Basic principles of quality testing for terminal blocks

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Laboratory personnel conducting quality testing for terminal blocks

Basic principles Basic principles of quality tests

To fundamentally ensure the quality of our products, it is especially important to us at Phoenix Contact that our high quality standards are met in all areas of manufacturing. Our laboratories are very important factors in the quality assurance of our products throughout the entire manufacturing process. This is why our laboratories are the focus of our continuous optimizations and have a large number of accreditations and certifications.

On this page, you will find various standards on the subject of the basic principles. For a better and quick overview, the standards and accreditations included in this page are listed below:

CE accreditation laboratory

The Phoenix Contact development laboratories are accredited by independent accreditation bodies to perform environmental and electromechanical tests in accordance with various environmental and product standards. The test reports coming from these laboratories are internationally recognized, for example, by customers, certification authorities, and government agencies.

Standard / in-house method / versions

Title of the standard or in-house method (indicate deviations or modifications from the standard procedure if necessary)

Specialist area
Electrical engineering DIN EN 60947-1 (VDE 0660-100); EN 60947-1+A1+A2; IEC 60947-1+A1+A2 Low-voltage switchgear and controlgear – Part 1: General rules
Electrical engineering DIN EN 60947-7-2 (VDE 0611-1); EN 60947-7-1; IEC 60947-7-1 Low-voltage switchgear and control gear – Part 7-1: Ancillary equipment – Terminal blocks for copper conductors
Electrical engineering DIN EN 60947-7-2 (VDE 0611-3); EN 60947-7-2; IEC 60947-7-2 Low voltage... – Part 7-2: Ancillary equipment – Protective conductor terminal blocks for copper conductors
Electrical engineering DIN EN 60947-7-2 (VDE 0611-3); EN 60947-7-2; IEC 60947-7-2 Low-voltage... – Part 7-3: Ancillary equipment – Safety requirements for fuse terminal blocks

UL accreditation laboratory (1059)

The Phoenix Contact development laboratories are listed as manufacturer laboratories by the UL LLC. This makes them accredited for the performance of recognized UL tests as part of participation in the client-test data program. The in-house test results are thus used for certification processes and are recognized.

CENELEC Certification Agreement (CCA) protocol

The documentation of the test results is the result of tests on test objects of the submitted product. For mutual recognition by the various authorities and organizations on the European level, the documentation must be declared to be in agreement with the determinations of the respective standard by an accredited institute. The basis for the terminal blocks is IEC 60947-7-1/-2/-3. CENELEC adopted a CENELEC Certification Agreement (CCA) on September 11, 1973 which was most recently revised on March 29, 1983 and which is thus valid today. In the agreement, the test results are documented in a standardized protocol (CCA protocol), which in turn can be submitted as a document to obtain numerous approvals and national conformity markings. Phoenix Contact uses the CCA protocol as part of product approvals and certifications.

IECEE (CB scheme)

Manufacturers of electrical engineering products conduct numerous tests before market launch. These tests are run by certified laboratories and documented. Many approvals and releases are based on globally valid standards and tests. The CB scheme (CB = certified body) is an international program that was created by the IECEE. In this program, all participating laboratories and certification organizations are obligated to mutually recognize the results of the tests and examinations all over the world. Therefore, this program provides all participating manufacturers the opportunity to obtain several national certificates and approvals for their products in a simplified process. The documentation occurs in a test report (TRF) that conforms to the CB scheme based on the requested tests with a simple “pass, fail” or individual values. The Phoenix Contact development laboratories are certified accordingly.

Test sequence (IEC 60947-7-1/-2/-3)

The terminal block standard IEC 60947-7-1/-2/-3 describes the tests performed on terminal blocks for copper conductors. The tests are used to ensure the mechanical (§8.3), the electrical (§8.4), and the thermal (§8.5) features. All tests are performed as individual tests on brand new terminal blocks. Only the flexion and pull-out tests are performed in direct connection. The aging test is only performed on screwless terminal points. The standard is structured as follows:

  1. Feed-through terminal blocks
  2. Protective conductor terminal blocks
  3. Fuse terminal blocks

Protective conductor terminal blocks checked three times in succession for short-time withstand current.



8.3.2 Tight fit of the terminal block Mechanical tests Mechanical strength (connection) Mechanical tests Flexion test Mechanical tests Conductor pull-out test Mechanical tests Connection capacity Mechanical tests Clearances Electrical tests Creepage distances Electrical tests
8.4.3 Surge voltage test and power-frequency withstand voltage test Electrical tests
8.4.4 Voltage-drop test Electrical tests
8.4.5 Temperature-rise test Electrical tests
8.4.6 Short-time withstand current Electrical tests
8.4.7 Aging test Electrical tests
8.5 Needle flame test Material tests

Test sequence (UL 1059)

UL 1059 makes a distinction between terminal blocks based on application (use group) and nominal voltage.

• Part I – Up to 600 V
• Part II – 601 V to 1,500 V
• Part III – Spring force connections
• Part IV – Insulation piercing or displacement connections
• Part V – Protective conductor terminal blocks

The test setup for terminal blocks is described in UL 486A-486B. Spring-cage terminal blocks and IDC or piercing contacts must withstand an additional temperature-rise test (30 days) directly followed by a power-frequency withstand voltage test. They are also subject to an extended cyclic current heating test at 150% of the nominal current (aging). Other requirements: Protective conductor terminal blocks must contact the DIN rail without corrosion. They may only be removed using tools. Green-yellow identification is mandatory. In addition, there are specific values for the voltage drop and the short-time withstand current.


11 Temperature-rise test
12 Power-frequency withstand voltage test
13 Connection test, bent eyelet
14 Cable lug pull-out test
15 Mechanical strength (reconnection)
16 Plastic heat deformation test
17 Connection capacity

Test sequence in accordance with UL 486A-486B



7.1 General requirements
7.2 Cyclic current heating
7.3 Static current heating
7.4 Conductor pull-out and flexion test
7.5 Surge voltage test and power-frequency withstand voltage test
7.6 Conductor pull-out test
7.7 Drop test (height 914 mm)
7.8 Dielectric test in combination with the drop test
7.9 Flexion test for moving terminal block parts
7.10 Cold connection (Canada only)
7.11 Moisture absorption
7.12/7.13 Stress-crack corrosion test

Type test report (IEC 60947-7-1/2)

The product development process in the Phoenix Contact Group is completed with laboratory tests and a product release. Approval is given after the tests relevant for the product have been successfully completed. The tests are described based on the product in performance and technical specifications and are recorded in a test plan. Our accredited laboratories are responsible for the testing. In a European context, terminal blocks are checked based on Low Voltage Directive 2014/35/EU and IEC 60947-7-1/-2/-3, for example. In a UL context, they are checked based on UL 1059 and NEC 508. These test results are documented in a type test report in their entire scope. The report itself contains comprehensive information on the laboratory performing the tests, the equipment used for the test, and the test results. Therefore, type test reports are always treated with a certain degree of sensitivity, because the information they contain is considered confidential. Wider-ranging approvals may be requested based on the type test report. The type test report is also considered a legally-binding verification of the product properties. Phoenix Contact uses type test reports for legally safeguarding the product properties and for product approval.

Competence in connection technology – CLIPLINE quality
The Phoenix Contact terminal blocks are subjected to various tests and standards which go above and beyond the usual terminal block standard. Due to the implementation of appropriate design measures and the use of high-grade materials, the terminal blocks significantly exceed the requirements imposed by standards.
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Quality test of a terminal block in the test laboratory