At the time of Electrical Installation various Testing equipments used by Electricians according to their need. It can be single function or multifunction equipments.
New Electrical Installation should be tested before its commissioning and charging. Testing equipments should meet certain international accepted standards.
Here we will understand the operation of Various Electrical testing equipments:
1) Themography Equipment
Electrical equipments generates heat under operating conditions. At the time of Overload and loose connections heat generation is more.
As show in above picture, Different colors shows difference in temperature. So, Ultimately, we will come to know the heating produce by the equipments or at the connections of different parts.
2) Phase Sequence tester
Phase sequence tester is used to check correct phase rotation of 3-phase supplies. Rotating Lamps or indicators shows phase rotation of 3-ph system at particular measuring point.
3) Low Resistance Tester
This is very useful Testing Instruments used to measure earth resistance or continuity of conductor or any electrical path.
This instrument has voltage below 24 volts and current less than 200 mA. Resistance measuring range from 0.2Ω to 2Ω and with resolution of 0.01Ω.
In old days analogue instruments were used, nowadays digital instruments with self ranging functions are used in Electrical installations.
4) Insulation Resistance meter
Most widely used testing equipment in electrical installations to measure Insulation Resistance of any Electrical Equipments. It shows insulation Resistance between Live phase and earth.
At the time of measurement it should takes 1 mAmp. It is also called high resistance tester because it measures Resistance in Mega-ohms.
5) Earth Fault loop Impedance meter
This instrument is to measure impedance of the whole Earth fault current loop.
Impedance of the whole Fault current loop should be Low enough for operation of over current protective devices to operate withing standard time disconnection time.
At the time of testing low current flow should be there to avoid unwanted tripling of the devices.
6) Earth electrode resistance tester
Measurement of Earth electrode resistance is required particularly sensitive equipment like generators and transformers at time of installation.
During this test equipotential lead should be disconnect from each earth electrode. This tester is always comes with 3 or 4 probes. Measured value of resistance is in terms of ohms.
7) Prospective short circuit current test
Prospective short circuit current test used to measure amount of current that would flow at the time of short circuit of two conductor of live phases. The value of the current is in terms of Kilo Ampere.
Most of the instruments measures current between phase and neutral than doubling of than value gives phase to phase current at the time of electrical installation measurement.
8) Polarity test
At the time of Electrical installation, by engineers this test can be done by Voltmeter or test lamp to ensure that all the switches and circuit breakers are connected in Live conductor.
9) Residual current device tester
This test is done by electrical engineers to verify the effectiveness of residual current devices(RCDs) at the time of operation with correct effectiveness.