This detailed comparison of four mineral insulated cables—BTLY, YTTW, BBTRZ, and BTTZ—is provided for reference by industry colleagues, focusing on performance, specifications, and implementation standards.
Comparing flexible and rigid mineral insulated cables is essentially comparing BTLY and BTTZ cables. Rigidity versus flexibility depends primarily on the cable's structure. Rigid mineral cables, in addition to being inherently rigid, also offer exceptional impact resistance, with BTTZ cables being a representative example. Flexible mineral cables, while more flexible, offer relatively poor impact resistance.
How to distinguish between rigid and flexible mineral cables depends primarily on the model number. Each cable has its model number printed on it. Remember that cables classified as BTTZ are rigid, while the others are flexible (YTTW, NG-A, BTLY, and BBTRZ).
1. Fire Performance Comparison:
The NG-A (BTLY) flexible mineral insulated cable's fire resistance has been evaluated under the highest levels of the C, W, and Z tests of BS 6387:
(C) Burning at 950°C for 180 minutes
(W) Spraying at 650°C for 15 minutes, followed by another 15 minutes of spraying while continuing to burn
(Z) Impact at 950°C for 15 minutes/30 times
The fire ratings of YTTW and BBTRZ flexible mineral insulated cables are the same as those of BS 6387 CWZ.
BTTZ mineral insulated cable performance:
1) Continuously energized for 180 minutes under 950°C flame without breakdown;
2) 180 minutes under 950°C flame followed by 60 minutes of immersion in water without breakdown;
3) 180 minutes of impact and vibration under 950°C flame without breakdown;
Commonalities: Reliable inorganic mineral insulation, waterproof, rodent-proof, ant-proof, high mechanical strength, corrosion resistance, energy-saving and environmentally friendly, radiation-proof, and long life.
2. Comparison of core number, specifications, and cross-sectional area:
NG-A/BTLY: 1 core, 10-300 mm²; 2, 3, 4, and 5 cores, 2.5-300 mm²; 3+1, 3+2, and 4+1 cores, 4-300 mm².
YTTW: 1 core 10~630mm²; 2, 3, 4 core 2.5~120mm²; 3+1 core 16~120 mm².
BBTRZ: 1 core 10~500 mm²; 2, 3, 4, 5 core 1.5~400 mm²; 3+1, 3+2, 4+1 core 4~400 mm².
BTTZ: 1 core 1.5~400mm²; 2, 3, 4 cores 1.5~25mm²; 7, 10, 12 cores 1.5~2.5mm².
3. Implementation Standards:
Flexible Mineral Insulated Cable: JS/GY002-2017 Inorganic Mineral Insulated Flexible Fire-Resistant Cable, Rated Voltage 1kV and Below
Rigid Mineral Insulated Cable: National Standard/International Standard GB/T 13033/IEC 60702
4. Operating Temperature
NG-A (BTLY): Up to 1300°C
YTTW: Up to 950°C
BBTRZ: Up to 950°C
BTTZ: Up to 1000°C
5. Insulation Material Comparison
NG-A, BTLY: Double-sided mica tape + ceramic tape
YTTW: Phlogopite tape
BBTRZ: Phlogopite tape + XLPE
BTTZ: Magnesium oxide
6. Installation Conditions
Flexible Mineral Insulated Cable: Requires enclosed cable tray or conduit protection (YTTW can be installed in the open without cable tray or conduit).
Rigid Mineral Insulated Cable: Can be installed in the open without cable tray or conduit.
7. Service Life Comparison
Flexible Mineral Insulated Cable: 50-100 years
Rigid Mineral Insulated Cable: Over 100 years
