Interested to Buy Any Domain ? << Click Here >> for more details...
Do you know how to measure the earth resistance? if so
explain it
- 42 Answers
- 180958 Views
- ABB, BEL, BridgeStone, College School Exams Tests, Dalkia, Dalmia Group, DEC, Electrical, Genpact, HEC, IOCL, JLL, L&T, MSEB, Saraca, Sical, Telecommunications, University Exams, I also Faced
- E-Mail Answers
Answer Posted / yogesh
the current being supplied from the AC power lines.
Alternatively, a bridge may be
used for measurement. Most often, the ground resistance is
measured with selfcontained
instruments such as the Megger ground resistance Tester.
The resistivity of earth may vary over extremely wide
limits, depending on the
composition of the soil and the moisture content.
Representative values are:
General average 100 ohm-meters
Swampy ground 10-100 ohm-meters
Sea water 0.01-1 ohm-meters
Dry earth 1000 ohm-meters
Pure slate 107 ohm-meters
Sandstone 108ohm-meters
Fig. 2 Equivalent radius A of groups of ground rods of
radius "a"
I current
V voltmeter
Ground under test Reference ground Auxiliary ground
Fig. 3 Fundamental method of ground resistance measurement
TYPE 3235 Earth TESTER
Adequate earthing systems for telecommunications,
electronic and electrical
equipment, power lines and lightning arresters of steel
towers and high buildings are
of extreme importance. Good earthing systems safeguard
personnel and equipment
during fault conditions. They are also frequently necessary
in minimising electrical
noise and for normal, reliable operation of electrical and
electronic equipment. The
resistance of any earthing system should be periodically
checked to ensure that it is
within limits.
The Type 3235 Earth Tester can be used to check almost any
earthing system. It
incorporates a test for earth voltage. AC voltage up to 30V
may be measured. High
S S S
S S S S
A=SQRT(a S ) S
A= cube root of(aS2) A= fourth root of(sqrt(2)aS2)
S
| Is This Answer Correct ? | 15 Yes | 13 No |
Post New Answer View All Answers
i am an maintenance engineer. one distribution board have 5 feeder. recently its ELR trips frequently, but it take some times after trip( 10min,20min..)but 3 feeder no load. two feeder only loaded. i checked one feeder IR value all values are above 50Mohm.but B phase to Earth is only 9Mohm.any problem about low value
What kind of preventive maintenance are there for transformer?
What is meant by a stray loss of a induction motor??? What is the equation to find it
How should i design a 1ph & 3 ph transformer. Kindly let meknow all steps and formulaes related to design from scratch.
please send me the L&T Emb. sys. placement papers and entire details of pattren
As an electrical engineer what are the responsibilities which i can hold in TCS?
for 5KW resistive load can anyone please suggest me whether to go for UPS/Inverter or Generator depending upon cost calulations
Define piezo-electric effect?
How much no load current of synchronous motor
What are the Full Forms of TVM, MTL, CVT ?
what are the usual topology of transformers at different substations in the power system and why that particular topology is choosen. what are the limitaions of that topology?
Why colled 440V to 3-phase supply.
I have experienced electrical maintenance HT ,but I completed be ECE ....can I apply c license or not ???? Pls help me friend s...
which model T or pie model is prefarable in power syatem
No load tap changing transformer working
