Electrical requirements for machinery
Mandatory Electrical Tests for Machine Certification
A question we are asked many times concerns the mandatory electrical tests for machine certification when the harmonized standard EN 60204-1 is to be used for the Declaration of Conformity. In this article we give an answer by defining the minimum requirements and some essential aspects to be taken into account.
The Machinery Directive deals with the topic of electrical safety in requirement 1.5.1 of Annex I (this will also be the case for the New Machinery Regulation), this requirement is very important because, in addition to defining the minimum electrical safety requirements, it is the reference to the Low Voltage Directive (2014/35/EU), which is included in the Machinery Directive.
While on the surface very simple, this requirement can be exploded into so many issues concerning one of the most important aspects of our products, the safety of the operator against electrical hazards that in most cases are present in our machines.
The technical product standard EN 60204-1:2018 is a type-b standard that gives presumption of conformity to the Machinery Directive and in particular requirement 1.5.1,
If you comply with EN 60204-1:2018 you are automatically compliant with the Machinery Directive and the Low Voltage Directive.
Therefore, it becomes very important to consider the proper application of the standard, which gives us precise guidance on what tests should be performed on electrical equipment (and more) in order to ensure safe use and maintenance by the operator.
The mandatory tests according to EN 60204-1:2018
Chapter 18 includes a list of tests of which some are mandatory and others are at the manufacturer’s decision.
a – Verification of consistency of electrical documentation;
b – Verification of the continuity of the equipotential circuit;
c – Verification of protection conditions in case of automatic fault protection;
h – Functional testing.
In the following we will see what are the main aspects to consider for each test.
a - Document verification
It is necessary to verify that the electrical installation is exactly the same as what is depicted in the wiring diagrams, described within the technical file and within the product instruction manual (see also technical documentation in Chapter 17 of the standard).
This test is usually performed when the electrical installation of the machine is complete and may result in a review of related documents.
b - Continuity test
It is necessary to verify the continuity of the machine’s protective equipotential circuit. The protective equipotential circuit must be:
1 – Formally compliant: presenting an identifying wiring with yellow-green colors and/or identification of the ground points by the appropriate symbol IEC 60417-5019 (protective earth)
2 – Have proper resistance: the resistance of the equipotential circuit must be tested between the main grounding point (PE terminal) and all grounding points of the machine (defined in circuit diagram).
The test should be conducted using a tester with current in the range 0.2A – 10A . The resistance measured at each point must be less than or equal to the theoretical resistance calculated considering the electrotechnical characteristics of the circuit.Â
Important to note that this test is not only strictly concerned with the electrical equipment but also with normally inactive, reachable parts that may become live in the event of a fault.
c - Automatic interruption verification
In the case where fault protection is achieved by automatic power interruption, the requirements of §18.2 must be met, with different conditions depending on the distribution system present.
The first step is verification by visual examination of the connection between protective conductors and PE terminal, with subsequent continuity test as described in the previous point.
Only if the results up to this point are positive, we proceed to the second part:
verification of the fault loop impedance by calculation or measurement in accordance with A.1.4;
confirmation that the setting and characteristics of the corresponding overcurrent protective device comply with the requirements of Annex A.
d - Functional test
It is necessary to verify that the product, by means of its electrical circuit, performs all the intended functions.
This test can be performed in the final stage of machine production and must be proved by a test report in which all functions of the machine are verified.
Other tests
All other tests that are listed in Chapter 18 of EN 60204-1:2018 are optional, meaning that the manufacturer must assess the need to perform them based on his experience and the risk analysis conducted on the machine.
Conclusion
The electrical tests just described are the mandatory ones for compliance with EN 60204-1:2018, so they are minimum safety requirements for the sale of Machinery within Europe and for all countries that accept this Technical Standard.
In other countries of the world the mandatory electrical tests may be very different and have more stringent requirements (example America, Canada and Turkey). In order not to incur disputes or blocking of customs products it is always necessary to check what the mandatory requirements are for the market where we place our product.
What can we do for you?
WAVES ENGINEERING often performs electrical testing in the European and international area, we can help you in verifying the requirements of your product and accompany you in achieving compliance for Europe and several world markets.
We provide the electrical i testing service by issuing a report certifying that the tests performed comply with EN 60204-1:2018.
WAVES Engineering S.r.l.