Power
ground occurs due to an earth fault (leakage of current) in the power circuit.
TANGI in
Medha / GDM in GE / GR1 in Siemens detects power ground
It
Causes
Engine
speed comes to idle
GF
contactor & EPPCs opens
Load
ammeter drops to zero
DB will be
cut off (during DB)
Message in
DID with alarm
GR1
Energized / Tripped Additional indication
GR1 Knob projects out
Pointer moves to red dot
Lamp indication along with alarm
Power
Ground in Medha Mcp (Sensed by TANGI) Ver.2
TANGI value
more than 0.4 Amps (400 milli Amps), Full Power cutoff with Engine returning to
IDLE
Keep TH in
IDLE, Wait for 15 Sec. – Automatic Fault Reset (In 1 Hour – 3 Times Allowed)
4th
Time Lockout will be experienced – Reset through DID
(GRCO1 can
be opened if required to clear block section)
Power
Ground Medha Mcp (Sensed by TANGI) Ver.3
If TANGI
Value reaches 0.4 Amps, Message is displayed
Every 0.1
Amps increase, 20 % Power Reduction
More than
0.9 Amps, Full Power Reduction with Engine speed coming to IDLE
Keep TH in
IDLE, Wait for 15 Sec. – Automatic Fault Reset (In 1 Hour – 3 Times Allowed)
4th
Time Lockout will be experienced – Reset through DID
(GRCO1 can
be opened if required to clear block section)
ACTION TO BE TAKEN after power ground
Resetting
Procedure – First time or after a long time gap
Bring TH to
IDLE, ECS to Idle and reset GR1
If any
abnormality like smoke / fire is noticed, stop, check & attend / isolate.
If not possible to isolate, contact shed
Resume traction
and work further
Check
control compartment, back panel, Generator Room & TMs at next stoppage
Resetting
Procedure – Second time (Immediately)
If GR1
operates immediately on resuming traction, stop the train, check control
compartment, back panel, Generator Room & TMs for any electrical abnormal
signs like:
Excess heat,
burning smell, smoke, fire
If any
abnormality noticed, isolate the equipment if possible.
If not
possible contact shed.
If no
abnormality, resume traction
Resetting
Procedure – Third time
If again
GR1 operates, immediately stop and check control compartment, back panel,
Generator Room & TMs.
If no
abnormality, open GRCO1, Apply loco brakes. Reset GR1
Keep SA9
applied, take 2 or 3 Traction notches and observe for any abnormality in power
circuit
If no
abnormality, clear section with minimum notches and contact shed.
While
working with GRCO1 open, if any smoke, fire or abnormality noticed fail the
loco immediately
If TM is
suspected, isolate TM and work duly ensuring no mechanical defects / banding
failure
If TM 1, 2,
3 isolated still GR1 may act,.
If needed
open GRCO1 and work duly observing the instructions for power ground.
Inform Shed
/ PRC about occurrence of Power Ground & Loco condition.
Note: Do not use DB, If power
ground experienced.
