Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Rejected Takeoff; Flight Crew Returned To Gate; General Maintenance Action; General Flight Cancelled / Delayed
Aircraft
Around 100 knots on takeoff roll received multiple caution msgs; and; my PFD and MFD went dark for a few seconds. Captain decided to reject takeoff. It turns out the right Gen went out but also took a T.R with it. Bus ties were not working as they should. Ran DDG off the runway and taxied back to the gate. Mx had problems resetting the bus ties. Mx finally got everything everything straightened out and we left for ZZZ without further incident.
Slightly above 80 kts we got some screens flickering; then load shedding; multiple EICAS messages; which included R Gen Off. Since it appeared worse than a Gen Off indication I elected to abort the takeoff at about 100 kts. We informed tower and cleared the runway at G taxiway. Stopped the aircraft upon clearing the runway to run checklists; evaluate the situation; and see how hot the brakes will get. Upon further inspection we also had a Transformer Rectifier Status message. I elected to run the R Gen Off QRH but that was unsuccessful especially since the status message. I told the First Officer to run his after takeoff flow. We then contacted our companies Dispatch via Satcom. Told them the situation and that we would do a block turn back to give the plane back to maintenance. Me and the First Officer monitored the brake temperatures as we seen a high of 8 on the btms. The brakes were already cooling off really good and we didn't anticipate any problems so we elected to slowly taxi back into the blocks. When the First Officer did a walk around he didn't notice any defects to the tires; or brakes; etc. Maintenance had to do an engine run up to disconnect the Electric drive as there appeared no way to get that generator back online. When they did that they got multiple load shedding and the Lower Eicas went blank. The Apu generator was operating so none of that should have been happening and it appeared to be a bus tie issue not closing properly. They did a couple engine run ups and eventually got the bus ties to work correctly; the Gen Drive to disconnect normally; and got the Transformer Rectifier Eicas to clear. We later operated the flight with 1 engine generator and the Apu on the whole flight per the DDG. No other issues noted.
Flight Crew reported a rejected take off caused by electrical system failures.