An AC High Voltage Tester is a device used to check the insulation strength and safety of electrical equipment, cables, and components. It applies a high alternating voltage to the equipment under test and checks if the insulation can withstand the stress without breakdown or leakage. This process ensures safety, reliability, and compliance with industry standards. AC high voltage testers are widely used in power plants, electrical industries, laboratories, and manufacturing units to identify weak insulation, defects, or faults before the equipment is put into service.