Testing electrical insulating gloves per IEC 60903

A breached glove looks fine from the outside. No visible tear, no hole, but aged rubber or a pin-hole that only shows up in the dielectric test. For work above 1 kV that is a direct danger to the worker.

IEC 60903 — published in Europe as EN 60903 — sets out the classes, test voltages, method and testing interval. The Dutch Working Conditions Act obliges the employer to test periodically and to demonstrate this with a test report.

Classes and test voltages

IEC 60903 divides electrical insulating gloves into six classes based on the maximum working voltage. For the periodic test you place the glove in a water bath, apply the proof voltage for one minute and measure the leakage current.

The DC test voltages are listed in IEC 60903 (Table 4).

Class 00 and 0 are tested with an air test and visual inspection. Dielectric testing only on doubt or after an incident. Classes 1 to 4 always require the full water-bath test.

AC or DC — which do you use?

IEC 60903 permits both methods. What determines the choice:

• Some grid operators require AC on the test certificate. Check this in advance with your client.
• A 70 kV DC tester covers all IEC classes and ASTM D120 class 4 withstand in one setup.

Record the chosen method in the test protocol and on the certificate.

Test procedure step by step

1. Visual inspection

Check for tears, cuts, blisters or discolouration. Visible damage means immediate rejection, no test needed.

2. Air test

Inflate the glove and feel whether air escapes through a seam or the material.

3. Water-bath setup

Glove in a water tank as the outer electrode, water inside the glove as the inner electrode. Water level up to the distance below the cuff edge specified in the standard.

4. Ramp up the voltage

Raise the voltage gradually to the proof voltage for your class and hold for 1 minute.

5. Leakage current measurement

The maximum permissible leakage current depends on the glove length and class per IEC 60903 Table 4. Always record the measured value in the test report and check it against the table value for your specific glove type and length.

6. Certification

Test report with date, serial number, class, method, test voltage and measured leakage current.

Test interval: every 6 months

IEC 60903 prescribes a maximum of 6 months, also for gloves in storage. That is the strictest rule in this series: no exception for stored PPE. A glove that has sat in the cupboard for more than 6 months must be re-tested before use.

The DT70KV glove tester from IONIO

The 70 kV DC insulating glove tester is adjustable between 10 and 70 kV. That covers all IEC classes and ASTM D120 class 4 withstand in one setup. Integrated leakage current meter, automatic discharge after the test, and a safety circuit that only releases voltage with the cabinet door closed.

Combine the glove tester with a hot-stick test stand and you have a complete in-house PPE test room.

In-house setup or outsource?

The threshold is roughly 30 to 50 pairs per test round. Above that, an in-house tester pays for itself within 3 to 5 years: no shipping logistics, scheduling in your own hands, test data kept internal. Below that threshold, outsourcing to a test lab is almost always cheaper.

Frequently asked questions

How do you test insulating gloves?

Start with a visual inspection and an air test. Then comes the dielectric test: the glove is filled with water and placed in a water tank, after which the proof voltage for its class is applied for 1 minute — for example 10 kV AC for class 1. The measured leakage current is checked against the maximum value in IEC 60903 and recorded in the test report.

Which classes of insulating gloves are there?

IEC 60903 (EN 60903) defines six classes: 00, 0, 1, 2, 3 and 4. Class 00 is rated up to 500 V working voltage, class 4 up to 36,000 V. Each class has its own test voltage, from 2.5 kV AC for class 00 to 40 kV AC for class 4. See the table above for the full overview.

When must insulating gloves be inspected and tested?

Visual inspection and air test: before every use. Dielectric re-test: at most every 6 months, including gloves kept in storage. A glove that has sat unused for more than 6 months must be re-tested before use.

Can you test insulating gloves yourself?

Yes — provided you test in accordance with IEC 60903 with suitable equipment and record the results in a test report. From roughly 30 to 50 pairs per test round, an in-house test setup is usually more economical than outsourcing to a test lab.

More about testing high-voltage PPE

This article is part of a series on the periodic testing of high-voltage PPE:

• Testing hot sticks — IEC 60832-1 / 60855-1
• Testing voltage detectors — IEC 61243
• Testing phase comparators — IEC 61481-1
• Testing earthing equipment — IEC 61230
• Testing insulating mats — IEC 61111

Or read the complete overview with all standards and intervals.

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Need them tested? IONIO tests and inspects electrical insulating gloves to NEN-EN-IEC 60903 (visual inspection + dielectric DC test, class 1–4). See our service: electrical insulating glove testing.