Huacheng Cable ‖ New standard interpretation series 1: GB/T 9330 new and old standards comparison

The National Standards Committee issued GB/T 9330-2020 and GB/T 12706.1～4-2020 in the form of Announcement No. 4 on March 31, 2020, and will be implemented on October 1, 2020. These two standards are closely related to wire and cable companies, customers and testing agencies. So, what everyone is most concerned about is, where are the main changes of the old and new standards of GB/T9330 reflected?

The biggest change is that the new standard simplified the 2008 editions of GB/T 9330.1, GB/T 9330.2 and GB/T 9330.3 into one standard, facilitating the implementation of the industry. The following are other major changes:

1. Added copper/plastic composite tape (foil) shielding, code-named P4.

2. Modify "Conductor of fixed laying cable" to "Conductor of hard structure cable" and "Conductor of mobile laying cable" to "Conductor of flexible structure cable".

3. Increase the shrinkage test and water absorption test of cross-linked polyethylene insulation

4. The requirements for the thickness of the thinnest part of the metal (composite) belt metal layer, the requirements for the coverage rate of the metal (composite) belt shielding and the diameter of the wire braided shielding monofilament

5. The evaluation index for the thickness of the squeezed and wrapped inner lining and the test method for the average thickness of the wrapped inner lining are added

The thickness of the thinnest part of the extruded inner lining should not be less than 80% of the nominal thickness (the calculation result should be rounded to 2 decimal places, that is, accurate to 0.01mm); the average thickness of the wrapped inner lining should not be less than the nominal thickness 80% of thickness (calculation result should be rounded to 2 decimal places, that is, accurate to 0.01mm). The average thickness of the inner lining layer is equal to the sum of the measured thickness of each layer of tape, and the specific measurement method is given.

6. The assessment requirements for the thickness of the armored steel tape and the diameter of the armored steel wire and the test method for the size of the armor layer have been added.

7. Added sheath spark test requirements

The sheaths of metal shielded cables and metal armored cables shall be subject to the power frequency spark test inspection according to GB/T 3048.10-2007. GB/T 3048.10-2007 is suitable for testing the tightness of the anti-corrosion sheath extruded on the metal sheath or metal armor layer.

8. The elongation at break of PVC/D insulation is changed from 150% to 180%; the elongation at break of ST5 sheath before and after aging is changed from 150% to 200%.

9. Removed the ST3 sheath

Table 7 in GB/T 9330.1-2008 "Plastic Insulated Control Cable Part 1: General Provisions":

10. Increased the performance requirements of the polyethylene sheath and the water absorption test of the halogen-free polyolefin sheath

11. Added regulations for test and measurement of core count

It is stipulated in GB/T 9330 "Plastic Insulated Control Cable" (Draft for Approval) "8.1.1 General Requirements": Conductor structure size inspection and insulation thickness measurement. During sampling test, inspection and measurement should be no less than 10% of the core It should be no less than 3 cores (2 cores should be checked and measured for 2-core cables); 3 cores should be checked and measured during type testing (2 cores should be checked and measured for 2-core cables).

12. The halogen-free performance requirements of cable non-metallic materials (see Table 15 of this edition) and fluorine content test requirements have been added

It is stipulated in Table 15 of GB/T 9330 "Plastic Insulated Control Cable":

The halogen-free performance requirements and test methods of non-metallic materials for halogen-free low-smoke flame-retardant cables are shown in Table 15.

13. Inspection requirements have been added

See standard table 19 for details

14. The calculation method of the upper limit of the cable outer diameter has been added

1) The size calculation of "cable insulation core with mica tape refractory layer" has been added

2) Improved the "cable formation factor", which is derived from Appendix A.2 of GB/T 12706.1-2008

3) Added regulations on spacers

4) The calculation method of "Maximum Cable Outer Diameter" is added

15. Other modifications

1) Deleted Table 5-Table 12 in "6.8 Dimensions" in GB/T 9330.2-2008 and Table 6-Table 11 in "6.8 Dimensions" in GB/T 9330.3-2008.

2) Related test items are added in GB/T 9330 "Plastic Insulated Control Cable".