G III/ G1159 (DC version) Question for the Guru's Please

[b19]

G III/G1159 (DC version), Question for the Guru's Please

DC EMERG FDR

Okay I got it ties Batt Tie to ESS DC BUS , but besides APU please give me some of most likely causes for light to come on, etc., etc., both in flight and on ground, and any other thoughts, comments, experience, thanks.

 

[PilotKitch]

If I remember correctly the light comes on when the T/R is energized. We had the light remain on during flight and maint concluded it was a relay that was not opening when you turn off the t/r switch after engine start.