I.Product Uses and Characteristics
Rated Voltage1.8/3kV and below coal mine PVC insulated power cables, is a safety-type cable designed specifically for fixed laying conditions in underground coal mines. Its core value lies in its flame-retardant and durable properties, ensuring that in harsh and high-risk underground environments, it can provide continuous, stable, and safe power supply for various key equipment, making it an indispensable infrastructure for ensuring safe coal mine production.
II. Product Standards
MT818.12--2009
III. Product Modelsand Names
Model No. | Name Designation |
MVV | Coal mine PVC insulated PVC sheathed power cable |
MVV22 | Coal mine PVC insulated steel tape armored PVC sheathed power cable |
Table1
IV.Product Specifications
Model No. | Core Count | Rated Fixed Electric Voltage kV |
0.6/1 | 1.8/3 |
Nominal Designation Cross Section mm2 |
MVV | 3 | 1.5~300 | 10~300 |
MVV22 | 3 | 2.5~300 | 10~300 |
MVV | 3 + 1 | 4~300 | 10~300 |
MVV22 | 3 + 1 | 4~300 | 10~300 |
MVV | 4 | 4~185 | 4~185 |
MVV22 | 4 | 4~185 | 4~185 |
Table2
V. Technical Requirements
5.1 Conductor
The composition, performance, and appearance of the conductor shall comply withthe provisions of 5.1 in MT 818.11-200x.
5.2 Insulation
5.2.1 The insulation shall use PVC/A material, and its performance shall comply with the provisions of Table 14 and Table 16 of MT 818.11.
5.2.2 The thickness of the insulation shall comply with the provisions of 5.2.2 of MT 818.11-200x and Table 3 of this part.
Table 3 Nominal insulation thickness
Nominal conductor Cross Section mm2 | Rated voltage kV | Nominal conductor Cross Section mm2 | Rated voltage kV |
0.6/1 | 1.8/3 | 0.6/1 | 1.8/3 |
Nominal insulation thickness mm | Nominal insulation thickness mm |
1.5 | 0.8 | — | 50 | 1.4 | 2.2 |
2.5 | 0.8 | — | 70 | 1.4 | 2.2 |
4 | 1.0 | — | 95 | 1.6 | 2.2 |
6 | 1.0 | — | 120 | 1.6 | 2.2 |
10 | 1.0 | 2.2 | 150 | 1.8 | 2.2 |
16 | 1.0 | 2.2 | 185 | 2.0 | 2.2 |
25 | 1.2 | 2.2 | 240 | 2.2 | 2.2 |
35 | 1.2 | 2.2 | 300 | 2.4 | 2.4 |
5.2.3 The cross-section of the insulation layer shall be free of visible defects such as bubbles and sand holes to the naked eye.
5.3 Shielding
Cables with a rated voltage U0/U of 1.8/3kV shall have metallic shielding. The metallic shielding shall consist of copper tapes applied separately per phase or collectively wrapped, with a nominal thickness of 0.10mm, and its average thickness shall not be less than 90% of the specified nominal value.
5.4 Cable core and inner covering
The cable core and inner covering shall comply with the provisions of 5.4 of MT 818.11-2009.
5.5 Armor
The cable armor shall comply with the provisions of 5.5 of MT 818.11-200x.
5.6 Non-metallic sheath
The sheath shall be of ST1 type, and its thickness shall comply with the provisions of 5.6 of MT 818.11-200x; the sheath performance shall comply with the provisions of Table 15 and Table 16 of MT 818.11-200x.
5.7 Operating conditions
5.7.1 The maximum rated operating temperature of the cable conductor is 70℃.
5.7.2 During short circuit (with a maximum duration not exceeding 5s), the maximum temperature of the cable conductor shall not exceed 160℃.
5.7.3 The ambient temperature when laying the cable shall not be lower than 0℃, and the minimum bending radius shall be 15 times the cable diameter.
6 Test methods and inspection rules
The cable shall be tested according to the provisions of Table 4 to check whether it meets the corresponding requirements. The inspection rules shall comply with the provisions of Chapter 6 of MT 818.11-200x.
