INSULATION RESISTANCE TEST

 IR TEST @ 250 V DC

These electrical tests will find issues within the windings of a motor using resistance. It provides a test of the quality of insulation resistance (IR), which will start degrading as soon as the motor is in use due to temperature effects. Motors in harsh environments (high humidity, dirt, particles) may need routine checks of the IR to avoid any failure, as small shorts from moisture or dust can lead to major issues if undetected. IR testing can highlight dead cables, shorts, loose connections, open circuits, or any other blatant winding issue that can alter the winding resistance. These resistance measurements must be compensated for temperature after each test; this way, the resistance measurements are standardized when compared over time. This test can also be used to balance 3 phase motors, as the phase-to-phase resistance of each winding can be compared to see how they differ from one another. Note that these tests are typically done on off-line motors – that is, motors that have been removed from their power source, for safety and ease of inspection.

A protection opposition analyzer (known as a "megger") is regularly used to rapidly evaluate the engine's protection obstruction. This gadget utilizes a DC voltage (100-5000+ V) to recognize protection breakdown within an engine. Similar to a multimeter, a megger has two leads where one interface with the ground and the other to explicit engine leads. If the megger shows low obstruction esteem when wired to the engine, it implies that the way to the ground has been compromised and the engine should be fixed. Then again, if the megger shows high obstruction esteem, it implies that it recognizes no significant spillage in the wire's coherence. It is a basic test that is non-intrusive and gives fundamental data about current spillage, winding shortcomings, and extreme pollution, yet because of its low voltage, a few flaws will go undetected.

CONNECTION DIAGRAM:

EQUIPMENT USED:

MEGGER MIT 520/2, 5 KV INSULATION TESTER.

RESULT:

Temp: 42°C

Phase	IR 15sec (M-OHM)
Phase to earth (After VARNISHING)	15