- It is an Electrical Safety Device to Protect Electronic Equipments in TCC from Over Voltage
- If DCL voltage exceeds 3000 V, Soft Crow Bar action is taken by LCC
- If DCL Voltage exceeds 3400 V, Hard Crow Bar action is taken by LCC
Soft Crow Bar
- LCC itself Rectifies this Trouble, by Controlling Excitation
- Surge voltage is diverted through resistor
- Most of the time it is reset when TH is moved to Idle
- If any message is displayed, can try with TCC recycling
Hard Crow Bar
- Whenever hard crow bar acts, GFC will open and very low resistance will be connected between positive & Negative
- LCC will Cut off full Power. TE Meter will indicate Zero; heavy oscillation from Truck will be Experienced
- DID will give a message with Alarm
- “No Load”
- “Communication Failure “
- “Hard Crow Bar Fired – TCC 1 / 2”
- Recycle both TCCs after securing C/stand
Medha Loco
Additionally
Brake chopper is provided – acts at 2800 V
If hard
crow bar acts, Message is displayed to Shut down & Re Crank Engine