in trains i have seen the terminal which is connected at
the top of the train is positive .where is negative ?
track? i dont think so
- 9 Answers
- 8472 Views
- I also Faced
- E-Mail Answers
Answer Posted / shashank
Dear All,
Not all traction systems work on AC supply. Wherever there
is a DC supply used, the return path is providedby the
earth i.e. the ground. Now comming to the vasics of
electrical engineering, Voltage is a unit for the Potential
diference (PD). PD itself says that there needs to be a
difference in the potential of both the electrodes for the
current to flow. It is not only that if the OHE has +ve
potential the system will work but even if the OHE has -ve
potential then also the system will work as automatically
the earth becomes the +ve eletrode.
But Indian railway uses +ve supply with referance to the
earth, hence we dont ger a shock as already the potential
is zero.
Whereas the AC Supply is concerned i agree to what manesh
has said. with the only addition that the neytral is
grounded i.e. earthed.
Shashank
| Is This Answer Correct ? | 0 Yes | 1 No |
Post New Answer View All Answers
operation of protection relay watchdog contact?
what is meaning of sympathetic tripping with respect to relays and give the values for current carrying capacities for copper and aluminium cables from 16sq mm to 500sq mm
What is difference between start imitation and start interlock for 3 phase motor protection ?
what are the advantages and disadvantages of speed control of 3 phase induction motor by varying frequency explain with drawing
What is the difference in calculating size of AC cables compared to calculating size of DC Cables? Usually DC Cables are larger than AC Cables although they have the same ampacity. Why is it?
what is the difference between ups & inverter
In the formula : Knee point voltage = Burden X alf / class, Please inform what is alf? regards Shashidhar M.R.
write circuit diagram for a motor rotate in forward direction once it started and when pressed the same button it should rotate in anticlockwise.
How to calculate the heat load for a electrical room
My question is whether bellow formula is correct to find bus size for 46kA for 0.5 second & what is RT in bellow formula. formula to calculate the size of busbar to withstand the thermal stresses due to currents with duration of 0.2 sec to 5 sec. Sp = RT( I x I x t) / K Where Sp – is the cross sectional area of bus bar in millimeters. I - is the value of AC fault current. t - is the operating time of disconnecting device in seconds. K – is the factor depending on the material of the conductor, insulation and initial and final temperature. Value of ‘k’ for copper is 143.
state the disadvantages of carbon filament???
critically criticize the application of ring main unit in power system
How to identify the start and end of 3phase 12 lead motor if U1, U2, etc numberings are lost or erased.
Define transfer function?
how to maintain frenquncy with syncronising sub-station for distribution
