Changes taking place while taking DB

•   BKT/s braking magnet valve energizes and BKT/s move to Braking position

•   Engine speed raises to 4^TH notch RPM / 5^th notch – Roof mounted / Siemens – based on DB     Current

•   Except P2, P22, S21 & S31 all other EPPCs picks up

•   TM Armature connected to grids & all TM Fields connected in series across Rectifier Block

•   BKBL starts working for cooling grid resistor

•   BKIV / D1 pilot valve energizes to avoid conjunction brake application

•   LAM indicates the current flow to the grids from TM armature

Circumstances when DB should not be used

•    If BKIV / D1 pilot valve defective / not energising

•    If engine speed not raising to 4^th notch RPM

•    If BKBL is not working

•    Power ground during DB (GR1 tripping)

•    LAM needle overshoots the DB current limit

•    LAM needle fluctuates  or not indicating during DB

•    If TM is isolated

•    GFC packed condition