We have five CAT 3516 with SR4 generators, 2000KVA,600V,60Hz, They work in parallel , isochronous speed. Regulator for Speed & Load Sharing control is 2301A and Actuator is EG-10P. AVR is VR3 regulator with original CAT droop transformer and 8 ohm droop pot.
In last time we had a lot of problems with KVAr regulation ( very poor regulation ). Very often we have to adjust system.
AVR-s are old over 20 years. Sensing voltage come from original CAT PT transformer ( 600/240v ) and original CAT power transformer 600/240v.It means we have not PMG.
Now we have new five VR6 CAT regulators and we would like to install it in existing generators panels ( old VR3 was installed in generators ).
Excitor stator has double winding F1-F2 , F3-F4 and for Vr3 regulator windings are connected in parallel ( cca 3,5ohma )
Questions
May I leave winding in paralel or I need connect in serial ( for new VR6 )
What capacity (VA,) and secundary voltage of the power transformer has to be?
What is better solution, take old CAT CT transformer or install new one ( 5A )?
And last questions
Our regulation is only in DROOP mode ( reostat 8ohma -paralell with droop transformer ). CT-s are not connected between AVR-s in Cross-current compensation mode.
Would you please explain us when we use Cross-current compensation mode and when only droop mode ? ( our application )
I would like to tell you, on site we have a lot of induction 3phase motors and seven
DC motors each 600 KW ( oil rig equipment )
Replace CAT VR3 Regulator with VR6
Re: REPLACE CAT VR3 REGULATOR WITH VR6