Table 4 Test items
Serial number | Item name | Test requirements | Test type | Test method |
Standard number | Clause number | 0.6/1kV | 1.8/3kV |
1 | Conductor DC resistance | MT 818.11 | 6.2.1 | R | R | GB/T 3048.4 |
2 | AC voltage test | MT 818.11 | 6.2.3 | R | R | GB/T 3048.8 |
3 | Structure and dimension inspection |
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3.1 | Conductor structure | MT 818.11 | 6.3.2.1 | S | S | Visual inspection |
3.2 | Insulation thickness | MT 818.11 | 6.3.2.2 | S | S | GB/T 2951.1 |
3.3 | Armor | MT 818.11 | 6.3.2.3 | S | S | GB/T 2951.1 |
3.4 | Sheath thickness | MT 818.11 | 6.3.2.4 | S | S | GB/T 2951.1 |
4 | Flame retardant performance test |
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4.1 | Single vertical burning test | MT 818.11 | 6.3.5 | S | S | MT 386 |
4.2 | Burning test under load conditions | MT 818.11 | 6.3.5 | S | S | MT 386 |
5 | Structure and dimension inspection |
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5.1 | Insulation thickness | MT 818.11 | 6.4.6.1 | T | T | GB/T 2951.1 |
5.2 | Sheath thickness | MT 818.11 | 6.4.6.2 | T | T | GB/T 2951.1 |
6 | Insulation resistance test |
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6.1 | Test at room temperature | MT 818.11 | 6.4.2.3.2 | T | T | GB/T 3048.5 |
6.2 | Test at maximum rated operating temperature | MT 818.11 | 6.4.2.3.3 | T | T | GB/T 3048.5 |
7 | 4h AC voltage test | MT 818.11 | 6.4.2.4 | T | T | GB/T 3048.8 |
8 | Impulse voltage test | MT 818.11 | 6.4.2.5 | — | T | GB/T 3048.13 |
9 | Conductor DC resistance | MT 818.11 | 6.4.2.6 | T | T | GB/T 3048.4 |
10 | Insulation mechanical and physical properties test |
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10.1 | Mechanical properties test before aging | MT 818.11 | 6.4.3.1 | T | T | GB/T 2951.1 |
10.2 | Mechanical properties test after aging | MT 818.11 | 6.4.3.1 | T | T | GB/T 2951.2 |
11 | Sheath mechanical and physical properties test |
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11.1 | Mechanical properties test before aging | MT 818.11 | 6.4.3.2 | T | T | GB/T 2951.1 |
11.2 | Mechanical properties test after aging | MT 818.11 | 6.4.3.2 | T | T | GB/T 2951.2 |
12 | Additional aging test for finished cable segments | MT 818.11 | 6.4.3.3 | T | T | 6.4.3.3 in MT 818.11 |
13 | High temperature pressure test for PVC insulation and sheath | MT 818.11 | 6.4.3.5 | T | T | GB/T 2951.6 |
14 | Low temperature performance test for PVC insulation and sheath | MT 818.11 | 6.4.3.6 | T | T | GB/T 2951.4 |
15 | Crack resistance of PVC insulation and sheath(thermal shock) test | MT 818.11 | 6.4.3.7 | T | T | GB/T 2951.6 |
16 | Water absorption test for PVC insulation | MT 818.11 | 6.4.3.8 | T | T | GB/T 2951.3 |
17 | Special bending test | MT 818.11 | 6.4.3.12 | T | T | 6.4.3.12 in MT 818.11 |
18 | Printed mark rub resistance test | MT 818.11 | 6.4.4 | T | T | GB 6995 |
Table 4 （continued）Test items
Serial number | Item name | Test requirements | Test type | Test method |
Standard number | Clause number | 0.6/1kV | 1.8/3kV |
19 | Flame retardant performance test |
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19.1 | Single vertical burning test | MT 818.11 | 6.4.5 | T | T | MT 386 |
19.2 | Burning test under load conditions | MT 818.11 | 6.4.5 | T | T | MT 386 |
19.3 | Bunched burning test | MT 818.11 | 6.4.5 | T | T | MT 386 |
1）Item 17 only applies to cables with structures specified in 5.4.3 of MT 818.11 |
