y-delta or acroos the line connection

[jojhanv]

hello guys,

can anyone give me an idea when i should use a y-delta connection or an across the line connection for an electric motor circuit? just want to know how much Hp should I start connecting with a y-delta. The line is 3PH, 50Hz.

thanks guys!

 

[silva.foxx]

Depends on load type and available supply.

Can't find a definite rating but 'popularity' appears to be around 5 HP or even 5 kW depending where you read it. ?:|

 

[Evans Electric]

Its to do with the starting load, so a motor with drive belts to turn a flywheel ,say, would need to start in Star .

 

[Bacon]

As Mr Evans has stated it will depened on the load in which the motor is to be used,

Starting current on start up may be quite high then as the speed has built up it would switch over to delta usually via a timer on big applications .

 

[Sidewinder]

The general rule of thumb as around what Silvaa has given.

However, it is application specific, though, there is little to be gained with small motors, and for larger motors the shock loads of DOL need to be limited.

 

[Chr!s]

A lot will depend on the supply and frequency of switching