asking the wife.

 

[buzzlightyear]

to used to asking the wife.

what ,then the kettles on !

 

[The Ghost]

Not quite it though looking at it. It gives the values of volts and amps etc. but not the capacitance for the "third" phase calculation unless I am missing something.

 

[static zap]

No sorry

I'm with Pete ,
How many wires do you have access to ?
(calculator looked like its for alternators!)

 

[davesparks]

Sorry if this is a daft question, but where does a capacitor come in to converting from star to delta?

 

[Lucien Nunes]

Do you mean for running a 3-phase motor from a single-phase supply?

 

[The Ghost]

So I take the 3 cross linked (two links) on the star configuration, and move the links directly down to the terminals on the other side and place L on one terminal and N on the other terminal I need a connection the third coil usually a capacitor taken from on of the other terminals depending on rotation required. So as to provide power to the third coil.

 

[The Ghost]

running a 3-phase motor from a single-phase

Exactly, converting from three phase to single phase.

 

[buzzlightyear]

could you not get a gerbil on a spinning wheel for that.

 

[westward10]

Or single to three

 

[The Ghost]

How many wires do you have access to

Not sure yet, but think I may have to place a capacitor in a three phase motor converting it to single phase. I presume I will see six wires three incoming and three linked as set up for three phase star configuration. Then I got to thinking what value capacitor for the (say)mid point connection. I suppose I can ask the motor manufacturer. They supply a wiring diagram but not the capacitor. I am not even sure yet what I will be dealing with as I have not looked at the connection but what else can it be after all. Assuming it's a bog standard wiring/motor 3 coils etc.

 

[The Ghost]

gerbil on a spinning wheel

Yes please, sounds nice and straightforward.

 

[Lucien Nunes]

There is no one ideal value as the third leg current depends on the mechanical load, and if this is highly variable a compromise value is needed. The motor will always be running under abnormal conditions and its performance and power will be reduced.What is the application?

 

[The Ghost]

It's a 2Hp 9a 2Kw motor for irrigation on a farm. It may be it is single phase so nice and simple I am not sure if they send them all out as three phase or what at the moment awaiting more information.

 

[The Ghost]

So this pump will pump clean water to the field and has a Domino UP controller which is really just a fancy switch(ing) system to control and alarm running dry, or managing other switches such as float switch or pressure switch (Danfoss KPI35) for the expansion tank. I realise the float switch may be redundant. The Domino checks dry running through setting the Cos/Phi level at the motor.

 

[Andy-1960]

A single phase to three phase inverter may be a better option

 

[The Ghost]

single phase to three phase inverter

Mhmm that seems a lot less of a head ache.