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. Under the Dutch Working Conditions Act, the employer must make sure PPE is in good condition. A periodic test and a test report are how you demonstrate that.

IEC 60903 divides electrical insulating gloves into six classes based on the maximum use 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. A dielectric test can be done at the owner’s request. Classes 1 to 4 always get an air test, a visual inspection under pressure and the dielectric water-bath test.

IEC 60903 permits both methods, each with its own proof voltages. 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 the ASTM D120 proof test for class 4 (70 kV DC) in one setup.
• For a DC test, IEC 60903 gives no leakage current limit. The glove must hold the proof voltage without breakdown.

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

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 check whether air escapes. Inspect it visually while it is under pressure.

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

For an AC test, the maximum leakage current depends on class and glove length (IEC 60903 Table 4). For a periodic re-test the limit is lower than the table value. For a DC test, Table 4 gives no leakage current limit: what counts is that the glove holds without breakdown. Always record the measured value in the test report.

6. Certification

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

IEC 60903 (Annex E) recommends not using class 1 to 4 gloves if the last test was more than 6 months ago, even if they were in storage. Of all PPE in this series, this is the shortest interval. A glove that has sat in the cupboard for more than 6 months must be re-tested before use.

The 70 kV DC insulating glove tester from Megabras delivers up to 70 kV DC and is set per glove class. That covers all IEC classes (00 to 4) and the ASTM D120 proof test for class 4 in one setup. Leakage current measurement is built in. For safety it has an emergency stop, a lock button on the high-voltage unit for connecting the cables, and automatic spark detection.

Combine the glove tester with a hot-stick test stand and you can also test insulating sticks in-house.

With your own tester you schedule the tests yourself, ship nothing and keep the test data in-house. On the other side are the purchase, the calibration of the tester and training your staff. Prefer to outsource? IONIO Labs tests your gloves to IEC 60903, with a test report for every pair.

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 limit in IEC 60903. For a periodic re-test that limit is lower than the table value. The result goes into 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 suitable up to a maximum use voltage of 500 V, 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. Re-test of class 1 to 4: no later than 6 months after the last test, 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. If you prefer not to do it yourself, IONIO Labs can carry out the testing for you.

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.

IONIO tests and inspects electrical insulating gloves to NEN-EN-IEC 60903 (air test, visual inspection under pressure and dielectric DC test, class 1–4). See the service electrical insulating glove testing or all inspections and lab tests at IONIO Labs. Do you also need voltage detectors tested?

Questions? Get in touch via the contact page or schedule a consultation.