length of 4 core cable 95mm from substation LV VFD panel to
Motor at field approximately 150 meter. Motor stop and power
has been isolated from LV MCC ( Substation )to disconnect
Motor for services. After Motor completed service propose to
reinstall and reconnect Motor Cable, found earth cable
sparkling during touching at metal / motor body.
Inspect by clamp meter found earth cable have current flow
AC 1-2amps and all earth cable at MCC LV also have current
flow as same value. why it is happen?
Answer Posted / mrinmoyboruah
Cable insulation together with cable conductors form
capacitance. On nergising a cable this capacitance gets
charged and cable charging current flows even if no load is
connected at cable end. Similarly when cable is disconnected
from power source it retains the original charging energy
until it finds a conducting path to earth for discharge.
Hence before touching a disconnected cable all its
conductors including metal sheath and armours should be
connected to a earth path so that the stored energy in the
cable gets discharged.
| Is This Answer Correct ? | 0 Yes | 2 No |
Post New Answer View All Answers
how we select ac fuse rating of an power inverter???
EXPLAIN USE OF ROCKING ARRANGEMENT IN ELECTRIC HEATING?
what is the formula for efficiency of francis turbine and generator for hydropower? what is best way to select francis turbine and generator?
please give me all the Alarm .Trip ,Safety Relays & Conditions of Diesel-generators mail me on ashokbabunhce@gmail.com
What is the meaning of loop in transformer
Fantio of tranformer
what is inter connected dc generator?
how many joints are allowed in underground HT cable of 1 KM
Match the following a)(X'+Y') b)X'Y' C)XY 1)NAND 2)NOR 3)Carry
WHAT IS DIFFERENCE BETWEEN CAPACITOR AND CAPACITANCE?
for 5KW resistive load can anyone please suggest me whether to go for UPS/Inverter or Generator depending upon cost calulations
what is magnetizing and demagnetizing current in generator and motor?
List the time domain specifications.
What information we need to prepare relay coordination chart
I have a small system with two motors that are running on 380 vac, 60 hz. These motors are expensive and I usally get them from Brazil. I am adding another motor to the system, but I want to purchase a 480 vac, 60 hz motor to use. It will be on a VFD that is rated fro 380 thru 480. Is this posible and will I have to use a larger motor and derate it?