Do you know how to measure the earth resistance? if so
explain it
Answer Posted / felix shapilo
Ohmmeter measurements are normally made with just a two-
point measurement method.
However, when measuring very low values of ohms, in the
milli- or micro-ohm range, the two-point method is
not satisfactory because test lead resistance becomes a
significant factor.
A similar problem occurs when making ground mat resistance
tests, because long lead lengths of up to 1000
feet, are used. Here also, the lead resistance, due to long
lead length, will affect the measurement results.
The four-point resistance measurement method eliminates
lead resistance. Instruments based on the four-point
measurement work on the following principle:
· Two current leads, C1 and C2, comprise a two-wire
current source that circulates current through the
resistance
under test.
· Two potential leads, P1 and P2, provide a two-wire
voltage measurement circuit that measures the voltage
drop across the resistance under test.
· The instrument computes the value of resistance from the
measured values of current and voltage
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
dg started in plc mode and load taken later one battery terminal connection will be disconnected by loose connection what will happen for dg and shall we connect battery terminals while dg in load time?
The Howland current source produces a A Unidirectional floating load current B Bidirectional single-ended load current C Unidirectional single-ended load current D Bidirectional floating load current
At full load wat is the motor p.f And at no load will is the motor p.f?
Why computer humming sound occurred in ht transmission line?
differnce between single acting and double acting solenoid valves
How does a battary stores charge in it? please explain in simple manner and in detail.thanks
Why open circuit test of transformers is conducted at rated voltage??Why not any other voltage??
Can Anyone Answer anyone of these ? Q1) why direct SOLUTION of Load Flow Studies in Not Possile ? Q2)Why majority of Buses in power system are load buses Q3)Why one of the buses in Power system is taken as reference bus (slack or swing) Bus ? Q4)Bus Admittance Matrix is a sparce (means it contains some zero elements ) matrix , give reason
What shall be the secondary output voltage if the primary winding of a 220/6V, 50 Hz transformer is energized by an 110V, 60 Hz supply?
how we explain parallel paths armature winding?
while starting a liquid starter ,is there any volage drop on water/soda on tank.can we touch the tank on starting?
How to design the no. of ceiling fans required in 5mtr X 10 mtr X 3 Mtr hight room?
How isolater function when installed inelectrical 440V wiring
Type of motor stater detail and working detail
why we used ZNO in Lightning arrester.