Hioki IR4056-20 Digital Insulation Tester 1000V

Hioki IR4056-20 / IR4056-21 Insulation Tester

The Hioki IR4056 series is the standard insulation tester for industrial electrical maintenance in India. With five selectable test voltages from 50V to 1000V and measurement range up to 4000 MΩ, it covers the full spectrum of insulation testing requirements from low-voltage control circuits to 415V three-phase motors and distribution cables.

The IR4056-20 is supplied with the standard L9787 test lead. For hands-free remote-switch operation, see the IR4056-21.

Key Features

• 5 test voltage ranges: 50V, 125V, 250V, 500V, 1000V
• Insulation resistance measurement up to 4000 MΩ
• DC voltage measurement up to 600V — identifies live circuits before testing
• Comparator function with PASS/FAIL indication — set your limit and get a clear result
• Auto power save
• CAT III 600V safety rating
• IP40 rated dustproof
• 1-drop proof from 1 metre

Included Accessories

TEST LEAD L9787, neck strap, LR6 alkaline battery ×4, instruction manual.

Applications

Routine insulation testing of motors, transformers, cables, switchgear and distribution panels in industrial plants, commercial buildings and infrastructure. The 500V range is the most commonly used in India for standard 415V equipment, while the 1000V range handles HV motors and generators.

Minimum Acceptable Insulation Resistance (500V test)

Good condition: above 100 MΩ | Caution: 10–100 MΩ | Do not energise: below 10 MΩ