AS NZS IEC 60947.7.3:2015 pdf download.Low-voltage switchgear and controlgear Part 7.3: Ancillary equipment- Safety requirements for fuse terminal blocks.
8 Tests
8.1 Kinds of test Subclause 8.1 of IEC 60947-7-1 applies.
8.2 General Subclause 8.2 of IEC 60947-7-1 applies with the following modification. The tests shall be carried out in the order as given in Annex C.
8.3 Verification of mechanical characteristics
8.3.1 General The verification of mechanical characteristics includes the following tests:
— attachment of the fuse terminal block on its support (8.3.2); — mechanical strength of the clamping units of a fuse terminal block (8.3.3); — compatibility between fuse terminal blocks and fuse-link (8.3.4); — mechanical strength of the connection between the terminal block base and the fuse- carrier (8.3.5).
8.3.2 Attachment of the fuse terminal block on its support Subclause 8.3.2 of IEC 60947-7-1 applies.
8.3.3 Mechanical properties of clamping units of a fuse terminal block
8.3.3.1 Testing of mechanical strength of the clamping units Subclauses 8.2.4.1 and 8.2.4.2 of IEC 60947-1 apply with the following addition. The test shall be made on two clamping units at the centre terminal blocks out of five fuse terminal blocks mounted as in normal use on the appropriate support according to the manufacturer’s instructions. Rigid conductors of the rated cross-section shall be connected and disconnected five times.
8.3.3.2 Testing for damage to and accidental loosening of conductors of a fuse terminal block (flexion test) Subclause 8.3.3.2 of IEC 60947-7-1 applies.
8.3.3.3 Pull-out test Subclause 8.3.3.3 of IEC 60947-7-1 applies.
8.3.3.4 Verification of rated cross-section and rated connecting capacity Subclause 8.3.3.4 of IEC 60947-7-1 applies.
8.3.4 Compatibility between fuse terminal blocks and the fuse-link The maximum gauge no. 1 or no. 4, in accordance with Table A.1, shall be inserted and
withdrawn 10 times from the fuse-carrier. Following each insertion of the gauge, the fuse-carrier shall be fitted to the terminal block base as in normal operation. In the case of fuse terminal blocks with screw-type fuse-carrier, the fuse-carriers shall be fitted with a torque of two-thirds of the value specified in Table 1.No visible damage or loosening of parts shall be observed. The minimum gauge no. 2 or no. 5, according to Table A.1, shall be prevented from falling out of the fuse-carrier in the most unfavourable position. The minimum gauge no. 2 or no. 5 shall then be inserted into the fuse terminal block and the contact resistance be measured according to 8.4.4 (see Figure 1). The mean value of the contact resistance shall not exceed 10 mft The value of an individual measurement shall not exceed 15 m1.
8.3.5 Mechanical strength of the connection between the terminal block base and the fuse-carrier
8.3.5.1 Torque test on screw-type fuse-carriers The fuse-carrier equipped with the maximum gauge no. I or no. 4, in accordance with Table A.1, shall be screwed in five times into the terminal block base by applying the respective torque specified in Table I. The fuse-carrier shall be securely kept in the terminal block base during and after the test, and shall show no changes impairing its normal use.
8.3.5.2 Pull-out test on screw-type and bayonet-type fuse-carriers The fuse-carrier equipped with the maximum gauge no. I or no. 4, according to Table A.1, shall be inserted in the terminal block base. Screw-type fuse-carriers shall be tightened with a torque of two-thirds of the value specified in Table I. The fuse-carrier shall then be subjected to an axial pulling force as specified in Table I for 1 mm. The fuse-carrier shall be securely kept in the terminal block base during and after the test, and shall show no changes impairing its normal use.
8.3.5.3 Actuating forces on plug-on type or hinged-type fuse-carriers The fuse-carrier, together with the maximum gauge no. 1 or no. 4 according to Table A.1, shall be inserted in and withdrawn from or slewed out of the terminal block base. The actuating forces shall be measured with appropriate measuring means. This test shall be conducted 10 times. The value of each individual measurement shall be within the limit values as stated by the manufacturer.
The fuse-carrier shall be securely kept in the terminal block base during and after the test, and shall show no change impairing its normal use.AS NZS IEC 60947.7.3 pdf download.