3 phase motor compensation capacitors

I have a 5.5kW 400v 3 phase AC motor. Can anyone help with the
calculation to work out the size of the compensation capacitors.
TVMIA.
Reply to
colinstone
Loading thread data ...
The more info you give on the motor, the better the caps can be sized. Based on efficiency of 93% and a pf of about 88%, 3 kVAR caps (1 kVAR per phase) may be okay. There are a number of things you can screw up by using capacitors, I hope you know what you are doing.
Reply to
operator jay
Nope - hence the question!. Motor will be used to power a bow thruster, so must be reversing. Efficiency is likly to be around 93% - not yet bought. Friend has a 5.5kw motor DOL on a 10kw genset - so aiming to do the same.
Reply to
colinstone
On 4/9/07 4:48 PM, in article snipped-for-privacy@o5g2000hsb.googlegroups.com, " snipped-for-privacy@hotmail.com" wrote:
Why do you need to compensate at all? Why not just take the hit on power factor?
Bill -- Fermez le Bush--about two years to go.
Reply to
Salmon Egg
What will the power source for this motor be? A VFD for speed control perhaps? That will change the answer significantly.
Reply to
Paul Hovnanian P.E.
I think it's time to hire an electrician, you have managed to end up with all the concerns of and between gensets, capacitors, starters, motors and motor starting, in this one little installation.
Reply to
operator jay
Bow thruster motor 3ph 400V 5.5kW will be driven by 11.3 kW 3000rpm Fischer Panda genset. Motor will be 4 pole and will be either on or off - I do not need to change motor speed. Options seems to be:
DOL starting - friend has a 2 pole 5.5kw motor DOL on a 10kw 1500 rpm genset. DOL with motor compenstaion to bring PF back to 1, or as near as possible. Soft starter. VFD drive.
TVMIA
Reply to
colinstone

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.