INSULATION TESTER IR4056

Our Most Popular Model Offering Reading Stability in Medium-speed Digital Format

Hioki insulation testers or megohmmeters feature all-in-one designs including built-in rugged cases and test lead storage compartments. The IR4056 is a 5-range, 50V to 1000V digital insulation resistance tester with efficient functions and features to help shorten work time associated with field insulation testing.

CAT III 600 V

Product Video

Key Features

  • 5-range testing voltage of 50 V/100 MΩ to 1000 V/4000 MΩ
  • Stable & medium-speed digital readings, 0.8 second response time of PASS/ FAIL decisions
  • Drop proof onto concrete from 1m (3.28 feet)
  • Bright LED, luminous LCD, test lead with bright LED lamp to illuminate near hand (Also available in the IR4056-21)
  • Continuity check via 200 mA testing
  • Built in AC/DC voltage meter, useful for testing solar power generation systems and electric vehicles

Model No. (Order Code)

IR4056-20 Economic model
IR4056-21 Economic model, Not CE marked

How to Use Digital Insulation Resistance Meters - Basic Course

This video explains how to use a digital insulation resistance tester to measure a distribution panel.
(With Japanese model IR4052. The world-wide model name is IR4057.)

Comparator function provides PASS/ FAIL decisions at a glance

Compare measured values to pre-set reference values to generate a pass or fail judgment with the Comparator function.
(also pair with insulation resistance measurement and low-resistance measurement)

The insulation testers give you pass/ fail results using a beeping sound, LCD light, and indication right on the test lead with remote control switch*, letting you check for insulation integrity without needing to look at the instrument. (*Standard with the IR4056-21)

The image is IR4057

Robust, damage-resistant design

These instruments feature a robust design that can withstand being dropped onto concrete from a height of 1 m.
Difficult to damage, this insulation tester is ideal for use in the field.

White LED lighting that’s easy to read in dim locations in the field

The scale is lit by a white LED, ensuring that insulation resistance values are easy to read, even when using the instrument in a dim location.

The image is IR4057

Measurement switch designed for outstanding ease of use

The instrument’s measurement switch can be operated with just the thumb.
Press for a single measurement or lift up for continuous measurement of insulation resistance.

200 mA grounding line continuity check function

The Insulation testers can perform EV and HEV continuity checks as well as resistance measurement of safety conductors in building electrical equipment as defined by IEC 60364.

Basic specifications

Accuracy guaranteed: 1 year, Accuracy guarantee period after adjustment made by Hioki: 1 year
Rated output voltage 50 V DC 125 V DC 250 V DC 500 V DC 1000 V DC
Effective maximum indicated value 100 MΩ 250 MΩ 500 MΩ 2000 MΩ 4000 MΩ
Accuracy
1st effective measuring range MΩ
±2 % rdg. ±2 dgt.
0.200 - 10.00
±2 % rdg. ±2 dgt.
0.200 - 25.0
±2 % rdg. ±2 dgt.
0.200 - 50.0
±2 % rdg. ±2 dgt.
0.200 - 500
±2 % rdg. ±2 dgt.
0.200 - 1000
Lower limit resistance 0.05 MΩ 0.125 MΩ 0.25 MΩ 0.5 MΩ 1 MΩ
Overload protection 600 V AC (10s) 660 V AC (10s)
DC voltage range 4.2 V (0.001 V resolution) to 600 V (1 V resolution), 4 ranges,
Accuracy: ±1.3 % rdg. ±4 dgt., Input resistance: 100 kΩ or higher
AC voltage range 420 V (0.1 V resolution) / 600 V (1 V resolution), 2 ranges, 50/60 Hz,
Accuracy: ±2.3% rdg. ±8 dgt., Input resistance: 100 kΩ or higher, Average rectifier
Low resistance range For checking the continuity of ground wiring, 10 Ω (0.01 Ω resolution) to 1000 Ω (1 Ω resolution), 3 ranges, Basic accuracy: ±3 % rdg. ±2 dgt., testing current 200 mA or more (at 6 Ω or less)
Display Semi-transmissive FSTN LCD with back lighting, bar-graph indicator
Response time Approx. 0.8 second for PASS/FAIL decision (based on in-house testing)
Other functions Live circuit indicator, Automatic electric discharge, Automatic DC/AC detection, Comparator, Drop proof, Auto power save
Power supply LR6 (AA) alkaline batteries ×4, Continuous use: 20 hours (Comparator off, backlight off, 500 V range, no load)
Number of measurements: 1000 times (at 5 s ON, 25 s OFF cycle, insulation measurement of lower limit resistance value to maintain nominal output voltage)
Dimensions and mass 159 mm (6.26 in) W × 177 mm (6.97 in) H× 53 mm (2.09 in) D, 600 g (21.2 oz) (including batteries, excluding test leads)
Accessories [IR4056-20] Test lead L9787 ×1, Neck strap ×1, Instruction manual ×1, LR6 (AA) alkaline batteries ×4
[IR4056-21] Test lead set with remote switch L9788-11 ×1, Neck strap ×1, Instruction manual ×1, LR6 (AA) alkaline batteries ×4

L9787 options (2)

Exclusively for the L9787 *The L9787 is bundled (IR4056-20)

L9788 options (4)

Exclusively for the L9788-10/ L9788-11 *The L9788-11 is bundled (IR4056-21)

Shared Option (1)