Name a form of testing typically performed on electrical systems during commissioning.

Insulation resistance testing is essential during the commissioning phase of electrical systems because it assesses the quality and integrity of the insulation surrounding electrical conductors. This testing ensures that insulation is sufficient to prevent unintended current leakage, which can pose safety hazards, lead to equipment failures, or cause disruptions in service.

During insulation resistance testing, a megohmmeter is used to apply a high voltage to the insulation and measure its resistance. A high resistance value indicates that the insulation is intact and functioning properly, while a low resistance value may signal potential failures or degradation of the insulation material.

Performing this test is crucial for verifying that the electrical system can operate safely and effectively before it goes into service. Proper insulation resistance helps to avoid electrical faults, which can lead to significant downtime and costly repairs later on. This testing is a key component in ensuring the reliability and safety of any newly commissioned electrical installation.