Flight Crew Air Transport Pilot (ATP)
Other / Unknown
Aircraft Equipment Problem Critical
General Maintenance Action; General Declared Emergency
Aircraft
We took off with one generator on MEL. (I believe it was 24-20-01) Number 1 generator inoperative.  About 60 miles east of destination we got a low oil pressure Indicated Drive Director (IDG) 2 Electronic Centralized Aircraft Monitor (ECAM) which calls for IDG disconnect and subsequent 1 generator operation. I handed aircraft and radios to first officer after he checked to see if it was an immediate action item or ECAM exception. I did ECAM and disconnected IDG.  We were now down to single generator Auxiliary Power Unit (APU) and I had the First Officer (FO) declare an emergency. The QRH had a follow-up but didn't add anything new.We thought that although the weather wasn't great at destination; there was really no better alternative and we were already set up to go in there. I contacted the Dispatcher and he agreed that was best.We requested runway 28R which was longer and quicker and it was approved. I also requested the equipment just in case.  We were given priority handling and landed uneventfully. The flight attendants were told to prepare for a normal landing. The equipment followed us to the gate uneventfully.We picked this aircraft up just as maintenance was MELing it for the inoperative IDG. The write-up in the logbook was IDG low oil pressure and I thought it very strange that here was the identical failure on the next flight for the other IDG. I just wonder if maybe the IDG's had not be serviced properly. Other than that I am not sure how to prevent this except maybe make generators unable to be on MEL.
A320 Captain reports being dispatched with an inoperative generator (IDG low oil) with the APU generator operating. During descent the remaining engine driven generator Indicated Drive Director (IDG) indicates low oil and is disconnected. A normal landing ensues at destination.