EN Testing

There are many safety standards in place ensuring that a manufacturer’s electrical product leaves the production line safe, efficient and fit for purpose. Each standard applies to various types of electrical equipment, ranging from laboratory equipment to common domestic appliances - additionally providing the manufacturer guidance on which electrical tests to conduct in order to deem their product compliant.

So which electrical tests must a product undergo in order to satisfy the guidelines within the respective EN standard? Regardless of the product type, a manufacturer can expect to carry out electrical strength (flash) tests, insulation resistance tests, earth bond tests, earth leakage and load tests.

The method in which the manufacturer carries out these tests will depend upon the respective EN standard. The safety of the test environment will also need consideration in order to comply with EN 50191 – Safety in electrical testing: Products on production lines. Safety barriers, beacons, alarms and dedicated test areas are all measures that can aid maintaining a safe and efficient test environment.

Below is a brief overview of relevant electrical compliance tests for each EN standard. This document is not for use as reference when testing. The full EN standards are available to purchase as printed or digital PDF copies from the BSI shop, found by conducting a quick Google search for the relevant standard.

Electrical Equipment Compliance Standards

BS EN 61010

EN 61010 is the internationally harmonised safety standard for laboratory, process control, test and measurement equipment. The scope of the standard covers the following types of equipment:

  • Electrical test and measurement equipment
  • Electrical laboratory equipment
  • Electrical industrial process-control equipment

A) Electrical Strength (dielectric breakdown or flash testing)

The test voltage used is a function of clearance distances, working voltage and pollution degree. This voltage for basic insulation appliances is 1350V. Appliances of double insulation be tested at a voltage of 2200v. Either test result must show no indication of breakdown.

B) Insulation Resistance Test

Conducted at 500VDC, results must be no less than 1 Megohm.

C) Earth Bond Test

Conducted at a voltage no greater than 12V AC/DC, the earth bond test current must be no less than 1.5x of the current capacity of a hazardous circuit at the point where the failure of the basic insulation would make the earth point live. Results must indicate no less than 0.1 Ohm.

D) Earth Leakage Current

Class I hand held equipment must not allow more than 0.75mA of earth leakage current. Other class I equipment is permitted no more than 3.5mA of earth leakage current, whereas class II equipment is permitted no more than 0.25mA of earth leakage current.


BS EN 60950

EN 60950 applies to mains-powered or battery-powered IT equipment, including electrical business equipment and associated equipment, with a rated voltage not exceeding 600V. Example equipment that must comply with EN60950 may include computers, displays, telecommunications equipment, network switchgear, projectors etc.

A) Electrical Strength (dielectric breakdown or flash testing)

An AC test voltage of either 1500V or 3000V is ramped up from 0V and held for 60 seconds. For testing DC circuits (internally derived): RMS test voltage = (DC component of circuit. Voltage peak value of ripple voltage) + v2. Either test result must show no indication of breakdown.

B) Insulation Resistance Test

Conducted at 500VDC, results must be no less than 1 Megohm.

C) Earth Bond Test
Conducted at a voltage less than 12V AC/DC. The test current must be no less than 1.5x of the current capacity of a hazardous circuit at the point where the failure of the basic insulation would make the earth point live. Results must indicate no less than 0.1 Ohm.

D) Earth Leakage Current

Class I hand held equipment must not allow more than 0.75mA of earth leakage current. Other class I equipment is permitted no more than 3.5mA of earth leakage current, whereas class II equipment is permitted no more than 0.25mA of earth leakage current.


BS EN 60204

EN 60204 is a harmonised standard to the machinery directive, and the use of it in designing your machine will give you a presumption of conformity to the corresponding EHSR‟ of the machinery directive 2006/42/EC.

EN 60204 applies to the application of electrical, electronic and programmable electronic equipment and systems to machines not portable by hand while working, including a group of machines working together in a co-ordinated manner.

A) Electrical Strength (dielectric breakdown or flash testing)

LV equipment is tested at 2000V for 5 minutes, PELV equipment is tested at 500V for 5 minutes. Either test result must show no indication of breakdown. Higher test voltages may be required for type testing or power tools.

B) Insulation Resistance Test

Conducted at 500VDC for 5 minutes, results must be no less than 1 Megohm.

C) Earth Bond Test

Conducted at a voltage no greater than 12V AC/DC and at a current of 200mA into a short circuit. Results – pass indicated when no more than 50V can be developed by the circuit voltage across the measured resistance. Earth bonding at test voltage is derived from a PELV source at a test current of at least 10 amps and at a frequency 50 Hz. The test voltage is applied for a period of at least 10 seconds and is conducted between the PE terminal and the various points that comprise the protective bonding circuit. The results are given as the maximum measured voltage drop for a protective conductor of specific case between 1 and greater than 6mm2 in accordance with table 7 of the standard.

D) Earth Leakage Current

Class I hand held equipment must not allow more than 0.75mA of earth leakage current. Other class I equipment is permitted no more than 3.5mA of earth leakage current, whereas class II equipment is permitted no more than 0.25mA of earth leakage current.


BS EN 60335

BS EN 60335 provides general requirements ensuring the safety of electrical household appliances, providing their rated voltage is not more than 250V for single phase and 480V for other appliances. The standard also looks at the general requirements and conditions to test the domestic safety of electric household appliances.

A) Electrical Strength (dielectric breakdown or flash testing)

Half of the full voltage (50Hz AC test voltage of up to 2500V or a DC test voltage of up to 3750V) is applied and gradually ramped up to the full test voltage and held for 60 seconds. Higher test voltages may be required for type testing or power tools.

B) Insulation Resistance Test

Conducted at 500VDC and held for 1 minute, results should be no less than 2 Megohm or 7 Megohm.

C) Earth Bond Test

Conducted at a voltage no greater than 6VAC. The test current must be 25A, results must not exceed 0.1 Ohm.

D) Earth Leakage Current

Class I hand held equipment must not allow more than 0.75mA of earth leakage current. Other class I equipment is permitted no more than 3.5mA of earth leakage current, whereas class II equipment is permitted no more than 0.25mA of earth leakage current.

Test Equipment

Manufactured under the Seaward brand, Clare instruments are used on production lines and in test laboratories all over the World. Their instruments allow manufacturers to verify the safety and performance of millions of electrical products every day, complying with BSI, BEAB, ASTA, BABT, VDE, UL, CSA, The Lighting Association, HAE, EN60598, EN60335, EN60950, EN61010, EN60745 standards and many more.

The Clare product range caters for the hire/rental and manufacturing industries, offering solutions that can integrate into physical production and ISO systems, as well as being able to output electronic signals in order to control equipment such as conveyor belts and other electronically operated equipment.

Below is a comparison table which overviews the range and displays the tests that each product will conduct. If you need any further assistance regarding the products, please do not hesitate to contact us on 01132 48 99 66.

EN Testing Table